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Indoor Counterpoise For Random Wire Antenna
I am using a random wire antenna which runs outdoors through a hole in a
window frame. I do not have access to any good RF grounding system and plan to use an indoor counterpoise wire from the ground connection on the tuner (MFJ-949E). I have a nice role of #18 wire, the end is connected to the tuner, and it is my intention to unroll it along the floor through my suite until such time as it is properly tuned. MY QUESTION IS - How can I tell when I have unrolled the right amount of wire for the frequency in use. I know it will not be 1/4 wave, and that it should be less. From what I understand, when it is adjusted properly I should not have any hot RF burning my lips from the mike. Checking it with my lips is not what I call a desireable means of testing, and being single I cannot call my wife to test it for me. I'd like to find a better way and hence my questions. I believe (according to what theory I have learned) that the tuner chassis would be hot with RF, with the amount of RF becoming less and less as the counterpoise wire approaches the proper length. If this is true would a simple RF sniffer tell me? I can rig one up fairly easily. OR - What would I be looking for using my MFJ-259B SWR Analyzer? I expect what it would show readings similar to a dipole with resonance at the operating frequency and an impedance (resistive) of somewhere in the order of 60 ohms. plus or minus -- is this a correct assumption? OR -- does anyone on the group have any suggestions that will tell me when the system is properly adjusted -- the simpler the better! Once I have found how to do this, I can put tape markings on the roll of counterpoise wire to show the appropriate length for each band or narrow band of frequencies in which I will be operating. I have already tested the hole -- it is just a little less than 1/4 inch diamater, but that seems to be enough to let both sidebands through -- I carefully tested that using AM which proves that two sidebands can fit through the hole at the same time, which allows me to further assume that either the upper or lower sidebands should squeeze through easily! :-) Thanks in advance for any assistance you can provide in this matter. Irv VE6BP On the air finally but afraid to get to close to the mike! I may have to use rubber gloves and teflon lip gloss! |
Indoor Counterpoise For Random Wire Antenna
"Irv Finkleman" wrote in message ... snip I should not have any hot RF burning my lips from the mike. Checking it with my lips is not what I call a desireable means of testing, and being single I cannot call my wife to test it for me. I'd like to find a better way and hence my questions. Since you started this whimsical line of reasoning, you dare not object: Buy a plastic microphone. Har-har-HAR-dee-har-har! [Thanks to Ralph Kramden] But seriously folks ... You do have a coaxial cable from the radio to the tuner. Choke the bejabbers out of it. Either wind the coax itself into one or more physical coil(s) of the right proportions or use the W2DU method. This will be useful for the former approach: http://www.karinya.net/g3txq/temp/choke_impedances.png It illustrates that no single coil really does it. .... and this for the latter: http://www.qsl.net/ta1dx/amator/W2du.jpg Although your application doesn't involve using beads as a balun, per the illustration, the broad approach is the same: blocking common mode currents. "Sal" who chokes his cables and gets no shocks I believe (according to what theory I have learned) that the tuner chassis would be hot with RF, with the amount of RF becoming less and less as the counterpoise wire approaches the proper length. If this is true would a simple RF sniffer tell me? I can rig one up fairly easily. OR - What would I be looking for using my MFJ-259B SWR Analyzer? I expect what it would show readings similar to a dipole with resonance at the operating frequency and an impedance (resistive) of somewhere in the order of 60 ohms. plus or minus -- is this a correct assumption? OR -- does anyone on the group have any suggestions that will tell me when the system is properly adjusted -- the simpler the better! Once I have found how to do this, I can put tape markings on the roll of counterpoise wire to show the appropriate length for each band or narrow band of frequencies in which I will be operating. I have already tested the hole -- it is just a little less than 1/4 inch diamater, but that seems to be enough to let both sidebands through -- I carefully tested that using AM which proves that two sidebands can fit through the hole at the same time, which allows me to further assume that either the upper or lower sidebands should squeeze through easily! :-) Thanks in advance for any assistance you can provide in this matter. Irv VE6BP On the air finally but afraid to get to close to the mike! I may have to use rubber gloves and teflon lip gloss! |
You shouldn't need to unroll the wire at all since you're using a tuner. Just hook it up and tune away.
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Indoor Counterpoise For Random Wire Antenna
Irv,
I think you will find it difficult to tune up using a MFJ-949E, random wire antenna and a roll of wire run around your apartment. You will probably end up with a "hot mike" most of the time. Even if you get it all tuned up on one frequency as soon as you QSY to a different frequency you will have to change the counterpoise wire length. Finding the right lengths for different frequencies and coiling/uncoiling the wire each time you QSY will get old fast. I have a better solution for you. Buy an MFJ artificial ground so that you can use a fixed length of wire under the carpet and tune the counterpoise from the operating position. MFJ makes a standalone product called the MFJ-931 or a tuner that includes the artificial ground - MFJ-934. Here are some links to these products: http://www.mfjenterprises.com/Produc...ductid=MFJ-931 http://www.mfjenterprises.com/Produc...ductid=MFJ-934 Hope things work out for you and that you get back on the air in the near future. Let us know how things work out for you. Roger |
Indoor Counterpoise For Random Wire Antenna
On Tue, 24 Apr 2012 16:08:10 -0600, "Irv Finkleman"
wrote: I am using a random wire antenna which runs outdoors through a hole in a window frame. I do not have access to any good RF grounding system and plan to use an indoor counterpoise wire from the ground connection on the tuner (MFJ-949E). I have a nice role of #18 wire, the end is connected to the tuner, and it is my intention to unroll it along the floor through my suite until such time as it is properly tuned. MY QUESTION IS - How can I tell when I have unrolled the right amount of wire for the frequency in use. I once had the little B&W vertical in a 3rd story apartment window. To tune it, I used an SWR meter and simply unrolled my single counterpoise wire across the rug until the swr was 1:1 for the band in use. The counterpoise was on a wire spool. I never actually measured the counterpoise length -- I simply found 40 meters meant the wire went from the bedroom window to the kitchen. bob k5qwg I know it will not be 1/4 wave, and that it should be less. From what I understand, when it is adjusted properly I should not have any hot RF burning my lips from the mike. Checking it with my lips is not what I call a desireable means of testing, and being single I cannot call my wife to test it for me. I'd like to find a better way and hence my questions. I believe (according to what theory I have learned) that the tuner chassis would be hot with RF, with the amount of RF becoming less and less as the counterpoise wire approaches the proper length. If this is true would a simple RF sniffer tell me? I can rig one up fairly easily. OR - What would I be looking for using my MFJ-259B SWR Analyzer? I expect what it would show readings similar to a dipole with resonance at the operating frequency and an impedance (resistive) of somewhere in the order of 60 ohms. plus or minus -- is this a correct assumption? OR -- does anyone on the group have any suggestions that will tell me when the system is properly adjusted -- the simpler the better! Once I have found how to do this, I can put tape markings on the roll of counterpoise wire to show the appropriate length for each band or narrow band of frequencies in which I will be operating. I have already tested the hole -- it is just a little less than 1/4 inch diamater, but that seems to be enough to let both sidebands through -- I carefully tested that using AM which proves that two sidebands can fit through the hole at the same time, which allows me to further assume that either the upper or lower sidebands should squeeze through easily! :-) Thanks in advance for any assistance you can provide in this matter. Irv VE6BP On the air finally but afraid to get to close to the mike! I may have to use rubber gloves and teflon lip gloss! |
Indoor Counterpoise For Random Wire Antenna
Thanks Sal, Roger, and Bob as well as
the many others who have not yet replied -- actually my mic is plastic. I truly appreciate your assistance, but I think I really need to explain my rationale somewhat. The real intent of my questioning is to provide a counterpoise system whereas the tuner does not just have an unbalance by simply feeding the random wire, but a balance achieved whereby the counterpoise connected to the tuner acts as the other (missing) half of the unbalanced system, thereby balancing it just as the ground image does with a quarter wave antenna. Does this make sense? If not, wait till you read further about MFJ and the push and pull explanation. I have two tuners at my disposal -- one is an MFJ-949E Deluxe Versa Tuner II -- a common T match configuration. The other is an MFJ-1625 Window/Balcony Mount Antenna which contains matching circuitry and also a loading coil for tuning the counterpoise wire or wires. I hope to use the 949E, if I can resolve the matter of knowing when the counterpoise is properly adjusted. It is this matter that I am trying to resolve to my satisfaction. I could equally use the MFJ-1625 which is just an MFJ-1623 with a 12 ft whip and an 80m loading coil. I'm fairly well read on antennas, but still my knowledge of this monumental subject is very limited i.e. to me a Smith Chart is something belonging to a hospital patient named Smith. I sort of understand the concept of the counterpoise acting as the missing half of the system, but have difficulty putting it into words. MFJ, in the MFJ-1625 Manual say.... QUOTE It is always important to have a good RF ground, provided by the counterpoise, when using any whip or long-wire antenna. This is because the MFJ-1623 tuner needs something to "push" against in order to force current into the antenna. If a good RF ground is not available, RF will usually find its way back into the power line (RFI), transmitter audio circuits (RF feedback), or the operator (RF burns). Water pipes provide good dc and ac safety grounds, but they are often inadequate for RF grounding because they are long single conductors. RF grounds require large "spread out" surfaces with direct multiple connections to the equipment ground point. Water pipes, heating ducts, or multiple ground rods may work (especially if they are all connected together with jumper wires), but the best RF grounds are radial systems or multi-wire counterpoises. UNQUOTE I have to admit that this explanation contains terms like long-wire antenna used in what I think might be confusing or ill-defined ways, but the idea of push and pull of antenna current feels right. If this is not already confusing, it is the MFJ-1625 Manual, but the tuner is an MFJ-1623. Many hams use the term MFJ as standing for 'Mighty Fine Junk', and at times I agree, but I do have good skills as a technicial and find that a little resoldering and tightening of ground nuts turns it into somewhat better than any of the homebrew or modifications I have ever put on the air. I no longer have a house, shack, workshop, and tower, etc,etc,etc and am now working with largely storebought items and limited space. I have considered a cabin in the mountains where I would not interfere with anyone around, but where would I find one with built in housekeeping and meals? Just the expense of the extension cord alone makes me shudder. I am not as concerned about a case of 'rf lip' as I am about stray RF causing possible problems with the neighbours on all sides of me, with all my electronic toys such as computers, DVD players, the local fire-alarm system and other such things. The last thing I want to do is draw attention to the fact that I am running a ham radio station from my suite until I know I am not causing any problems. Thusly, my goal is to provide myself with a first rate RF ground system, entirely contained within my suite, in order that I do not wake up at night with the fire alarms set off and great numbers of disturbed residents gathered around pointing at me and saying 'Ham! Ham! For Shame! For Shame!' and the Residents Council having special meetings to decide how to deal with me. They already think I'm crazy -- and I may be somewhat, but I don't want to make matters worse! So, having herein explained my rational, lets see what help I can get in the way of producing the ideal indoor low-cost non-radiating counterpoise radial system. Actually, I have lots of wire for the radials, the tuner contains a loading coil to assist in tuning the counterpoise, and my big concern is how do I determine when the counterpoise is operating effectively. The metering system in the tuner should reach a peak and subside on either side of the correct counterpoise tuning point, and what I really need to know is how to determine when the stray RF is minimized if not eliminated. I have to explain that I do all this in a somewhat humorous manner, I find all my predicaments funny, but then I brought myself into them and this is the only way, short of outright denial, of dealing with them. You have probably already noticed that I am a man of few words! Irv VE6BP P.S. In a previous topic where the matter of electrons escaping from the end of the antenna was hotly debated, I have solved that problem by forming a wee loop at the end of the antenna, thereby taking any of those loose electrons and feeding them back into the wire! I used the loop and a nylon cable tie to fasten the end of theantenna into the tree which supports most of it, thereby eliminating the cost of a ceramic insulator and it's accompanying end effect. I'm sure Tesla and Marconi could have used some of my simple practical solutions like this one, and perhaps negated the necessity of long discussions re electrons escaping from antennas. "Irv Finkleman" wrote in message ... I am using a random wire antenna which runs outdoors through a hole in a window frame. I do not have access to any good RF grounding system and plan to use an indoor counterpoise wire from the ground connection on the tuner (MFJ-949E). I have a nice role of #18 wire, the end is connected to the tuner, and it is my intention to unroll it along the floor through my suite until such time as it is properly tuned. MY QUESTION IS - How can I tell when I have unrolled the right amount of wire for the frequency in use. I know it will not be 1/4 wave, and that it should be less. From what I understand, when it is adjusted properly I should not have any hot RF burning my lips from the mike. Checking it with my lips is not what I call a desireable means of testing, and being single I cannot call my wife to test it for me. I'd like to find a better way and hence my questions. I believe (according to what theory I have learned) that the tuner chassis would be hot with RF, with the amount of RF becoming less and less as the counterpoise wire approaches the proper length. If this is true would a simple RF sniffer tell me? I can rig one up fairly easily. OR - What would I be looking for using my MFJ-259B SWR Analyzer? I expect what it would show readings similar to a dipole with resonance at the operating frequency and an impedance (resistive) of somewhere in the order of 60 ohms. plus or minus -- is this a correct assumption? OR -- does anyone on the group have any suggestions that will tell me when the system is properly adjusted -- the simpler the better! Once I have found how to do this, I can put tape markings on the roll of counterpoise wire to show the appropriate length for each band or narrow band of frequencies in which I will be operating. I have already tested the hole -- it is just a little less than 1/4 inch diamater, but that seems to be enough to let both sidebands through -- I carefully tested that using AM which proves that two sidebands can fit through the hole at the same time, which allows me to further assume that either the upper or lower sidebands should squeeze through easily! :-) Thanks in advance for any assistance you can provide in this matter. Irv VE6BP On the air finally but afraid to get to close to the mike! I may have to use rubber gloves and teflon lip gloss! |
Indoor Counterpoise For Random Wire Antenna
"Irv Finkleman" wrote in message ... The real intent of my questioning is to provide a counterpoise system whereas the tuner does not just have an unbalance by simply feeding the random wire, but a balance achieved whereby the counterpoise connected to the tuner acts as the other (missing) half of the unbalanced system, thereby balancing it just as the ground image does with a quarter wave antenna. Does this make sense? Yes and perhaps I have a workable idea to get there. First, an assumption: Your long wire out the window frame has only a short run to the tuner. That is, the tuner is on the same wall as the window frame and is near the window. How'm I doing so far? Along that same wall, stretch out a heavy piece of straight wire -- can be insulated but you'll cut through the insulation as needed -- from corner to corner. It's like a workbench ground bus but it's not grounded, per se. Attach the tuner ground to it. Buy two (maybe more) locking metal tape rules. Craftsman, Lever-lock. At the zero ends, securely bolt or clamp the metal tape rules to the ends of the heavy wire in each corner. Yes, you're ruining the tape rules by mutilating the ends but we know you're desperate. Courage, man! Stretch out the tape rules until their lengths become whatever you need for a workable counterpoise, recalling that HF antenna elements (and counterpoises) do not need to run in perfect straight lines. Zig-zagging is your friend in a confined space. Even go up the wall(s) in the far corners. This method, if it works, has a bonus. Once the lengths are established for each band, the exact lengths can be eyeballed directly off the tape rules and noted. Alternatively, just scrawl band numbers on the walls. (Hi-hi) "Sal" Never one to let anything serve only a single purpose. |
Indoor Counterpoise For Random Wire Antenna
"Irv Finkleman" napisał w wiadomości ... MFJ, in the MFJ-1625 Manual say.... QUOTE It is always important to have a good RF ground, provided by the counterpoise, when using any whip or long-wire antenna. This is because the MFJ-1623 tuner needs something to "push" against in order to force current into the antenna. If a good RF ground is not available, RF will usually find its way back into the power line (RFI), transmitter audio circuits (RF feedback), or the operator (RF burns). Water pipes provide good dc and ac safety grounds, but they are often inadequate for RF grounding because they are long single conductors. You wrote: " I have a nice role of #18 wire, the end is connected to the tuner, and it is my intention to unroll it along the floor through my suite until such time as it is properly tuned." So it will be: "a long single conductors" RF grounds require large "spread out" surfaces with direct multiple connections to the equipment ground point. Water pipes, heating ducts, or multiple ground rods may work (especially if they are all connected together with jumper wires), but the best RF grounds are radial systems or multi-wire counterpoises. So you should not unroll it but have "all connected together with jumper wires". Jta is the same opinion: "You shouldn't need to unroll the wire at all since you're using a tuner. Just hook it up and tune away." The hook = jumped wire. P.S. In a previous topic where the matter of electrons escaping from the end of the antenna was hotly debated, I'm sure Tesla and Marconi could have used some of my simple practical solutions like this one, and perhaps negated the necessity of long discussions re electrons escaping from antennas. There was also Sir Oliver Lodge. He demonstrated the escaping of electrons from the antinodes (see Fig. 2): He also discovered that HF do not like the long conductors; "The electrical charge stored in the Leyden jars could flow either through the very low dc resistance path provided by the loop of wire or it could flow across the very high resistance path through the air between the spark-gap terminals at B. It would seem that the obvious path for the charge to follow would be through the low resistance wire loop. Surprisingly, Lodge was able to produce very large sparks across the spark-gap, B, even though the dc resistance of the wire across the gap was only a fraction of an ohm.[4]" I am trying to "descend you into the same bottomless pit" S* |
Indoor Counterpoise For Random Wire Antenna
"Sal" wrote in message ... "Irv Finkleman" wrote in message ... The real intent of my questioning is to provide a counterpoise system whereas the tuner does not just have an unbalance by simply feeding the random wire, but a balance achieved whereby the counterpoise connected to the tuner acts as the other (missing) half of the unbalanced system, thereby balancing it just as the ground image does with a quarter wave antenna. Does this make sense? Yes and perhaps I have a workable idea to get there. First, an assumption: Your long wire out the window frame has only a short run to the tuner. That is, the tuner is on the same wall as the window frame and is near the window. How'm I doing so far? Bang on Sal -- the tuner is located about 18 inches from where the wire comes through the window, but on the floor along the wall with the window is the baseboard hot water heating unit so I can't really run anything on the floor along that wall. Similarly, although I understand your tape measure idea, there is a simpler solution which I tested last night and worked perfectly. I arrived at a solution through the following note from Bob, K5QWG who wrote: "I once had the little B&W vertical in a 3rd story apartment window. To tune it, I used an SWR meter and simply unrolled my single counterpoise wire across the rug until the swr was 1:1 for the band in use. The counterpoise was on a wire spool. I never actually measured the counterpoise length -- I simply found 40 meters meant the wire went from the bedroom window to the kitchen." I thought it made perfect sense and even downloaded the instruction manual for the B&W AP-10 Windowsill Antenna which told me the same thing as Bob wrote -- and it worked perfectly. I too used a spool of wire connected to the ground post on the MFJ-949E tuner, and unrolled it away from the tuner and antenna, across the floor and through the room. At that point I tuned up on frequency, adjusted the tuner for minimum SWR (nearly 1 to 1) and that was that! It worked beautifully. Your idea with the tape measures would have worked as well, but would have been a little more expensive and possibly unworkable due to the heater. Instead, I simply put a tape marker on the counterpoise wire at the length where it worked well on the band tested (80M). Now, when I want to operate all I have to do is unroll the spool to the tape marker and Presto! I can go on the air! Of course I have noted the tuner settings, and will also add further tape markers on the counterpoise wire for the different bands, and note the tuner settings as well. My next step may be to cut counterpoise wires for each band of operation and permanently lay them along the wall this negating the need to roll and unroll the spool of wire each time. With time there may be some minor changes. For instance how far across the bands can I tune without any significant change in SWR. I might also try putting a loading coil in the counterpoise line at the tuner end so that I can fine tune the counterpoise length electrically. I will build up a little RF sniffer just to check for local stray rf but that should no longer be a problem. I could use the MFJ-1625 tuner which has a built in switched coil to adjust the counterpoise, but it only has a current meter, not an swr bridge. The MFJ-949E tuner has swr metering. Therefore if the loading coil for the counterpoise works, I can use the 949E and sell (albeit at a small loss hopefully) the MFJ-1625 set complete to some ham who is able to operate using the intended setup for the 1625. It is an excellent system, but because of all the metal in my building which negates indoor operation, and the inability to put the whip out of the window due to physical limitations existing in my suite, I cannot use it. I had not considered the limittions in my situation prior to buying the 1625 but it was worth the try. I might even keep it (I may have to if I can't sell it) for portable use when I go fishing. It would be an excellent setup on a picnic table or from a tent. Again, time will tell, In any event, A BIG THANK You to all who helped in this discussion -- I can now get on the air and as soon as I have things tested and tidied up I hope to meet you there. Irv, VE6BP |
Indoor Counterpoise For Random Wire Antenna
On Tuesday, April 24, 2012 9:11:06 PM UTC-7, Irv Finkleman wrote:
Thusly, my goal is to provide myself with a first rate RF ground system, entirely contained within my suite, in order that I do not wake up at night with the fire alarms set off and great numbers of disturbed residents gathered around pointing at me and saying 'Ham! Ham! For Shame! For Shame!' and the Residents Council having special meetings to decide how to deal with me. They already think I'm crazy -- and I may be somewhat, but I don't want to make matters worse! So, having herein explained my rational, lets see what help I can get in the way of producing the ideal indoor low-cost non-radiating counterpoise radial system. Actually, I have lots of wire for the radials, the tuner contains a loading coil to assist in tuning the counterpoise, and my big concern is how do I determine when the counterpoise is operating effectively. The metering system in the tuner should reach a peak and subside on either side of the correct counterpoise tuning point, and what I really need to know is how to determine when the stray RF is minimized if not eliminated. Irv, Nice to hear that you got something working and are back on the air. However I want to point out some incorrect assumptions you made earlier about RFI and stray RF from counterpoises. The subject of radiating counterpoises in an apartment was discussed in this Usenet group a few years ago. Here is a link that provides some more info for you. How much does a counterpoise radiate? - http://www.radiobanter.com/showthread.php?t=117807 The counterpoise you have inside your apartment will definitely radiate into the building as will the length of antenna running from the tuner to the hole in the window. In another post you said you were running QRP at 5 watts. You may not have any RFI problems with other electronics in your building at these low levels. If you crank up the power to 100 watts I don't think you will be so lucky... |
Indoor Counterpoise For Random Wire Antenna
In article ,
Irv Finkleman wrote: I am not as concerned about a case of 'rf lip' as I am about stray RF causing possible problems with the neighbours on all sides of me, with all my electronic toys such as computers, DVD players, the local fire-alarm system and other such things. The last thing I want to do is draw attention to the fact that I am running a ham radio station from my suite until I know I am not causing any problems. Thusly, my goal is to provide myself with a first rate RF ground system, entirely contained within my suite, in order that I do not wake up at night with the fire alarms set off and great numbers of disturbed residents gathered around pointing at me and saying 'Ham! Ham! For Shame! For Shame!' and the Residents Council having special meetings to decide how to deal with me. They already think I'm crazy -- and I may be somewhat, but I don't want to make matters worse! So, having herein explained my rational, lets see what help I can get in the way of producing the ideal indoor low-cost non-radiating counterpoise radial system. Irv, Your goals are certainly valid. As far as preventing RF from going where you don't want it to... the main issue MJF is talking about here is "conducted" RF. The RF energy on the "ground" side of your antenna connector is going to flow outwards through every conductive path available to it, including the "counterpoise" side of your antenna arrangement, and anything connected directly or indirectly to your rig's chassis (e.g. to the power supply and then onto the third "ground" wire in the household mains). The amount of current flowing through each of these paths will depend on the RF impedance of the path, with more current flowing through paths of lower impedance. So, what you want is (probably) to have one or more counterpoise wires whose RF impedance is as low as practical, at the frequency in question. These could be quarter-wave wires, or they could be shorter or longer wires with an "active ground" (which is essentially a simple "antenna tuner" on the ground side, with an adjustable reactance to cancel out some of the reactance of a non-quarterwave wire). You can also help keep RF "where it belongs" by adding common-mode chokes to your rig power cables, thus increasing the RF impedance of this path and helping reduce the amount of current which is conducted back into the building ground. Another approach which may help, is to consider using an end-fed half-wave antenna, with a specifically-wound matching coil system. These are (in principle at least) largely ground-independent... the low-impedance side of the matching coil provides good RF paths for both the "hot" and "ground" sides of the antenna connection, and when properly adjusted they don't dump much RF into the rig ground or counterpoise. These techniques may not help much, if at all, with *radiated* RF getting into places you don't want it. Even if you have an antenna which is fully balanced, and completely isolated from the building ground (e.g. battery powered), the "near field" RF from the antenna can be coupled into the building wiring, and start causing interference and "undesired operation". Unfortunately, a lot of consumer and industrial electronic equipment these days is very vulnerable to this... poor shielding/filtering. Speaker cables, telephone and alarm wiring, etc. can all act as antennas. Not much you can do about this except try to route your antenna and counterpoise wires as far away from other wiring as possible, keep your transmission power down, and try to transmit during times when people are asleep. -- Dave Platt AE6EO Friends of Jade Warrior home page: http://www.radagast.org/jade-warrior I do _not_ wish to receive unsolicited commercial email, and I will boycott any company which has the gall to send me such ads! |
Indoor Counterpoise For Random Wire Antenna
"Roger" wrote in message news:11291508.1749.1335373308176.JavaMail.geo-discussion-forums@pbbpz9... On Tuesday, April 24, 2012 9:11:06 PM UTC-7, Irv Finkleman wrote: Thusly, my goal is to provide myself with a first rate RF ground system, entirely contained within my suite, in order that I do not wake up at night with the fire alarms set off and great numbers of disturbed residents gathered around pointing at me and saying 'Ham! Ham! For Shame! For Shame!' and the Residents Council having special meetings to decide how to deal with me. They already think I'm crazy -- and I may be somewhat, but I don't want to make matters worse! So, having herein explained my rational, lets see what help I can get in the way of producing the ideal indoor low-cost non-radiating counterpoise radial system. Actually, I have lots of wire for the radials, the tuner contains a loading coil to assist in tuning the counterpoise, and my big concern is how do I determine when the counterpoise is operating effectively. The metering system in the tuner should reach a peak and subside on either side of the correct counterpoise tuning point, and what I really need to know is how to determine when the stray RF is minimized if not eliminated. # Irv, # Nice to hear that you got something working and are back on the air. However I want to point out some incorrect assumptions you made earlier about RFI and stray RF from counterpoises. # The subject of radiating counterpoises in an apartment was discussed in this Usenet group a few years ago. Here is a link that provides some more info for you. # How much does a counterpoise radiate? - http://www.radiobanter.com/showthread.php?t=117807 # The counterpoise you have inside your apartment will definitely radiate into the building as will the length of antenna running from the tuner to the hole in the window. In another post you said you were running QRP at 5 watts. You may not have any # RFI problems with other electronics in your building at these low levels. If you crank up the power to 100 watts I don't think you will be so lucky... - True. A few years back with 100 watts and an attic loop, I fried the solid state heat/AC thermostat. I put a ferrite choke on the leads of the new one. Wayne W5GIE |
Indoor Counterpoise For Random Wire Antenna
Thanks Roger -- I already knew that but didn't at all consider it
during my recent explorations into the counterpoise system. How I managed to ignore it defys explanation -- I keep asking myself how that occurred. I think it may have been a cross between psychological suggestion and some form of denial in wanting a good and clean signal. In particular I really enjoyed the tipoff to RadioBanter.com which I intend to explore more, and the discussions were informative. In particular, where there are links to other threads I found some of Reg Edwards material which has always been worthy of reading. I went to bed satisfied that I could now get on the air and not set off any alarms etc, and although I don't recall them when I woke up, I'm sure I must have dreamed about good times on the air again! I've been in and out of the hospital for a couple years and have not been on the air since about mid 2009. I'm better now and looking forward to lots of radio activity! As I mentioned in earlier posts, I have never been power hungry and have generally operated in the under 25 watt range -- now I'm going to be what I call 'ham flyfishing' i.e. QRP. Now I can do some further experimentation such as using individual counterpoise wires for each band, and possibly even a variable inductor to fine tune the counterpoise, and assorted things like that. I have never been as interested in operating as in the technical aspects -- especially the eternal search for the utopian small antenna/DX magnet. My DX interest extends only in so far as it is the on the air tests that tell you how well your antenna system is functioning given a non-adjustable set of propagation conditions. Now I have only to look forward to a good sunspot cycle and perhaps just a little more global warming to help me through those cold Alberta winters! What's your call? Where are you located? I saw a .ca somewhere but that doesn't tell me much. Thanks again, Irv VE6BP Gonna ham away my 'golden years'! "Roger" wrote in message news:11291508.1749.1335373308176.JavaMail.geo-discussion-forums@pbbpz9... On Tuesday, April 24, 2012 9:11:06 PM UTC-7, Irv Finkleman wrote: Thusly, my goal is to provide myself with a first rate RF ground system, entirely contained within my suite, in order that I do not wake up at night with the fire alarms set off and great numbers of disturbed residents gathered around pointing at me and saying 'Ham! Ham! For Shame! For Shame!' and the Residents Council having special meetings to decide how to deal with me. They already think I'm crazy -- and I may be somewhat, but I don't want to make matters worse! So, having herein explained my rational, lets see what help I can get in the way of producing the ideal indoor low-cost non-radiating counterpoise radial system. Actually, I have lots of wire for the radials, the tuner contains a loading coil to assist in tuning the counterpoise, and my big concern is how do I determine when the counterpoise is operating effectively. The metering system in the tuner should reach a peak and subside on either side of the correct counterpoise tuning point, and what I really need to know is how to determine when the stray RF is minimized if not eliminated. Irv, Nice to hear that you got something working and are back on the air. However I want to point out some incorrect assumptions you made earlier about RFI and stray RF from counterpoises. The subject of radiating counterpoises in an apartment was discussed in this Usenet group a few years ago. Here is a link that provides some more info for you. How much does a counterpoise radiate? - http://www.radiobanter.com/showthread.php?t=117807 The counterpoise you have inside your apartment will definitely radiate into the building as will the length of antenna running from the tuner to the hole in the window. In another post you said you were running QRP at 5 watts. You may not have any RFI problems with other electronics in your building at these low levels. If you crank up the power to 100 watts I don't think you will be so lucky... |
Indoor Counterpoise For Random Wire Antenna
On Wednesday, April 25, 2012 11:47:55 AM UTC-7, Irv Finkleman wrote:
In particular I really enjoyed the tipoff to RadioBanter.com which I intend to explore more, and the discussions were informative. In particular, where there are links to other threads I found some of Reg Edwards material which has always been worthy of reading. Irv, If you found the radio banter discussion interesting you will really enjoy the forum on restrictive antennas at eham. Pages and pages of stuff written by hams living in condos, HOA and apartments. Here is the link.... http://www.eham.net/ehamforum/smf/in...board,2.0.html Now that you are feeling better you can start having some fun back on the bands. You might find some of the digital modes like PSK31, WSPR etc. fun and they don't generate "recognizable RFI" like CW and SSB. Roger |
Indoor Counterpoise For Random Wire Antenna
On 4/25/2012 2:56 AM, Szczepan Bialek wrote:
He also discovered that HF do not like the long conductors; "The electrical charge stored in the Leyden jars could flow either through Leyden jars? You're back that far? That's over 250 years ago! They had no idea of RF then! You really need to look at things that aren't so old. The authors you are reading have been proven WRONG when it comes to antennas and a good bit of everything else related to electricity. tom K0TAR |
Indoor Counterpoise For Random Wire Antenna
Thanks for your reply Dave,
I'm learning a lot in a hurry, finding out that grounds can be just as complex as antennas, and all about the interelationship between the two. I do have chokes on the power cord of my 12v supply and also on the supply cord between the PS and the rig. Your half wave suggestion is not immediately forthcoming due to the physical limitations I face here however it is on my list of possible future condierations. As per a previous post I have recently come into a treasure trove of inductors and capacitors -- variables of every type and sixe. With all this at my disposalI plan to fiddle about with tunable counterpoises, artificial grounds, and combinations thereof. At least I'm on the air again, but because I gave all my gear away I've had to jump from old tube rigs into a QRP world with a teensy Yaesu Ft-817 that it appears will take some time to learn to operate with all its menus, settings, and such. I have to get new glasses and perhaps a magnifier too. The saving grace here is QRP with which I hope to get into as little trouble as possible. I'm a pretty good tech, and have fixed up and modified lots of stuff but now I'm going to have to do a lot of learning in the wild world of wire antennas and grounds. Thanks for your good suggestions, and for taking the time to reply. 73 Irv VE6BP "Dave Platt" wrote in message ... In article , Irv Finkleman wrote: I am not as concerned about a case of 'rf lip' as I am about stray RF causing possible problems with the neighbours on all sides of me, with all my electronic toys such as computers, DVD players, the local fire-alarm system and other such things. The last thing I want to do is draw attention to the fact that I am running a ham radio station from my suite until I know I am not causing any problems. Thusly, my goal is to provide myself with a first rate RF ground system, entirely contained within my suite, in order that I do not wake up at night with the fire alarms set off and great numbers of disturbed residents gathered around pointing at me and saying 'Ham! Ham! For Shame! For Shame!' and the Residents Council having special meetings to decide how to deal with me. They already think I'm crazy -- and I may be somewhat, but I don't want to make matters worse! So, having herein explained my rational, lets see what help I can get in the way of producing the ideal indoor low-cost non-radiating counterpoise radial system. Irv, Your goals are certainly valid. As far as preventing RF from going where you don't want it to... the main issue MJF is talking about here is "conducted" RF. The RF energy on the "ground" side of your antenna connector is going to flow outwards through every conductive path available to it, including the "counterpoise" side of your antenna arrangement, and anything connected directly or indirectly to your rig's chassis (e.g. to the power supply and then onto the third "ground" wire in the household mains). The amount of current flowing through each of these paths will depend on the RF impedance of the path, with more current flowing through paths of lower impedance. So, what you want is (probably) to have one or more counterpoise wires whose RF impedance is as low as practical, at the frequency in question. These could be quarter-wave wires, or they could be shorter or longer wires with an "active ground" (which is essentially a simple "antenna tuner" on the ground side, with an adjustable reactance to cancel out some of the reactance of a non-quarterwave wire). You can also help keep RF "where it belongs" by adding common-mode chokes to your rig power cables, thus increasing the RF impedance of this path and helping reduce the amount of current which is conducted back into the building ground. Another approach which may help, is to consider using an end-fed half-wave antenna, with a specifically-wound matching coil system. These are (in principle at least) largely ground-independent... the low-impedance side of the matching coil provides good RF paths for both the "hot" and "ground" sides of the antenna connection, and when properly adjusted they don't dump much RF into the rig ground or counterpoise. These techniques may not help much, if at all, with *radiated* RF getting into places you don't want it. Even if you have an antenna which is fully balanced, and completely isolated from the building ground (e.g. battery powered), the "near field" RF from the antenna can be coupled into the building wiring, and start causing interference and "undesired operation". Unfortunately, a lot of consumer and industrial electronic equipment these days is very vulnerable to this... poor shielding/filtering. Speaker cables, telephone and alarm wiring, etc. can all act as antennas. Not much you can do about this except try to route your antenna and counterpoise wires as far away from other wiring as possible, keep your transmission power down, and try to transmit during times when people are asleep. -- Dave Platt AE6EO Friends of Jade Warrior home page: http://www.radagast.org/jade-warrior I do _not_ wish to receive unsolicited commercial email, and I will boycott any company which has the gall to send me such ads! |
Indoor Counterpoise For Random Wire Antenna
Hey Tom -- have you got the right topic here?
Irv VE6BP "tom" wrote in message . net... On 4/25/2012 2:56 AM, Szczepan Bialek wrote: He also discovered that HF do not like the long conductors; "The electrical charge stored in the Leyden jars could flow either through Leyden jars? You're back that far? That's over 250 years ago! They had no idea of RF then! You really need to look at things that aren't so old. The authors you are reading have been proven WRONG when it comes to antennas and a good bit of everything else related to electricity. tom K0TAR |
Indoor Counterpoise For Random Wire Antenna
On 4/25/2012 9:03 PM, Irv Finkleman wrote:
Hey Tom -- have you got the right topic here? Irv VE6BP wrote in message . net... On 4/25/2012 2:56 AM, Szczepan Bialek wrote: He also discovered that HF do not like the long conductors; "The electrical charge stored in the Leyden jars could flow either through Leyden jars? You're back that far? That's over 250 years ago! They had no idea of RF then! You really need to look at things that aren't so old. The authors you are reading have been proven WRONG when it comes to antennas and a good bit of everything else related to electricity. tom K0TAR Possibly not, my connection to the news server hiccuped badly for about a half hour and a response didn't get posted. It was to our wonderful source of knowledge Blaupunkt Szechuan. I have no idea how it got posted to this thread, but I'd like to. tom K0TAR |
Indoor Counterpoise For Random Wire Antenna
On 4/25/2012 9:22 PM, tom wrote:
On 4/25/2012 9:03 PM, Irv Finkleman wrote: Hey Tom -- have you got the right topic here? Irv VE6BP wrote in message . net... On 4/25/2012 2:56 AM, Szczepan Bialek wrote: He also discovered that HF do not like the long conductors; "The electrical charge stored in the Leyden jars could flow either through Leyden jars? You're back that far? That's over 250 years ago! They had no idea of RF then! You really need to look at things that aren't so old. The authors you are reading have been proven WRONG when it comes to antennas and a good bit of everything else related to electricity. tom K0TAR Possibly not, my connection to the news server hiccuped badly for about a half hour and a response didn't get posted. It was to our wonderful source of knowledge Blaupunkt Szechuan. I have no idea how it got posted to this thread, but I'd like to. tom K0TAR |
Indoor Counterpoise For Random Wire Antenna
On 4/25/2012 9:22 PM, tom wrote:
Possibly not, my connection to the news server hiccuped badly for about a half hour and a response didn't get posted. It was to our wonderful source of knowledge Blaupunkt Szechuan. I have no idea how it got posted to this thread, but I'd like to. tom K0TAR Wait a minute, that was correct. This was the response to Mister Blaupunkt. I had it right. tom K0TAR |
Indoor Counterpoise For Random Wire Antenna
"tom" wrote in message . net... SNIP Wait a minute, that was correct. This was the response to Mister Blaupunkt. I had it right. No, let's keep Sneezix Dip**** out of this thread. Please. |
Indoor Counterpoise For Random Wire Antenna
Thanks Sal -- I don't know what was happening -- it had
me wondering. Darned newfangled computers! :-) I'm spending the morning learning how to operate this little Yaesu FT-817ND -- it's going to take a bit of patience with all the menus and settings. I have a TS-820 I fixed up and gave to a chum who upgraded to a top of the linke TS-1Million or something and he offered it back to me. It would be a lot simpler, but one slip of the carrier or mic gain and I'm sure I'd totally reveal my thus far cleverly concealed ham radio operation! Thanks again for getting back to Tom on the Leyden jar matter! It really had me confused. Irv VE6BP "Sal" wrote in message ... "tom" wrote in message . net... SNIP Wait a minute, that was correct. This was the response to Mister Blaupunkt. I had it right. No, let's keep Sneezix Dip**** out of this thread. Please. |
Indoor Counterpoise For Random Wire Antenna
On 4/25/2012 10:38 PM, Sal wrote:
wrote in message No, let's keep Sneezix Dip**** out of this thread. Please. Unfortunately he is in this thread. Fortunately not much. I like your interpretation of his name much better than mine. tom K0TAR |
Indoor Counterpoise For Random Wire Antenna
On Wed, 25 Apr 2012 19:55:47 -0600, "Irv Finkleman"
wrote: At least I'm on the air again, but because I gave all my gear away I've had to jump from old tube rigs into a QRP world with a teensy Yaesu Ft-817 that it appears will take some time to learn to operate with all its menus, settings, and such. I have to get new glasses and perhaps a magnifier too. Light reading on the FT-817: http://www.ka7oei.com/ft817pg.shtml The saving grace here is QRP with which I hope to get into as little trouble as possible. As soon as the neighbors find out that you're a ham radio operator, several things will happen. 1. You will immediatly be blamed for all manner of electronic failures. Kitchen appliances, computer crashes, and prematurely dead batteries will all become your fault. 2. Neighbors will assume that you fix things for free. Training the neighbors to pay for your time will be a challenge. 3. The phone will ring at 2AM asking if you're on the air and causing reception problems with OTA TV, cable TV, satellite TV, etc. I'm a pretty good tech, and have fixed up and modified lots of stuff but now I'm going to have to do a lot of learning in the wild world of wire antennas and grounds. My theory is that if it doesn't work on paper, it's not going to work when you build it. There are plenty of "standard" antennas that usually work the first time (if you follow instructions). However, you seem to be interested in designing your own. Therefore, I suggest you download the demo version of EZNEC, or the free 4NEC2, and proceed to model your prospective antenna system. When the computah says that you're close, then it's time to build it. An MFJ269 or similar antenna analyzer is handy for verifying your calculations. Hint: One of my ham friends moved into a CC&R (covenants, conditions and restrictions) infested condo farm. No antennas of any kind. The condo council had at least one member that was certain that property values would decline if a ham was allowed to operate from the condo farm. So, I leaned a 20ft aluminum extension ladder against the house and ran a wire to the radio. It worke quite well with a tuner. The ladder was left leaning against the condo for a bit less than a year before the condo council discovered the ruse. There was a short debate. The council decided that since it had been in operation for a year without any complaints or detrimental effects, it could stay. -- Jeff Liebermann 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558 |
Indoor Counterpoise For Random Wire Antenna
"Jeff Liebermann" wrote in message ... snip I leaned a 20ft aluminum extension ladder against the house and ran a wire to the radio. It worke quite well with a tuner. The ladder was left leaning against the condo for a bit less than a year before the condo council discovered the ruse. There was a short debate. The council decided that since it had been in operation for a year without any complaints or detrimental effects, it could stay. -- Jeff Liebermann That is _so_ funny, I just got done mentioning my ladder experience! "Sal" big grin |
Indoor Counterpoise For Random Wire Antenna
"Jeff Liebermann" wrote in message ... On Wed, 25 Apr 2012 19:55:47 -0600, "Irv Finkleman" wrote: (assorted snips for brevity) Light reading on the FT-817: http://www.ka7oei.com/ft817pg.shtml Already been there and a few other places too, but thanks just the same. There are always new links popping up and I try to keep up with them too! As soon as the neighbors find out that you're a ham radio operator, several things will happen. 1. You will immediatly be blamed for all manner of electronic failures. Kitchen appliances, computer crashes, and prematurely dead batteries will all become your fault. 2. Neighbors will assume that you fix things for free. Training the neighbors to pay for your time will be a challenge. 3. The phone will ring at 2AM asking if you're on the air and causing reception problems with OTA TV, cable TV, satellite TV, etc. After mucho years on the air in mucho locations I can say I've been there, done that! This is however, my first real experience using a very limited antenna and QRP. My theory is that if it doesn't work on paper, it's not going to work when you build it. There are plenty of "standard" antennas that usually work the first time (if you follow instructions). However, you seem to be interested in designing your own. Therefore, I suggest you download the demo version of EZNEC, or the free 4NEC2, and proceed to model your prospective antenna system. When the computah says that you're close, then it's time to build it. An MFJ269 or similar antenna analyzer is handy for verifying your calculations. I have an MFJ-259B -- couldn't live without it, and with all the stuff I gave away this was the one thing that I just couldn't part with. Hint: One of my ham friends moved into a CC&R (covenants, conditions and restrictions) infested condo farm. No antennas of any kind. The condo council had at least one member that was certain that property values would decline if a ham was allowed to operate from the condo farm. So, I leaned a 20ft aluminum extension ladder against the house and ran a wire to the radio. It worke quite well with a tuner. The ladder was left leaning against the condo for a bit less than a year before the condo council discovered the ruse. There was a short debate. The council decided that since it had been in operation for a year without any complaints or detrimental effects, it could stay. Good move! I've always maintained that if you give me any old piece of metal almost anywhere, I'd find a way to load it and get on the air! And I've done it time and time again. I did 26 years in the navy and moved around a lot -- quick and simple antennas were a must! I also helped a lot of chums who moved into condos or rest homes get on the air using similar methods. This case now though, is the first time I ever went into a place that seemed impervious to signals. I've often operated from indoors with no problem, and here, the first time I flashed up the receiver, thought it had gone dead -- that's how bad it was. The first thing I did was checked the protective diodes on the antenna connector and as soon as I found them OK, opened the window and strung a short wire outside -- then everything was 5/9 plus! As per another sailor many years ago said, 'I have not yet begun to fight!' Irv VE6BP |
Indoor Counterpoise For Random Wire Antenna
On Sun, 29 Apr 2012 16:24:52 -0600, "Irv Finkleman"
wrote: I have an MFJ-259B -- couldn't live without it, and with all the stuff I gave away this was the one thing that I just couldn't part with. For when you transmit into it by accident... http://802.11junk.com/jeffl/pics/2011-12-03-Storm/ The MJF-259B is similar to the MFJ-269B, except that it lacks the 440MHz section. It's a very handy instrument, but is rather fragile in that the detector diodes are connected directly to the RF connector. One blast of too much RF, too much static electricity, or even too much DC, and the diodes go poof. Good move! I've always maintained that if you give me any old piece of metal almost anywhere, I'd find a way to load it and get on the air! There's also the rain gutters. This case now though, is the first time I ever went into a place that seemed impervious to signals. I've often operated from indoors with no problem, and here, the first time I flashed up the receiver, thought it had gone dead -- that's how bad it was. The first thing I did was checked the protective diodes on the antenna connector and as soon as I found them OK, opened the window and strung a short wire outside -- then everything was 5/9 plus! Welcome to the joys of modern energy efficient construction. The walls are full of aluminum foil backed insulation for both thermal and acoustic insulation. The windows are coated with Low-E Titanium Nitride IR reflective coatings (40 ohms per square), which also blocks RF. The roofing material is carbon doped (instead of asbestos) which absorbs RF. The foundation is concrete, which also absorbs RF. Meanwhile, the proliferation of microprocessors, switching power supplies, and BPL like devices, offers multiple sources of QRN. You had it easy at previous locations. As per another sailor many years ago said, 'I have not yet begun to fight!' Fighting is easy. It's negotiation that drives me nuts. -- Jeff Liebermann 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558 |
Indoor Counterpoise For Random Wire Antenna
Welcome to the joys of modern energy efficient construction. The walls are full of aluminum foil backed insulation for both thermal and acoustic insulation. The windows are coated with Low-E Titanium Nitride IR reflective coatings (40 ohms per square), which also blocks RF. The roofing material is carbon doped (instead of asbestos) which absorbs RF. The foundation is concrete, which also absorbs RF. Meanwhile, the proliferation of microprocessors, switching power supplies, and BPL like devices, offers multiple sources of QRN. You had it easy at previous locations. I kind of fell behind in my knowledge of modern constuction. I lived in my house for 29-3/4 years and even though I did a lot of renos, the infrastruction remained basically the same. It is good though that they are getting smart on energy efficient construction and other things -- hopefully we will leave our kids and grandkids with a world pointed in the right direction. As per another sailor many years ago said, 'I have not yet begun to fight!' Fighting is easy. It's negotiation that drives me nuts. I'm on the air but not sure just how well I am getting out, I don't want to measure it, I don't even care to know since it is a whole different matter on QRP. The proof will be in the pudding -- I may have to wait for good band conditions, but the only valid means of measurement will be the number of QSO's and bands I can work. From those lovely boxes of variable caps and assorted inductors (some roller-inductors) and a cheap 2nd hand 50ua meter I am going to build up an artificial ground which is about as simple a circuit as one can get -- the L&C in series and make a sniffer out of the meter and a diode!. I should have it all going in the next day or two -- as soon as I can get a round tooit. Yes. I admit -- I'm a master of procrastination Well, on with the further adventures of getting on the air to the point of satisfaction. Is that a lot, I ask? Thanks on the tips re the MFJ diodes. I'm aware of them and can test and change them if need be. So far, so good! I guess it wouldn't hurt to have some on hand -- it's pretty inevitable that with the experimentation etc, that I'll be doing some or all will get blown before you can say poof! Do you think that if I were to ask the management here If I could have an aluminum ladder outside my second floor window -- just to easy my mind about the dangers of fire, they might agree? Irv VE6BP -- Jeff Liebermann 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558 |
Indoor Counterpoise For Random Wire Antenna
On Sun, 29 Apr 2012 19:12:01 -0600, "Irv Finkleman"
wrote: It is good though that they are getting smart on energy efficient construction and other things -- hopefully we will leave our kids and grandkids with a world pointed in the right direction. Yep. It's happening, but very slowly and painfully. Ecology is expensive in the short term, but worth the cost and effort. Unfortunately, I've seen some abuse of power precipitated in the name of the environment. Like all good things, environmental correctness does attract a few flies. I'm on the air but not sure just how well I am getting out, I don't want to measure it, I don't even care to know since it is a whole different matter on QRP. Oh rubbish. There are plenty of ways to test your setup that doesn't involve calling CQ and getting a subjective signal report: 1. You can login to one of the remote radios or receivers on the internet, tune to an empty frequency, and listen to yourself. http://beta.remotehams.com http://www.dxzone.com/catalog/Internet_and_Radio/Online_Receivers/ 2. You can join one of the internet QRP clubs. 3. Weak Signal Propagation Reporter Network http://wsprnet.org 4. Reverse Beacon Network: http://www.reversebeacon.net 5. You can listen for beacons to check your receiver and antenna: http://www.ac6v.com/beacons.htm Our local radio club also has a remote HF station controllable over the internet (using HRD) but it's only for club members. From those lovely boxes of variable caps and assorted inductors (some roller-inductors) and a cheap 2nd hand 50ua meter I am going to build up an artificial ground which is about as simple a circuit as one can get -- the L&C in series and make a sniffer out of the meter and a diode!. All an artificial ground does is tune out the ground lead inductance so that it's series resonant at the operating frequency. In effect, you're building a counterpoise. You could user your MFJ-259B or a grid dip meter to resonate the ground lead, and forget about the meter and detector. However, if you must use a meter, I suggest a thermocouple RF ammeter. Getting it to heat up the series resistor at 5 watts might be a challenge, but it can be done. Otherwise, it's a current transfomer, ferrite core, diode detector, and 50ua meter. http://www.w1tag.com/RFA.htm I'm a master of procrastination I have a PHD in procrastination. Never do today what you get someone else to do for you tomorrow. Is that a lot, I ask? Yes, if you try to do it all at once. No, if you take your time, grind the numbers, do a little planning, and invite all your friends to help. Thanks on the tips re the MFJ diodes. I'm aware of them and can test and change them if need be. I could only test the diodes after they were removed. The 50 ohm resistors in the circuit prevented easy checking with an ohms guesser. So far, so good! I guess it wouldn't hurt to have some on hand -- it's pretty inevitable that with the experimentation etc, that I'll be doing some or all will get blown before you can say poof! Yep. My experience is that certain users tend to blow up diodes no matter what they do, while others don't have any problems. I'm sure it's the user, not the analyzer. Possibly static build-up or ungrounded antennas. Dunno. I've been fairly lucky replacing all 4 diodes without needed to calibrate the device. However, if you find the readings off after replacement, see: http://www.w8ji.com/mfj-259b_calibration.htm The procedure took me 2 full days on an MFJ-269B. It went much quicker after I read and followed the instructions. Do you think that if I were to ask the management here If I could have an aluminum ladder outside my second floor window -- just to easy my mind about the dangers of fire, they might agree? No. Someone will probably try to steal the ladder. 20ft ladders are not cheap. I ran two u-bolts through the ladder base, and permanently attached the u-bolts to two foundation blocks with half a bag of concrete mix in the hole. Various attempts were made to steal it, but nobody got very far with 30 kg of buried excess weight attached. The connecting antenna wire also acts as a capacitive alarm when the HF radio is not being used. All this was only possible because each condo had its own private back yard. Another problem with a 2nd floor ladder is that you will be feeding the ladder from the top, rather than from the bottom. That will possibly work, but probably not as good as feeding the ladder from the bottom. -- Jeff Liebermann 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558 |
Indoor Counterpoise For Random Wire Antenna
"Jeff Liebermann" wrote in message ... On Sun, 29 Apr 2012 19:12:01 -0600, "Irv Finkleman" wrote: It is good though that they are getting smart on energy efficient construction and other things -- hopefully we will leave our kids and grandkids with a world pointed in the right direction. (snipped now and again here and there for brevity) I'm on the air but not sure just how well I am getting out, I don't want to measure it, I don't even care to know since it is a whole different matter on QRP. Oh rubbish. There are plenty of ways to test your setup that doesn't involve calling CQ and getting a subjective signal report: 1. You can login to one of the remote radios or receivers on the internet, tune to an empty frequency, and listen to yourself. http://beta.remotehams.com http://www.dxzone.com/catalog/Internet_and_Radio/Online_Receivers/ 2. You can join one of the internet QRP clubs. 3. Weak Signal Propagation Reporter Network http://wsprnet.org 4. Reverse Beacon Network: http://www.reversebeacon.net 5. You can listen for beacons to check your receiver and antenna: http://www.ac6v.com/beacons.htm Our local radio club also has a remote HF station controllable over the internet (using HRD) but it's only for club members. I won't care about subjective reports -- I'll be happy if my few paltry watts that do escape the antenna get me any kind of response. I am aware of the remote receivers but I don't want to get so busy using other things that I won't have time on the air making plain good old fashioned QSOs. I will have a peek at the internet QRP clubs as long as I don't lose on air time going to meetings -- even on-air! From those lovely boxes of variable caps and assorted inductors (some roller-inductors) and a cheap 2nd hand 50ua meter I am going to build up an artificial ground which is about as simple a circuit as one can get -- the L&C in series and make a sniffer out of the meter and a diode!. All an artificial ground does is tune out the ground lead inductance so that it's series resonant at the operating frequency. In effect, you're building a counterpoise. You could user your MFJ-259B or a grid dip meter to resonate the ground lead, and forget about the meter and detector. I considered that. I already have a group of radials of various lengths on the floor -- I tied them together with plastic ties for neatness, but with a ground tuner I only need one which I plan to lay out along the edge of the carpet -- that should make a neater job and if I can tuck most of it under the baseboards it will not frighten the houskeeper. However, if you must use a meter, I suggest a thermocouple RF ammeter. Getting it to heat up the series resistor at 5 watts might be a challenge, but it can be done. Otherwise, it's a current transfomer, ferrite core, diode detector, and 50ua meter. http://www.w1tag.com/RFA.htm A simple diode detector may be enough, but if necessary I'll have to line up ferrite core and get complicated. I'm a master of procrastination I have a PHD in procrastination. Never do today what you get someone else to do for you tomorrow. I was always good at procrastination however I did not consider the part of having someone else do the work -- that's probably why you have the PhD and I don't!! Is that a lot, I ask? Yes, if you try to do it all at once. No, if you take your time, grind the numbers, do a little planning, and invite all your friends to help. That's the nice thing about being a retired senior -- I can take all the time I want, and as you've seen in this thread, I'm doing a lot of planning, and if necessary there I've got lots of ham chums who will be anxious to lend a hand just to get in here and see what I'm up to. Thanks on the tips re the MFJ diodes. I'm aware of them and can test and change them if need be. I have the W8JI procedure tucked away in a safe place on my computer where I may never find it again, Thank heaven for good search tools. I could only test the diodes after they were removed. The 50 ohm resistors in the circuit prevented easy checking with an ohms guesser. I never considered that -- oh well, it should only take a jiffy to pop the diodes out although there is always Murphy to take into account. So far, so good! I guess it wouldn't hurt to have some on hand -- it's pretty inevitable that with the experimentation etc, that I'll be doing some or all will get blown before you can say poof! Yep. My experience is that certain users tend to blow up diodes no matter what they do, while others don't have any problems. I'm sure it's the user, not the analyzer. Possibly static build-up or ungrounded antennas. Dunno. I've been fairly lucky replacing all 4 diodes without needed to calibrate the device. However, if you find the readings off after replacement, see: http://www.w8ji.com/mfj-259b_calibration.htm The procedure took me 2 full days on an MFJ-269B. It went much quicker after I read and followed the instructions. Now there's a very unhamlike suggestion -- wouldn't stopping to read and follow the instructions severely slow down the calibration procedure? Do you think that if I were to ask the management here If I could have an aluminum ladder outside my second floor window -- just to easy my mind about the dangers of fire, they might agree? No. Someone will probably try to steal the ladder. 20ft ladders are not cheap. I ran two u-bolts through the ladder base, and permanently attached the u-bolts to two foundation blocks with half a bag of concrete mix in the hole. Various attempts were made to steal it, but nobody got very far with 30 kg of buried excess weight attached. The connecting antenna wire also acts as a capacitive alarm when the HF radio is not being used. All this was only possible because each condo had its own private back yard. I've considered all the security precautions you took with the ladder. At the moment I'm considering how to rotate it, and wondering if I couldn't use a wooden ladder with lots of wire stapled to it in a multiband Hentenna configuration! I guess I may have to rethink it and take it one step at a time! Now, I have to consider which rotor. Do you by chance know offhand the wind load of a 20 ft Al ladder? How about a folding ladder for the sake of extra length? Another problem with a 2nd floor ladder is that you will be feeding the ladder from the top, rather than from the bottom. That will possibly work, but probably not as good as feeding the ladder from the bottom. I'll use double sideband so that it won't matter which end of the ladder I feed it from! Cheers, this is fun! Irv VE6BP |
Indoor Counterpoise For Random Wire Antenna
On Sun, 29 Apr 2012 22:59:25 -0600, "Irv Finkleman"
wrote: I never considered that -- oh well, it should only take a jiffy to pop the diodes out although there is always Murphy to take into account. Umm... the diodes don't quite pop out in a jiffy. You must first tear apart the instrument just to get to the diodes. They're tiny little devils, best handled with stainless SMD tweezers. http://802.11junk.com/jeffl/crud/mfj-269b-diodes.jpg They're the 4 black things labeled "COB". If you order some from Digikey or Mouser, be sure to get plenty of spares. I dropped two on my workbench, where they promptly disappeared. -- Jeff Liebermann 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558 |
Indoor Counterpoise For Random Wire Antenna
On Sun, 29 Apr 2012 22:59:25 -0600, "Irv Finkleman"
wrote: I have the W8JI procedure tucked away in a safe place on my computer where I may never find it again, Thank heaven for good search tools. Try "Search Everything". http://www.voidtools.com If you can remember parts of the file name or folder, it will find it instantly. The procedure took me 2 full days on an MFJ-269B. It went much quicker after I read and followed the instructions. Now there's a very unhamlike suggestion -- wouldn't stopping to read and follow the instructions severely slow down the calibration procedure? I consider reading instructions a sign of weakness, especially when customers are watching. When they see me reading the docs, they usually ask if I know what I'm doing, or if I had done this before. In order to maintain my image, I try not to be seen reading the docs. However, I do read the instructions..... after I'm done, and only to see if I missed anything. On the MFJ-269B calibration, and after starting over for the 3rd or 4th time, I decided that it might be useful to just do it right, reading from beginning to end. At the moment I'm considering how to rotate it, and wondering if I couldn't use a wooden ladder with lots of wire stapled to it in a multiband Hentenna configuration! I guess I may have to rethink it and take it one step at a time! Now, I have to consider which rotor. Do you by chance know offhand the wind load of a 20 ft Al ladder? No, but I could probably calculate the wind load if I had the dimensions. Ice load will probably be the worst case. However, I don't think a rotatable ladder would be a good or useful idea. The ladder is mostly vertical, and rotation of a vertical doesn't do anything useful. I suggest you leave it leaning against the building and live with whatever that produces. Incidentally, if there's anyone living directly below you, they may object to having the ladder block their view. My friend's ladder antenna was possible because his condo was a townhouse arrangement, where he owned both the lower and upper windows. How about a folding ladder for the sake of extra length? The 20ft ladder I used was a 2 section telescoping ladder. I had the not so bright idea of changing the length in order to tune the antenna to something near 1/4 wavelength. I also experimented with an insulating sleeve between the two sections in an attempt to make a vertical dipole. Both proved of dubious value as the best results were from using the full length ladder and an antenna tuner. I'm not sure what a folding ladder will do except to add weight and attract unwanted attention. I just gave away two steel folding ladders. They weighed far too much but were admittedly quite useful. I'll use double sideband so that it won't matter which end of the ladder I feed it from! Be sure to tilt your radio vertically to match the antenna polarization. Cheers, this is fun! If it were easy, it would not be fun. -- Jeff Liebermann 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558 |
Indoor Counterpoise For Random Wire Antenna
"Jeff Liebermann" wrote in message ... On Sun, 29 Apr 2012 22:59:25 -0600, "Irv Finkleman" wrote: I never considered that -- oh well, it should only take a jiffy to pop the diodes out although there is always Murphy to take into account. Umm... the diodes don't quite pop out in a jiffy. You must first tear apart the instrument just to get to the diodes. They're tiny little devils, best handled with stainless SMD tweezers. http://802.11junk.com/jeffl/crud/mfj-269b-diodes.jpg They're the 4 black things labeled "COB". If you order some from Digikey or Mouser, be sure to get plenty of spares. I dropped two on my workbench, where they promptly disappeared. After I retired from the Navy I worked for Sony as a tech for 14 years and became pretty handy with SMD. When I retired from Sony I kept my tools which included a headband magnifier and a few different tweezers only one of which I consistently used. I do recall losing one or two of the smaller SMD components but I eventually learned to take precautions to avoid doing so.. With respect to taking things apart and then getting them back together again I have to brag about my abilities. When I had my first interview with Sony the asked me how much of the work I considered electronic and how much was mechanical. I estimated 90 percent mechanical (getting the old part out and putting the new part in and then the unit back together). I know now that it is more like 99.9%. Oh well, I guess I'll just have to try and not blow the diodes even though we both believe it will be inevitable! Irv VE6BP |
Indoor Counterpoise For Random Wire Antenna
On Mon, 30 Apr 2012 09:06:53 -0600, "Irv Finkleman"
wrote: After I retired from the Navy I worked for Sony as a tech for 14 years and became pretty handy with SMD. I worked for Sony/Superscope in Sunland-Tujunga California for a short while in the mid 1960's. Too far to drive from where I was living and going to skool. When I retired from Sony I kept my tools which included a headband magnifier and a few different tweezers only one of which I consistently used. Does your former boss know about this? Is there a reward for turning you in? If you're going to pilfer the tools, at least take something expensive. I left one company with my junk parts box, my collection of component samples, a DVM, and my favorite screwdriver. I probably could have taken a load of test equipment, as nobody seemed to care. I figured the dumpster would be full of junk after the layoff/purge. I was right and collected quite a pile of goodies from the dumpster. I also suspected that my project notes would be thrown away, so I grabbed those. Many years later, the company raised one project from the dead and called asking if I had any history on the project. Like a fool, I just gave it to them, instead of demanding payment. Like all products, my ancient products eventually hit the surplus market. Like all good surplus equipment, there were no manuals to be found. So, like a complete fool, I scanned the manuals and posted them to my web pile. I now waste far too much time answering questions and helping with repairs. Lesson learned: Products tend to rise from the dead and will haunt you like zombies. I do recall losing one or two of the smaller SMD components but I eventually learned to take precautions to avoid doing so.. My standard precaution is to buy extra parts. The parts are cheap. My time is not. I use metal egg trays for parts storage. However, I also tend to tip those over or bury them in junk. My latest trick is using semi-sticky window shelf paper to hold parts. That works great after I remove the flies, bugs, and glue eating banana slugs. With respect to taking things apart and then getting them back together again I have to brag about my abilities. When I had my first interview with Sony the asked me how much of the work I considered electronic and how much was mechanical. I estimated 90 percent mechanical (getting the old part out and putting the new part in and then the unit back together). I know now that it is more like 99.9%. Agreed. When I started in engineering, it was 99.9% engineering and 0.01% politics. 15 years or so later, it was 99.9% politics and 0.01% engineering. Productivity was about the same in both cases. Now that I'm officially in the repair biz, my guess is about 33% repair, 33% paper shuffling, and 33% customer ego support. One nice thing about ham radio is that if I announce that I'm working on a project, and I procrastinate enough, then one of the local hams will eventually do it for me. See Tom Sawyer white washing a fence for details on how it works. Oh well, I guess I'll just have to try and not blow the diodes even though we both believe it will be inevitable! Not really. As I previously ranted, only certain people seem to blow up the diodes. If you haven't blown any diodes by now, you're probably safe. Just don't loan it to any of your friends, especially on Field Day[1]. What seems to kill the analyzers is the act of plugging in and unplugging a PL-259 to the unit. The PL-259 is unique in that the center pin makes contact before the ground. This is what's commonly known as a lousy idea. If you've built up a static charge with your clothes and shoes, and are holding the shield, you'll discharge yourself through the center pin and directly into the diodes. That's my guess(tm) as to what's happening. I now make it a habit of touching the center pin to case ground, before plugging in. No clue if it helps, but it seems like a good idea. The N connector on the MFJ-269B should not have this problem, but they seem to blow up anyway, probably due to a different failure mechanism. Irv VE6BP [1] Hint: Measure the DC voltage on the traditional Field Day balloon supported long wire antenna, especially if there's some wind. If the DVM doesn't explode, you're still not safe. -- Jeff Liebermann 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558 |
Indoor Counterpoise For Random Wire Antenna
When I retired from Sony I kept my tools which included a headband magnifier and a few different tweezers only one of which I consistently used. Does your former boss know about this? Is there a reward for turning you in? If you're going to pilfer the tools, at least take something expensive. I actually asked permission. It is because I have always been fair and honest that I am known as 'Fairly Honest Irv'. I couldn't take any test equipment or the Fluke 77, but I luckily picked one up for $25 at a flea market. My standard precaution is to buy extra parts. The parts are cheap. My time is not. I use metal egg trays for parts storage. However, I also tend to tip those over or bury them in junk. My latest trick is using semi-sticky window shelf paper to hold parts. That works great after I remove the flies, bugs, and glue eating banana slugs. I use the sticky tape method too! Now If I could just find where it put it! Agreed. When I started in engineering, it was 99.9% engineering and 0.01% politics. 15 years or so later, it was 99.9% politics and 0.01% engineering. Productivity was about the same in both cases. Now that I'm officially in the repair biz, my guess is about 33% repair, 33% paper shuffling, and 33% customer ego support. GRIN One nice thing about ham radio is that if I announce that I'm working on a project, and I procrastinate enough, then one of the local hams will eventually do it for me. See Tom Sawyer white washing a fence for details on how it works. That's pretty common here in town. If an antenna is being raised, even digging the hole for a tower, there is usually a good turnout of the younger more able hams. Some say that hams aren't like they used to be, but for the most part I find them a good crowd. Not really. As I previously ranted, only certain people seem to blow up the diodes. If you haven't blown any diodes by now, you're probably safe. Just don't loan it to any of your friends, especially on Field Day[1]. What seems to kill the analyzers is the act of plugging in and unplugging a PL-259 to the unit. The PL-259 is unique in that the center pin makes contact before the ground. This is what's commonly known as a lousy idea. If you've built up a static charge with your clothes and shoes, and are holding the shield, you'll discharge yourself through the center pin and directly into the diodes. That's my guess(tm) as to what's happening. I now make it a habit of touching the center pin to case ground, before plugging in. No clue if it helps, but it seems like a good idea. The N connector on the MFJ-269B should not have this problem, but they seem to blow up anyway, probably due to a different failure mechanism. I wouldn't even loan it to my mother, had she been a ham, but I've carried it to a few hams but did the testing myself. It cost more than most of my rigs! Irv VE6BP [1] Hint: Measure the DC voltage on the traditional Field Day balloon supported long wire antenna, especially if there's some wind. If the DVM doesn't explode, you're still not safe. When I was still a pretty green ham, I heard a snapping noise one night -- found it coming from the tuner! Wouldn't touch it till it stopped! I eventually learned about wind static. |
Indoor Counterpoise For Random Wire Antenna
On Mon, 30 Apr 2012 12:32:09 -0600, "Irv Finkleman"
wrote: I actually asked permission. It is because I have always been fair and honest that I am known as 'Fairly Honest Irv'. If caught, I usually ask for forgiveness. It's easier than asking for permission. I've gone by various names, none of which involve being honest. I couldn't take any test equipment or the Fluke 77, but I luckily picked one up for $25 at a flea market. I liberated my Fluke 75. Great DVM. That's pretty common here in town. If an antenna is being raised, even digging the hole for a tower, there is usually a good turnout of the younger more able hams. Some say that hams aren't like they used to be, but for the most part I find them a good crowd. The local help is mixed. In general, a work crew can be organized, but it's not like it was 20-30 years ago. The problem is that the bulk of the ham population is aging and thus unable to do many of the dumb and dangerous things that are considered normal for younger hams. I gave up tower climbing at age=50 and steep roof climbing at age=60. If I can't find a way to not trip over the coax cables and walk into the guy wires on my roof, I may need to give up flat roofs. When dealing with 100ft+ trees, I hire a professional tree climber. I also have him prune the tree at the same time. I have two stainless sailing blocks (pulleys) up in the trees for raising wire antennas. Unfortunately, the rope used to raise the antenna rotted and broke. If I can find an excuse, I'll hire a tree climber to replace the ropes. I wouldn't even loan it to my mother, had she been a ham, but I've carried it to a few hams but did the testing myself. It cost more than most of my rigs! The MFJ-259B sells for $240 from various dealers. Your FT-817ND sells new for about $600. Either you overpaid, or you're getting a sweet deal on the radios. -- Jeff Liebermann 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558 |
Indoor Counterpoise For Random Wire Antenna
"Jeff Liebermann" wrote in message ... On Mon, 30 Apr 2012 12:32:09 -0600, "Irv Finkleman" wrote: I wouldn't even loan it to my mother, had she been a ham, but I've carried it to a few hams but did the testing myself. It cost more than most of my rigs! The MFJ-259B sells for $240 from various dealers. Your FT-817ND sells new for about $600. Either you overpaid, or you're getting a sweet deal on the radios. The FT-817ND is my first store bought rig. Prior to my downfall from good health, I always had either surplus which I'd converted, or old rigs off the local Swap 'N Shops which needed repair. As much as I say I'm going QRP, if I can pick up an old Kenwood tube-job I think I'll give it a go! Unless I have a number of knobs and switches to play with I sense a loss of control running the new stuff. A TS-820 or 830 would be great -- I had an 820 that really performed for me for a long time -- I gave it away when I went in the hospital. I repaired a lot of Kenwoods Swans and Yaesu's (not to mention other makes) for old-timers and really enjoyed fixing them. I repaired a lot of the newer solid-state rigs as well, but preferred the old classics. I have a lead on the 820 I gave away, and may end up getting it back. When I got it, it didn't have the DC converter or the digital display but I managed to find them on a cannibalized unit. It even had the CW filter.. The only other thing I'd need would be a keyer for a beautiful mint Bencher key I picked up from an estate sale. The beauty of the Kenwoods is that as long as 6146s and 12BY7s are available I know I can keep them running. Irv VE6BP |
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