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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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