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New LongWire Antenna - What Type Wire?
As my existing fence is falling down and I have saved the 3K to replace
it it's also time for a new antenna. What type of wire would be best? My existing antenna is around the fence about 8' in the area and the area is shaped like [ with the long side running North/South. |
New LongWire Antenna - What Type Wire?
On Sat, 11 Mar 2006 10:09:52 -0600, James Douglas
wrote: As my existing fence is falling down and I have saved the 3K to replace it it's also time for a new antenna. What type of wire would be best? My existing antenna is around the fence about 8' in the area and the area is shaped like [ with the long side running North/South. I like 22g Stranded Tinned Teflon Coated |
New LongWire Antenna - What Type Wire?
James Douglas wrote: As my existing fence is falling down and I have saved the 3K to replace it it's also time for a new antenna. What type of wire would be best? My existing antenna is around the fence about 8' in the area and the area is shaped like [ with the long side running North/South. - I prefer stranded insulated Wire; either solder the joints or silicone glue them; with supports frequent enough so it won't blow down ( in normal winds) and is " Ice Storm" proof.. Winding the insulated wire around a 3/4 inch nylon rope might also do the trick Multiple antennas are another idea.. - More ideas at the link below . . . http://www.hard-core-dx.com/nordicdx...ire/index.html |
New LongWire Antenna - What Type Wire?
Bull**** David!
Buy yourself some WIRE! Get a roll of #12 teflon coated that will last for years and not break if your neihbor farts in the same direction its hanging....#12 stranded will take a lot of bending and flexing with the wind. Believe it or not a #12 wire antenna is easier to tune and actually picks up better than the hair sized crap that reminds David of his penis diameter. Plus #12 is easier to solder on !.... At 30$ to 40$ a 500 foot roll its a great investment! It comes in green...brown...white...grey...red...blue...orange ect. so you can hide it no matter what. I've done the #18 and # 22 Mistakes before.......Never again! I can break the stuff by stretching it with my bare hands. If your not on lifetime public assistance like David?....go for the good stuff! "David" wrote in message ... On Sat, 11 Mar 2006 10:09:52 -0600, James Douglas wrote: As my existing fence is falling down and I have saved the 3K to replace it it's also time for a new antenna. What type of wire would be best? My existing antenna is around the fence about 8' in the area and the area is shaped like [ with the long side running North/South. I like 22g Stranded Tinned Teflon Coated |
New LongWire Antenna - What Type Wire?
On Sat, 11 Mar 2006 10:09:52 -0600, James Douglas
wrote: As my existing fence is falling down and I have saved the 3K to replace it it's also time for a new antenna. What type of wire would be best? My existing antenna is around the fence about 8' in the area and the area is shaped like [ with the long side running North/South. A 500-foot roll of #14 or #16 stranded insulated in your choice of designer hues is available from Lowe's or Home Depot, about $25 if you buy the whole roll. bob k5qwg |
New LongWire Antenna - What Type Wire?
On Sat, 11 Mar 2006 11:53:41 -0500, "markey"
wrote: Bull**** David! Buy yourself some WIRE! Get a roll of #12 teflon coated that will last for years and not break if your neihbor farts in the same direction its hanging....#12 stranded will take a lot of bending and flexing with the wind. Believe it or not a #12 wire antenna is easier to tune and actually picks up better than the hair sized crap that reminds David of his penis diameter. Plus #12 is easier to solder on !.... At 30$ to 40$ a 500 foot roll its a great investment! It comes in green...brown...white...grey...red...blue...orang e ect. so you can hide it no matter what. I've done the #18 and # 22 Mistakes before.......Never again! I can break the stuff by stretching it with my bare hands. If your not on lifetime public assistance like David?....go for the good stuff! Whilst in principle a broader cross section results in lower Q, the diameters as a fraction of wavelength are virtually identical, Asshole. And a $500 foot roll of TFE coated wire costs way more than 30 or 40 clams. |
New LongWire Antenna - What Type Wire?
Oh Pleeeze disease!
I paid 36.50 for my last roll almost a month ago.You must be shopping at some democrap store?? And as far as diameters and fractions....you can tell a difference on same length antenna's in recieving side by side ...a BIG NOTICABLE DIFFERENCE! Go pick up your food stamps and trade em in for another rock of crack. "David" wrote in message ... On Sat, 11 Mar 2006 11:53:41 -0500, "markey" wrote: Bull**** David! Buy yourself some WIRE! Get a roll of #12 teflon coated that will last for years and not break if your neihbor farts in the same direction its hanging....#12 stranded will take a lot of bending and flexing with the wind. Believe it or not a #12 wire antenna is easier to tune and actually picks up better than the hair sized crap that reminds David of his penis diameter. Plus #12 is easier to solder on !.... At 30$ to 40$ a 500 foot roll its a great investment! It comes in green...brown...white...grey...red...blue...oran ge ect. so you can hide it no matter what. I've done the #18 and # 22 Mistakes before.......Never again! I can break the stuff by stretching it with my bare hands. If your not on lifetime public assistance like David?....go for the good stuff! Whilst in principle a broader cross section results in lower Q, the diameters as a fraction of wavelength are virtually identical, Asshole. And a $500 foot roll of TFE coated wire costs way more than 30 or 40 clams. |
New LongWire Antenna - What Type Wire?
On Sat, 11 Mar 2006 12:34:13 -0500, "markey"
wrote: Oh Pleeeze disease! I paid 36.50 for my last roll almost a month ago.You must be shopping at some democrap store?? And as far as diameters and fractions....you can tell a difference on same length antenna's in recieving side by side ...a BIG NOTICABLE DIFFERENCE! Go pick up your food stamps and trade em in for another rock of crack. Mmmm...Cra-a-a-a-ck....[drool] 2222/19UL Hook-Up Wire 22 AWG (19/34) 100' Spool $27.13 500' $135.65 http://www.weicowire.com/CartView.asp |
New LongWire Antenna - What Type Wire?
Now is your chance to get a Wellbrook.
James Douglas wrote: As my existing fence is falling down and I have saved the 3K to replace it it's also time for a new antenna. What type of wire would be best? My existing antenna is around the fence about 8' in the area and the area is shaped like [ with the long side running North/South. |
New LongWire Antenna - What Type Wire?
On Sat, 11 Mar 2006 12:53:02 -0500, "markey"
wrote: Oh and by the way ****bird? Wire from Home Depot and Lowes are also TFE OR PVC coated! How bout I send you dozens of rolls of lets say ...#10 for 400$ each! You dip**** Damn, Girl. Switch to decaf. You were saying 12 g was $40 for 500'. |
New LongWire Antenna - What Type Wire?
On Sat, 11 Mar 2006 12:55:16 -0500, "markey"
wrote: Hey David... http://cgi.ebay.com/Teflon-Wire-Silv...cm dZViewItem DUUUUUHHHHHHHHHH!!!!!! Ebay **** is stolen half the time. I support people I can look in the eye. |
New LongWire Antenna - What Type Wire?
I like insulated multistrand bell wire. You can pay fro fancier wire, but
sooner or later, after a few years, the wire will get rusty and corroded and it will need to be replaced. Any hardware store or grange should have suitable wire. I'm not sure how long you want it to be, but make sure you have a static-lightening arrestor connected to it to protect your system s. All life all holiness come from you O Lord http://home.earthlink.net/~damienmj/index.htm http://home.earthlink.net/~damianomj/swallowindex.htm "James Douglas" wrote in message . .. As my existing fence is falling down and I have saved the 3K to replace it it's also time for a new antenna. What type of wire would be best? My existing antenna is around the fence about 8' in the area and the area is shaped like [ with the long side running North/South. |
New LongWire Antenna - What Type Wire?
Like your dealer?
I'll bet your eyes are yellow. |
New LongWire Antenna - What Type Wire?
On Sat, 11 Mar 2006 18:19:44 GMT, David wrote:
On Sat, 11 Mar 2006 12:53:02 -0500, "markey" wrote: Oh and by the way ****bird? Wire from Home Depot and Lowes are also TFE OR PVC coated! How bout I send you dozens of rolls of lets say ...#10 for 400$ each! You dip**** Damn, Girl. Switch to decaf. You were saying 12 g was $40 for 500'. I paid $25 at Lowe's Home Improvement for a 500' roll of 12g solid insulated -- course, that was a year or two ago. Might be $10-$15 higher now. The specialized wire places have nice wire -- and I've bought my share of it -- but basic copper is pretty cheap at the big-box stores. bob k5qwg |
New LongWire Antenna - What Type Wire?
On Sat, 11 Mar 2006 19:18:04 GMT, Bob Miller
wrote: On Sat, 11 Mar 2006 18:19:44 GMT, David wrote: On Sat, 11 Mar 2006 12:53:02 -0500, "markey" wrote: Oh and by the way ****bird? Wire from Home Depot and Lowes are also TFE OR PVC coated! How bout I send you dozens of rolls of lets say ...#10 for 400$ each! You dip**** Damn, Girl. Switch to decaf. You were saying 12 g was $40 for 500'. I paid $25 at Lowe's Home Improvement for a 500' roll of 12g solid insulated -- course, that was a year or two ago. Might be $10-$15 higher now. The specialized wire places have nice wire -- and I've bought my share of it -- but basic copper is pretty cheap at the big-box stores. bob k5qwg Stranded, Tinned, Teflon. But, that's not important. Typical nut-job drivin into the ditch. |
New LongWire Antenna - What Type Wire?
On 11 Mar 2006 11:11:11 -0800, "Steve"
wrote: Like your dealer? I'll bet your eyes are yellow. Dude. I never got anything resembling jaundice. Asymtomatic. A $9,600 in and out mind ****. Nothing more. In fact, you are by far the most annoying aspect of the whole deal. You do realize that because of this you're going to get some karma back... |
New LongWire Antenna - What Type Wire?
On Sat, 11 Mar 2006 19:07:54 GMT, "Verstaldin"
wrote: I like insulated multistrand bell wire. You can pay fro fancier wire, but sooner or later, after a few years, the wire will get rusty and corroded and it will need to be replaced. Any hardware store or grange should have suitable wire. I'm not sure how long you want it to be, but make sure you have a static-lightening arrestor connected to it to protect your system s. All life all holiness come from you O Lord Thanks. I need all the holinesses I can gets. That's why I use the tinned stuff for contact antennas. For pole and insulator antennas I have this stuff from Home Depot called chandelier wire, whic is about 20 g twisted copper. It turns green but doesn't stretch or anything. That's what my 50 foot wire is. Between 2 egg insulators driving a Palomar MLB. I've also had excellent results with solid steel wire, which is $4 for 120 feet. |
New LongWire Antenna - What Type Wire?
In article ,
James Douglas wrote: As my existing fence is falling down and I have saved the 3K to replace it it's also time for a new antenna. What type of wire would be best? My existing antenna is around the fence about 8' in the area and the area is shaped like [ with the long side running North/South. Considering 1. Price 2. Conductor performance. 3. Insulation longevity 1. Discount warehouse home improvement hardware stores. 2. If you were to hang it up on insulators where the wire would have to support its own weight I would give a different answer but you indicate that the new fence will support it so best and cheapest would be solid copper and large diameter. The RF current at medium wave and short wave has a tendency to travel on the exterior of the wire so the resistance to RF current flow is much higher than it is for DC, which tends to use more of the wires cross-sectional area. This Rf effect is know as the skin effect so since the RF current only travels in the "skin" of the wire a larger diameter for a long stretch provides a helpful improvement in performance. How big to go in diameter? Well bigger means larger circumference. According to this web page calculator 15 MHz has a rounded skin depth of 0.000662 inch. That's a pretty thin layer so a step in wire size must mean a significant drop in RF resistance per foot. I would go with the largest wire size available for a reasonable price. Something in the #6, 8 or 10 size would be a good bet. 3. Must withstand the sun and weather effects. Teflon coated is the same color of the fence would be a good choice. -- Telamon Ventura, California |
New LongWire Antenna - What Type Wire?
On Sat, 11 Mar 2006 21:31:41 GMT, Telamon
wrote: In article , James Douglas wrote: As my existing fence is falling down and I have saved the 3K to replace it it's also time for a new antenna. What type of wire would be best? My existing antenna is around the fence about 8' in the area and the area is shaped like [ with the long side running North/South. Considering 1. Price 2. Conductor performance. 3. Insulation longevity best and cheapest would be solid copper and large diameter. The RF current at medium wave and short wave has a tendency to travel on the exterior of the wire so the resistance to RF current flow is much higher than it is for DC, which tends to use more of the wires cross-sectional area. This Rf effect is know as the skin effect so since the RF current only travels in the "skin" of the wire a larger diameter for a long stretch provides a helpful improvement in performance. How big to go in diameter? Well bigger means larger circumference. According to this web page calculator 15 MHz has a rounded skin depth of 0.000662 inch. That's a pretty thin layer so a step in wire size must mean a significant drop in RF resistance per foot. I would go with the largest wire size available for a reasonable price. Something in the #6, 8 or 10 size would be a good bet. ??? If ''skin effect'' is a consideration you want stranded, not solid. But for receiving it's not a factor. |
New LongWire Antenna - What Type Wire?
James Douglas wrote:
As my existing fence is falling down and I have saved the 3K to replace it it's also time for a new antenna. What type of wire would be best? My existing antenna is around the fence about 8' in the area and the area is shaped like [ with the long side running North/South. I ended up getting 500' of #14 stranded copper, with 15mils insulation for $28.00, they wanted $32.00 for 200' taken from the large spool? WTF? Now I may extend the antenna to include a piece that runs across the top of the roof, which on my house is about 30' up in the air! Would that be good or bad, again I have 150' around the fence that runs in the shape of a C, what if I added a "extender" across the roof vent and ran a wire down the to main antenna? I have heard that "higher is better" I am also thinking about adding a two foot extension to the fence posts so that I can get the antenna up a little higher but am wondering what the neighbors are going to think? I do have a balun from Erickson Enginering, which seems to help so far although conditions have not been favorable here lately, and also have 8' copper rod pounded into the ground. |
New LongWire Antenna - What Type Wire?
On Sat, 11 Mar 2006 17:34:13 -0600, James Douglas
wrote: Now I may extend the antenna to include a piece that runs across the top of the roof, which on my house is about 30' up in the air! Would that be good or bad, again I have 150' around the fence that runs in the shape of a C, what if I added a "extender" across the roof vent and ran a wire down the to main antenna? I have heard that "higher is better" I am also thinking about adding a two foot extension to the fence posts so that I can get the antenna up a little higher but am wondering what the neighbors are going to think? I do have a balun from Erickson Enginering, which seems to help so far although conditions have not been favorable here lately, and also have 8' copper rod pounded into the ground. Doubling back in the same plane is probably counterproductive. I'd get as big an ''L'' shaped configuration as I could. I'd also keep the antenna away from the house as it probably has lots of noise sources. Use the ''BalUn'' to match the wire to some co-ax to get the signal into your house from a safe distance away. http://www.hard-core-dx.com/nordicdx...ed/balun3.html The higher the better. (That's for Steve!) |
New LongWire Antenna - What Type Wire?
On Sat, 11 Mar 2006 17:34:13 -0600, James Douglas
wrote: James Douglas wrote: As my existing fence is falling down and I have saved the 3K to replace it it's also time for a new antenna. What type of wire would be best? My existing antenna is around the fence about 8' in the area and the area is shaped like [ with the long side running North/South. I ended up getting 500' of #14 stranded copper, with 15mils insulation for $28.00, they wanted $32.00 for 200' taken from the large spool? WTF? Now I may extend the antenna to include a piece that runs across the top of the roof, which on my house is about 30' up in the air! Would that be good or bad, again I have 150' around the fence that runs in the shape of a C, what if I added a "extender" across the roof vent and ran a wire down the to main antenna? I have heard that "higher is better" You might run the extension, and clip it to your regular fence antenna with an alligator clip -- have someone attach and unattach it out in the yard while you listen to signals. That way, you can see if it improves reception or not. I am also thinking about adding a two foot extension to the fence posts so that I can get the antenna up a little higher but am wondering what the neighbors are going to think? Just tell them you wanted a higher fence :-) Bob k5qwg I do have a balun from Erickson Enginering, which seems to help so far although conditions have not been favorable here lately, and also have 8' copper rod pounded into the ground. |
New LongWire Antenna - What Type Wire?
In article ,
James Douglas wrote: James Douglas wrote: As my existing fence is falling down and I have saved the 3K to replace it it's also time for a new antenna. What type of wire would be best? My existing antenna is around the fence about 8' in the area and the area is shaped like [ with the long side running North/South. I ended up getting 500' of #14 stranded copper, with 15mils insulation for $28.00, they wanted $32.00 for 200' taken from the large spool? WTF? Now I may extend the antenna to include a piece that runs across the top of the roof, which on my house is about 30' up in the air! Would that be good or bad, again I have 150' around the fence that runs in the shape of a C, what if I added a "extender" across the roof vent and ran a wire down the to main antenna? I have heard that "higher is better" Yes higher is better but you will want to keep the antenna away from your electrically noisy house so I advise against this. I am also thinking about adding a two foot extension to the fence posts so that I can get the antenna up a little higher but am wondering what the neighbors are going to think? This will not be worth the trouble. You would need to move it more like 10 feet to make a difference. I do have a balun from Erickson Enginering, which seems to help so far although conditions have not been favorable here lately, and also have 8' copper rod pounded into the ground. The UNUN is good for random/long wire use. -- Telamon Ventura, California |
New LongWire Antenna - What Type Wire?
David wrote:
I've also had excellent results with solid steel wire, which is $4 for 120 feet. I used plastic coated clothesline wire for years. It's stranded steel and is super strong. The ends were over a hundred feet apart and it was stretched pretty tight. Never any sagging due to ice. A split bolt on each end held it around the insulators. The cast from Alfred Hitchcock's 'The Birds' never showed, so I can't comment on hundreds of birds perching on it. mike |
Something Different - On-the-Fence Loop Antenna for the Shortwave Listener (SWL)
JD,
Something Different - - - On-the-Fence Loop Antenna for the Shortwave Listener (SWL) You should first install an 8-Ft Ground Rod at the Foot (Base) of the new Fence. Note - This will be the Starting and Ending Point for your Wire Antenna Element + The Mounting Place for your Matching Transformer { A Balun = Loop-to-Coax } + The Connecting Point for your Coax Cable. Start by running the Wire Antenna Element out along the Bottom of the Fence to your Far-Point. Then a short Wire Antenna Element Leg-Up to the Top of the Fence. Next run the Wire Antenna Element back along the Top of the Fence to your Starting-Point. Finally a a short Wire Antenna Element Down-Leg to the Bottom of the Fence. Mount your Matching Transformer to the Ground Rod Connect your Coax Cable to the Matching Transformer. Connect your Two Wire Antenna Element Ends to the Matching Transformer. You now have an On-the-Fence Loop Antenna [ Bent-Around-the-Fence ] FWIW - Two On-the-Fence Loop Antennas One Rigged on the Fence along one Side of the Yard One Rigged on the Fence along the Back of the Yard Set at 90 Degress and being about 8-ft apart at their Starting Points from a common Corner can give you more Receiving Antenna Options. Note - Separate Ground Rods, Baluns and Coax Cable Feed-in-Lines are recommended if you choose to use two On-the-Fence Loop Antennas. As to the Question of Antenna Wire Size : # 14 AWG Insulated Copper Wire with 19-Strands and using PVC Insulation is cost effective and durable. HomeDepot type - THWN or THHN in 500 Foot Spools TIP - One of the most important details of an On-the-Fence Antenna is the Stand-Offs used to keep the Wire "OFF" the Fence and in the Air. TV "Stand-Offs" with Plastic Insulator Head and 3.5" Wood Screw base hardware. RadioShack Catalog #15-853 (4 Pack) http://www.radioshack.com/product/in...tId=2104003&cp Other On-the-Fence Shortwave Listener (SWL) Antenna ideas http://groups.google.com/group/rec.r...nce+rhf&qt_g=1 hope this helps - iane ~ RHF |
New LongWire Antenna - What Type Wire?
A good source of 'cheap' wire for antennas is any hamfest flea market
(or possibly any flea market as a matter of fact. You can usually find partial or full spools of it piled in boxes and being sold on the cheap. Some companys that use lots of wire will discard it because they no longer need the color codes on its jackets, or they get rid of partial spools once they get down to a certain amount left. Enterprising employees scoop these up and show up at flea markets with it. It may not be exactly what you would purchase if you were buying 'new' but it will work and in most cases will be just a fraction of what you would pay for something new to do the job. Think Spring......antenna construction time is fast aproaching. |
New LongWire Antenna - What Type Wire?
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Something Different - On-the-Fence Loop Antenna for the Shortwave Listener (SWL)
In article .com,
"RHF" wrote: JD, Something Different - - - On-the-Fence Loop Antenna for the Shortwave Listener (SWL) You should first install an 8-Ft Ground Rod at the Foot (Base) of the new Fence. Note - This will be the Starting and Ending Point for your Wire Antenna Element + The Mounting Place for your Matching Transformer { A Balun = Loop-to-Coax } + The Connecting Point for your Coax Cable. Start by running the Wire Antenna Element out along the Bottom of the Fence to your Far-Point. Then a short Wire Antenna Element Leg-Up to the Top of the Fence. Next run the Wire Antenna Element back along the Top of the Fence to your Starting-Point. Finally a a short Wire Antenna Element Down-Leg to the Bottom of the Fence. Mount your Matching Transformer to the Ground Rod Connect your Coax Cable to the Matching Transformer. Connect your Two Wire Antenna Element Ends to the Matching Transformer. You now have an On-the-Fence Loop Antenna [ Bent-Around-the-Fence ] FWIW - Two On-the-Fence Loop Antennas One Rigged on the Fence along one Side of the Yard One Rigged on the Fence along the Back of the Yard Set at 90 Degress and being about 8-ft apart at their Starting Points from a common Corner can give you more Receiving Antenna Options. Note - Separate Ground Rods, Baluns and Coax Cable Feed-in-Lines are recommended if you choose to use two On-the-Fence Loop Antennas. As to the Question of Antenna Wire Size : # 14 AWG Insulated Copper Wire with 19-Strands and using PVC Insulation is cost effective and durable. HomeDepot type - THWN or THHN in 500 Foot Spools TIP - One of the most important details of an On-the-Fence Antenna is the Stand-Offs used to keep the Wire "OFF" the Fence and in the Air. TV "Stand-Offs" with Plastic Insulator Head and 3.5" Wood Screw base hardware. RadioShack Catalog #15-853 (4 Pack) http://www.radioshack.com/product/in...tId=2104003&cp Other On-the-Fence Shortwave Listener (SWL) Antenna ideas http://groups.google.com/group/rec.r...rec.radio.shor twave&q=on-the-fence+rhf&qt_g=1 You describe a close to the ground vertical loop antenna. I expect that at most you would need a 2:1 BALUN but the right answer might be 1:1 with the antenna that close to the ground. The loop is balanced and the coax is not so a BALUN is used here. The loop is a complete antenna unlike the single wire antenna, which still needs a counter poise to complete an RF circuit. The counterpoise or RF return for the signal wire is the ground stake. Generally an optimal situation would be a voltage type transformer as a UNUN so the single wire and ground would be the primary and the coax on the secondary. The single wire is not balanced and neither is the coax so UNUN is used. The loop as a complete antenna does not need the ground as a counterpoise. Useful construction tip would be to bury the coax or if that is not convenient then use clamp on ferrite for a RF choke to stop noise from the radio end of the coax on the outer shield from getting to the loop antenna then into the radio input. The clamp on ferrite would be a current type 1:1 BALUN. -- Telamon Ventura, California |
For Tomorrow - - - The Multi-Element Dipole-on-the-Fence Antenna
In article .com,
"RHF" wrote: For Tomorrow - - - The Multi-Element Dipole-on-the-Fence Antenna * Its 60 to 125 Foot Long * Its Only 4 to 5 Feet High * What Could / Would You Do To Build A Muti-Element Dipole-on-the-Fence Antenna . . . Snip What you are advocating is to tie several elements at the antenna output point together. What can happen is that power from one element can end up going down another element instead of the coax to the radio input. The trick here is to cause one elements to be high impedance when another is at resonance so the relative physical and electrical lengths of the elements must be taken into consideration. -- Telamon Ventura, California |
Something Different - On-the-Fence Loop Antenna for the Shortwave Listener (SWL)
"Telamon" wrote in message .. .. In article .com, "RHF" wrote: JD, Something Different - - - On-the-Fence Loop Antenna for the Shortwave Listener (SWL) You should first install an 8-Ft Ground Rod at the Foot (Base) of the new Fence. Note - This will be the Starting and Ending Point for your Wire Antenna Element + The Mounting Place for your Matching Transformer { A Balun = Loop-to-Coax } + The Connecting Point for your Coax Cable. Start by running the Wire Antenna Element out along the Bottom of the Fence to your Far-Point. Then a short Wire Antenna Element Leg-Up to the Top of the Fence. Next run the Wire Antenna Element back along the Top of the Fence to your Starting-Point. Finally a a short Wire Antenna Element Down-Leg to the Bottom of the Fence. Mount your Matching Transformer to the Ground Rod Connect your Coax Cable to the Matching Transformer. Connect your Two Wire Antenna Element Ends to the Matching Transformer. You now have an On-the-Fence Loop Antenna [ Bent-Around-the-Fence ] FWIW - Two On-the-Fence Loop Antennas One Rigged on the Fence along one Side of the Yard One Rigged on the Fence along the Back of the Yard Set at 90 Degress and being about 8-ft apart at their Starting Points from a common Corner can give you more Receiving Antenna Options. Note - Separate Ground Rods, Baluns and Coax Cable Feed-in-Lines are recommended if you choose to use two On-the-Fence Loop Antennas. Interesting. I have a fence on 2 sides of my property. Previously, I ran a longwire along the two sides (right angle). The end closer to my house was fed directly to my second floor receiver (no transformer or coax). This was used primarily for LW and MW, but served as a secondary antenna for HF (primary is Cliff Donley's 33 foot folded dipole in my roof). I want to replace the flimsy longwire and the 'fence loop' looks promising. Could you (the group) comment on the use of this setup for LW, MW, and HF (each leg is about 85 feet long) with regard to the loops vertical polarization, and whether bending the loop at the right-angle would add or detract from its performance. While you're pondering, how about a vertical 'conical loop'? HankG As to the Question of Antenna Wire Size : # 14 AWG Insulated Copper Wire with 19-Strands and using PVC Insulation is cost effective and durable. HomeDepot type - THWN or THHN in 500 Foot Spools TIP - One of the most important details of an On-the-Fence Antenna is the Stand-Offs used to keep the Wire "OFF" the Fence and in the Air. TV "Stand-Offs" with Plastic Insulator Head and 3.5" Wood Screw base hardware. RadioShack Catalog #15-853 (4 Pack) http://www.radioshack.com/product/in...tId=2104003&cp Other On-the-Fence Shortwave Listener (SWL) Antenna ideas http://groups.google.com/group/rec.r...p=rec.radio.sh or twave&q=on-the-fence+rhf&qt_g=1 You describe a close to the ground vertical loop antenna. I expect that at most you would need a 2:1 BALUN but the right answer might be 1:1 with the antenna that close to the ground. The loop is balanced and the coax is not so a BALUN is used here. The loop is a complete antenna unlike the single wire antenna, which still needs a counter poise to complete an RF circuit. The counterpoise or RF return for the signal wire is the ground stake. Generally an optimal situation would be a voltage type transformer as a UNUN so the single wire and ground would be the primary and the coax on the secondary. The single wire is not balanced and neither is the coax so UNUN is used. The loop as a complete antenna does not need the ground as a counterpoise. Useful construction tip would be to bury the coax or if that is not convenient then use clamp on ferrite for a RF choke to stop noise from the radio end of the coax on the outer shield from getting to the loop antenna then into the radio input. The clamp on ferrite would be a current type 1:1 BALUN. -- Telamon Ventura, California |
Something Different - On-the-Fence Loop Antenna for the Shortwave Listener (SWL)
In article ,
"HankG" wrote: "Telamon" wrote in message .. . In article .com, "RHF" wrote: JD, Something Different - - - On-the-Fence Loop Antenna for the Shortwave Listener (SWL) You should first install an 8-Ft Ground Rod at the Foot (Base) of the new Fence. Note - This will be the Starting and Ending Point for your Wire Antenna Element + The Mounting Place for your Matching Transformer { A Balun = Loop-to-Coax } + The Connecting Point for your Coax Cable. Start by running the Wire Antenna Element out along the Bottom of the Fence to your Far-Point. Then a short Wire Antenna Element Leg-Up to the Top of the Fence. Next run the Wire Antenna Element back along the Top of the Fence to your Starting-Point. Finally a a short Wire Antenna Element Down-Leg to the Bottom of the Fence. Mount your Matching Transformer to the Ground Rod Connect your Coax Cable to the Matching Transformer. Connect your Two Wire Antenna Element Ends to the Matching Transformer. You now have an On-the-Fence Loop Antenna [ Bent-Around-the-Fence ] FWIW - Two On-the-Fence Loop Antennas One Rigged on the Fence along one Side of the Yard One Rigged on the Fence along the Back of the Yard Set at 90 Degress and being about 8-ft apart at their Starting Points from a common Corner can give you more Receiving Antenna Options. Note - Separate Ground Rods, Baluns and Coax Cable Feed-in-Lines are recommended if you choose to use two On-the-Fence Loop Antennas. Interesting. I have a fence on 2 sides of my property. Previously, I ran a longwire along the two sides (right angle). The end closer to my house was fed directly to my second floor receiver (no transformer or coax). This was used primarily for LW and MW, but served as a secondary antenna for HF (primary is Cliff Donley's 33 foot folded dipole in my roof). As to the Question of Antenna Wire Size : # 14 AWG Insulated Copper Wire with 19-Strands and using PVC Insulation is cost effective and durable. HomeDepot type - THWN or THHN in 500 Foot Spools TIP - One of the most important details of an On-the-Fence Antenna is the Stand-Offs used to keep the Wire "OFF" the Fence and in the Air. TV "Stand-Offs" with Plastic Insulator Head and 3.5" Wood Screw base hardware. RadioShack Catalog #15-853 (4 Pack) http://www.radioshack.com/product/in...tId=2104003&cp Other On-the-Fence Shortwave Listener (SWL) Antenna ideas http://groups.google.com/group/rec.r...p=rec.radio.sh or twave&q=on-the-fence+rhf&qt_g=1 You describe a close to the ground vertical loop antenna. I expect that at most you would need a 2:1 BALUN but the right answer might be 1:1 with the antenna that close to the ground. The loop is balanced and the coax is not so a BALUN is used here. The loop is a complete antenna unlike the single wire antenna, which still needs a counter poise to complete an RF circuit. The counterpoise or RF return for the signal wire is the ground stake. Generally an optimal situation would be a voltage type transformer as a UNUN so the single wire and ground would be the primary and the coax on the secondary. The single wire is not balanced and neither is the coax so UNUN is used. The loop as a complete antenna does not need the ground as a counterpoise. Useful construction tip would be to bury the coax or if that is not convenient then use clamp on ferrite for a RF choke to stop noise from the radio end of the coax on the outer shield from getting to the loop antenna then into the radio input. The clamp on ferrite would be a current type 1:1 BALUN. I want to replace the flimsy longwire and the 'fence loop' looks promising. Could you (the group) comment on the use of this setup for LW, MW, and HF (each leg is about 85 feet long) with regard to the loops vertical polarization, and whether bending the loop at the right-angle would add or detract from its performance. While you're pondering, how about a vertical 'conical loop'? 85 foot a side would be a 340 foot loop with a 1 wavelength of 2.95 MHz. When the loop receives at 1 wavelength and more than one wavelength the receive pattern is in and out of the loop plane so a horizontal loop would look straight up. Most DX signals tend toward the horizon so this does not work as well. This type of antenna seems to work better during the dark hours for me and not as good during the daytime. Conical verticals also tend to look up. These are used in the HARP project to receive signals during tests. I don't know of anyone using this type for SW listening. It would be interesting to try it. -- Telamon Ventura, California |
Three Band : 49 & 31 & 22 Meter Bands Shortwave Listener (SWL) Tri-Band Dipole {Wire} Antenna On-the-Fence
On 19 Mar 2006 03:13:22 -0800, "RHF"
wrote: For One and All, Three Band : 49 & 31 & 22 Meter Bands Shortwave Listener (SWL) Tri-Band Dipole {Wire} Antenna On-the-Fence Top Dipole Antenna for the 31 Meter Band - Height above ground On-the-Fence = 5-Feet - Two 24.5 Feet long Single Wire Arms = 1/4 WL - Tip-to-Tip Length of 49.0 Feet = 1/2 WL - First 34 Inches for the Wire Antenna Elements (Dipole Arms) Sloping Up at 45 Degrees from the Matching Transformer (Balun) and then Flat. Center {Middle} Dipole Antenna for the 49 Meter Band - Height above ground On-the-Fence = 3-Feet - Two 38.5 Feet long Single Wire Arms = 1/4 WL - Tip-to-Tip Length of 77.0 Feet = 1/2 WL - Mounting-Point for the Matching Transformer (Balun). - Wire Antenna Elements (Dipole Arms) are Rigged Flat. Bottom Dipole Antenna for the 22 Meter Band - Height above ground On-the-Fence = 1-Feet - Two 17.1 Feet long Single Wire Arms = 1/4 WL - Tip-to-Tip Length of 34.20 Feet = 1/2 WL - First 34 Inches for the Wire Antenna Elements (Dipole Arms) Sloping Down at 45 Degrees from the Matching Transformer (Balun) and then Flat. * Requires a 4:1 Matching Transformer {Balun} * Ground Rod located in the ground at the Center-Point of the Dipole * 25-75 Foot of Coax Cable Feed-in-Line * Mount on a Fence that is at least 10 Feet away from the House / Radio Shack. * Use # 14 AWG Insulated Stranded Copper Wire for the Wire Antenna Elements of all three Dipole Antennas. TIP - For a "Receive Only" Shortwave Listener (SWL) Antenna - Simply Staple the Wire in-place On-the-Fence. -Or- Use Screw-In TV type Stand-Offs. Remember with All Wire Antennas : More Wire 'is' More Wire and nothing else is assured. . All are WELCOME and "Invited to Join" the Shortwave Listener (SWL) Antenna eGroup on YAHOO ! http://groups.yahoo.com/group/Shortwave-SWL-Antenna/ SWL ANTENNAS GROUP = http://tinyurl.com/an6tw . Some Say: On A Clear Day You Can See Forever. I Believe : On A Clear Night You Can Hear Forever . . . and Beyond , , , The BEYOND ! ! ! With a Shortwave Listening Antenna of your own making. "If You Build It {SWL Antenna} You Will Hear Them !" http://groups.yahoo.com/group/Shortwave-SWL-Antenna/ SHORTWAVE ANTENNA FORUM = http://tinyurl.com/an6tw . . . . . For a dipole skip the 4:1 balun - go straight to the coax or use a 1:1 unun. If you were building a folded dipole the 4:1 balun would be more appropriate. You can ground or not ground the dipole; it is a balanced antenna so grounding is a matter of lightning protection & providing a path for the static electricity to drain - a better path than draining to the radio. I guess the dipole that's 1 foot above the ground is for 'ground wave' reception 8-} |
Three Band : 49 & 31 & 22 Meter Bands Shortwave Listener (SWL) Tri-Band Dipole {Wire} Antenna On-the-Fence
How...,
1. For a dipole skip the 4:1 balun - go straight to the coax -R- Good advise for a Ham using the Dipole for a Specific Amateur Radio Meter Band - But for a Shortwave Listener (SWL) who is trying to use the Dipole as a general Antenna for All-SWL-Band reception the 4:1 Balun gives them more Listening-ability-across-the-Bands. REMEMBER - This is a Three Band : 49 & 31 & 22 Meter Bands Shortwave Listener (SWL) "Receive Only" Tri-Band Dipole {Wire} Antenna built on a On-the-Fence 2. or use a 1:1 unun. -R- An UnUn with a Dipole ? - - - Dipole to Twin Lead / Ladder Line = BalBal - - - Dipole to Coax Cable = BalUn 3. If you were building a folded dipole the 4:1 balun would be more appropriate. -R- Again this is a Three Band : 49 & 31 & 22 Meter Bands Shortwave Listener (SWL) "Receive Only" Tri-Band Dipole {Wire} Antenna built on a On-the-Fence The object of the 4:1 Balun is to intergrate the Signals developed by the Three Dipole Antenna Elements into the Single Coax Cable Feed-in-Line and provide better Across-the-Shortwave-Bands frequency coverage. 4. You can ground or not ground the dipole; it is a balanced antenna so grounding is a matter of lightning protection & providing a path for the static electricity to drain - a better path than draining to the radio. -R- Lightning Protection and a Static Electricity 'drain' Path are always two good things to achieve with any Shortwave Listener's (SWL) Antenna. 5. I guess the dipole that's 1 foot above the ground is for 'ground wave' reception 8-} -R- Wave Goodbye "How..." FWIW - A Dipole On-the-Fence would not be my first choice as a Shortwave Listener's (SWL) Antenna. But what can you do - If the ONLY place that you can build an Antenna is On-the-Fence ? ? ? and you don't have the Money for a Wellbrook Loop Antenna ? ? ? Plus someone has convinced you that the ONLY Antenna that is worth having is a Dipole - because it is a complete Antenna that does not require a ground to work. - - - So now all you know is that you have to build a Dipole Antenna and it's got to fit On-the-Fence [.] right now i am beginning to feel a little di-pole-er - iane ~ RHF |
Three Band : 49 & 31 & 22 Meter Bands Shortwave Listener (SWL) Tri-Band Dipole {Wire} Antenna On-the-Fence
On 19 Mar 2006 19:01:25 -0800, "RHF"
wrote: How..., 1. For a dipole skip the 4:1 balun - go straight to the coax -R- Good advise for a Ham using the Dipole for a Specific Amateur Radio Meter Band - But for a Shortwave Listener (SWL) who is trying to use the Dipole as a general Antenna for All-SWL-Band reception the 4:1 Balun gives them more Listening-ability-across-the-Bands. REMEMBER - This is a Three Band : 49 & 31 & 22 Meter Bands Shortwave Listener (SWL) "Receive Only" Tri-Band Dipole {Wire} Antenna built on a On-the-Fence I believe you are mis-applying the balun. A dipole has an inherent impedance of around 70 ohms - if using 50 ohm coax you could use a 1.5:1 or call it close enough and use a 1:1 balun (which I previously mis-stated as an unun) - or just go direct to the coax. As to giving 'more listenability' on other bands, well that's probably about as debated as the 9:1 balun with end-fed wires & inverted L antennas. One thing the balun does do is provide isolation between the antenna and feedline and this 'decoupling' can make for a quiter antenna system. 2. or use a 1:1 unun. -R- An UnUn with a Dipole ? - - - Dipole to Twin Lead / Ladder Line = BalBal - - - Dipole to Coax Cable = BalUn OOPS! My faux pas, should read 1:1 balun for Dipole to 75 ohm coax cable, 1.5:1 balun for Dipole to 50 ohm coax cable. Dipole to twinlead could be direct or use a 1:1 isolation transformer. 3. If you were building a folded dipole the 4:1 balun would be more appropriate. -R- Again this is a Three Band : 49 & 31 & 22 Meter Bands Shortwave Listener (SWL) "Receive Only" Tri-Band Dipole {Wire} Antenna built on a On-the-Fence The object of the 4:1 Balun is to intergrate the Signals developed by the Three Dipole Antenna Elements into the Single Coax Cable Feed-in-Line and provide better Across-the-Shortwave-Bands frequency coverage. The balun will not necessarily 'integrate the signals', in other than a 1:1 configuration it transforms impedance and allows you to go from balanced to unbalanced line. At some frequencies it may 'smooth out' the impedance mismatch, however if you want to combine the signals a triplexer would do the trick. 4. You can ground or not ground the dipole; it is a balanced antenna so grounding is a matter of lightning protection & providing a path for the static electricity to drain - a better path than draining to the radio. -R- Lightning Protection and a Static Electricity 'drain' Path are always two good things to achieve with any Shortwave Listener's (SWL) Antenna. Agreed. 5. I guess the dipole that's 1 foot above the ground is for 'ground wave' reception 8-} -R- Wave Goodbye "How..." Nope, not goodbye yet.......I'd like to rebut your rebuttal....... FWIW - A Dipole On-the-Fence would not be my first choice as a Shortwave Listener's (SWL) Antenna. But what can you do - If the ONLY place that you can build an Antenna is On-the-Fence ? ? ? and you don't have the Money for a Wellbrook Loop Antenna ? ? ? Plus someone has convinced you that the ONLY Antenna that is worth having is a Dipole - because it is a complete Antenna that does not require a ground to work. - - - So now all you know is that you have to build a Dipole Antenna and it's got to fit On-the-Fence [.] right now i am beginning to feel a little di-pole-er - iane ~ RHF . RHF - Granted, a fence mounted antenna is the best some folks can do; there are other options to the dipole such as an end-fed or a fence-loop; the former requiring a ground the latter not. Might I suggest to you the ARRL Antenna Book (not the end-all to antenna knowledge but a good start; it has a section on coupling the antenna to the feedline. They explain what I was trying to say in my original response to you in a better fashion than I can. They even describe a 1:1 balun which is what I mis-stated as an unun. Though you (and many participants here) are mainly interested in receive-only antennas; the principles apply equally to antennas used for transmit and receive. If you don't have a current copy of this ARRL publication see if you can get your hands on a used one - the physics haven't changed from year to year. What you have described will work, no doubt about it - but wouldn't you like to explore ways to make things work better? Howard |
Three Band : 49 & 31 & 22 Meter Bands Shortwave Listener (SWL) Tri-Band Dipole {Wire} Antenna On-the-Fence
On 19 Mar 2006 19:01:25 -0800, "RHF"
wrote: A 72-ohm fanned dipole connected to a single coax feed going to a 50-ohm input doesn't need a balun, especially a 4-1 jobbie. bob k5qwg How..., 1. For a dipole skip the 4:1 balun - go straight to the coax -R- Good advise for a Ham using the Dipole for a Specific Amateur Radio Meter Band - But for a Shortwave Listener (SWL) who is trying to use the Dipole as a general Antenna for All-SWL-Band reception the 4:1 Balun gives them more Listening-ability-across-the-Bands. REMEMBER - This is a Three Band : 49 & 31 & 22 Meter Bands Shortwave Listener (SWL) "Receive Only" Tri-Band Dipole {Wire} Antenna built on a On-the-Fence 2. or use a 1:1 unun. -R- An UnUn with a Dipole ? - - - Dipole to Twin Lead / Ladder Line = BalBal - - - Dipole to Coax Cable = BalUn 3. If you were building a folded dipole the 4:1 balun would be more appropriate. -R- Again this is a Three Band : 49 & 31 & 22 Meter Bands Shortwave Listener (SWL) "Receive Only" Tri-Band Dipole {Wire} Antenna built on a On-the-Fence The object of the 4:1 Balun is to intergrate the Signals developed by the Three Dipole Antenna Elements into the Single Coax Cable Feed-in-Line and provide better Across-the-Shortwave-Bands frequency coverage. 4. You can ground or not ground the dipole; it is a balanced antenna so grounding is a matter of lightning protection & providing a path for the static electricity to drain - a better path than draining to the radio. -R- Lightning Protection and a Static Electricity 'drain' Path are always two good things to achieve with any Shortwave Listener's (SWL) Antenna. 5. I guess the dipole that's 1 foot above the ground is for 'ground wave' reception 8-} -R- Wave Goodbye "How..." FWIW - A Dipole On-the-Fence would not be my first choice as a Shortwave Listener's (SWL) Antenna. But what can you do - If the ONLY place that you can build an Antenna is On-the-Fence ? ? ? and you don't have the Money for a Wellbrook Loop Antenna ? ? ? Plus someone has convinced you that the ONLY Antenna that is worth having is a Dipole - because it is a complete Antenna that does not require a ground to work. - - - So now all you know is that you have to build a Dipole Antenna and it's got to fit On-the-Fence [.] right now i am beginning to feel a little di-pole-er - iane ~ RHF . . . . . |
Three Band : 49 & 31 & 22 Meter Bands Shortwave Listener (SWL) Tri-Band Dipole {Wire} Antenna On-the-Fence
Howard,
1. One thing the balun does do is provide isolation between the antenna and feedline and this 'decoupling' can make for a quiter antenna system. -R- On this we can agree. 2. The balun will not necessarily 'integrate the signals', in other than a 1:1 configuration it transforms impedance and allows you to go from balanced to unbalanced line. At some frequencies it may 'smooth out' the impedance mismatch, however if you want to combine the signals a triplexer would do the trick. -R- Yes - The Balun would simply 'smooth out' the impedance mismatch between the combined Dipole Antenna Elements and the Coax Cable Feed-in-Line. - - - I have often though that a Bal(3)Un(1) for these types of Multi-Band (Multi-Element) type of 'combined' Antennas would be a better Matching Device. ? WHAT ? For the Three Dipole Antenna with One Coax Cable Feed-in-Line : * Three separate Primary Windings of 30 Turns # 1 - One for the 49m Dipole Wire Antenna Element # 2 - One for the 31m Dipole Wire Antenna Element # 3 - One for the 22m Dipole Wire Antenna Element * One Secondary Winding of 10 Turns for the Coax Cable Feed-in-Line. With All Four (4) Windings on a Single Ferrite Core. 3. ARRL Antenna Book -R- Books are wonderful and I do own a few books. But in the media of the NewsGroups (RRS) a WebPage (Link) that provides some information and Insight and is more directly accessable by most readers here. Plus my personal 'theme' here is to Keep It Simple And Practical (KISAP) with some basic "How To" Details (Description). that's where i am coming from - iane ~ RHF |
Three Band : 49 & 31 & 22 Meter Bands Shortwave Listener (SWL) Tri-Band Dipole {Wire} Antenna On-the-Fence
BM [K5QWG],
What you say is correct if the Fan Dipole is being used properly as a Single Band Amateur Antenna. How Ever ! ! ! :o) Take the same Antenna and . . . [ Remember we have an Antenna built On-the-Fence and for what ever reason {or lack of understanding} the Shortwave Listener (SWL) has decided the a Dipole is the only thing {Antenna} that they want. Plus the want a Mutli-Band Antenna to cover a few of the Shortwave Bands for Broad-Cast Program Listening (BCL) ] SO HERE WE GO AGAIN - - - - - - - - - - - - - - This is a Three Band : 49 & 31 & 22 Meter Bands Shortwave Listener (SWL) "Receive Only" Tri-Band Dipole {Wire} Antenna built on a On-the-Fence Question What Do We Do To Make It 'perfrom' ? ? ? ? To Perform - Or Not To Perform - - - Is That a Question ? A little better across the Shortwave Bands so we can "HEAR" a little of everything from 1.8 MHz to 30 MHz. Not a good answer but never the less a fair answer is the 4:1 Balun to 'smooth-out' the impedance mismatches from the Three (3) Dipole Antenna Elements and provide a fair 'match' from the three of them across the Shortwave Bands; know that they are One-Foot, Three-Feet and Five-Feet above the ground when Idealy they would be : 49m = 38.5 Feet above AGL 31m = 24.5 Feet above AGL 22m = 17.1 Feet above AGL alas - it is an imperfect world - iane ~ RHF |
Three Band : 49 & 31 & 22 Meter Bands Shortwave Listener (SWL) Tri-Band Dipole {Wire} Antenna On-the-Fence
On 21 Mar 2006 19:41:42 -0800, "RHF"
wrote: SO HERE WE GO AGAIN - - - - - - - - - - - - - - This is a Three Band : 49 & 31 & 22 Meter Bands Shortwave Listener (SWL) "Receive Only" Tri-Band Dipole {Wire} Antenna built on a On-the-Fence Question What Do We Do To Make It 'perfrom' ? ? ? ? To Perform - Or Not To Perform - - - Is That a Question ? A little better across the Shortwave Bands so we can "HEAR" a little of everything from 1.8 MHz to 30 MHz. Not a good answer but never the less a fair answer is the 4:1 Balun to 'smooth-out' the impedance mismatches from the Three (3) Dipole Antenna Elements and provide a fair 'match' from the three of them across the Shortwave Bands; know that they are One-Foot, Three-Feet and Five-Feet above the ground when Idealy they would be : 49m = 38.5 Feet above AGL 31m = 24.5 Feet above AGL 22m = 17.1 Feet above AGL alas - it is an imperfect world - iane ~ RHF . . . . I took into consideraton that there are three dipoles here, connected to a single transmission line -- so hopefully each will be within yelling distance, impedance wise, of 75 ohms, so there's no need for a 4-1 balun to a 50 ohm input. Unless you want to transpose 75 ohms to about 20 ohms? And if the antenna is less than a half-wavelength high at frequency, on a fence so to speak, the impedance could be anywhere between 40 and 90 ohms, according to chap. 20 of the ARRL handbook. Still no need for a 4-1 balun. Maybe a 1 to 1 choke balun, to sop up noise, but a 4-1? What is it, this high religious SW fever for baluns in this group :-) bob k5qwg |
Three Band : 49 & 31 & 22 Meter Bands Shortwave Listener (SWL) Tri-Band Dipole {Wire} Antenna On-the-Fence
In article ,
Bob Miller wrote: On 21 Mar 2006 19:41:42 -0800, "RHF" wrote: SO HERE WE GO AGAIN - - - - - - - - - - - - - - This is a Three Band : 49 & 31 & 22 Meter Bands Shortwave Listener (SWL) "Receive Only" Tri-Band Dipole {Wire} Antenna built on a On-the-Fence Question What Do We Do To Make It 'perfrom' ? ? ? ? To Perform - Or Not To Perform - - - Is That a Question ? A little better across the Shortwave Bands so we can "HEAR" a little of everything from 1.8 MHz to 30 MHz. Not a good answer but never the less a fair answer is the 4:1 Balun to 'smooth-out' the impedance mismatches from the Three (3) Dipole Antenna Elements and provide a fair 'match' from the three of them across the Shortwave Bands; know that they are One-Foot, Three-Feet and Five-Feet above the ground when Idealy they would be : 49m = 38.5 Feet above AGL 31m = 24.5 Feet above AGL 22m = 17.1 Feet above AGL I took into consideraton that there are three dipoles here, connected to a single transmission line -- so hopefully each will be within yelling distance, impedance wise, of 75 ohms, so there's no need for a 4-1 balun to a 50 ohm input. Unless you want to transpose 75 ohms to about 20 ohms? And if the antenna is less than a half-wavelength high at frequency, on a fence so to speak, the impedance could be anywhere between 40 and 90 ohms, according to chap. 20 of the ARRL handbook. Still no need for a 4-1 balun. Maybe a 1 to 1 choke balun, to sop up noise, but a 4-1? What is it, this high religious SW fever for baluns in this group :-) It's a way to current terminate a coax so it is not completely (100%) dependent on the the antenna impedance for the source termination. You want to have lengths of the dipoles to be high impedance respective to each other so the characteristic impedance of the sum says around the 72 to 50 ohm range. You would then want to then use a 1:1 BALUN. -- Telamon Ventura, California |
Three Band : 49 & 31 & 22 Meter Bands Shortwave Listener (SWL) Tri-Band Dipole {Wire} Antenna On-the-Fence
On Wed, 22 Mar 2006 21:01:37 GMT, Telamon
wrote: In article , Bob Miller wrote: On 21 Mar 2006 19:41:42 -0800, "RHF" wrote: SO HERE WE GO AGAIN - - - - - - - - - - - - - - This is a Three Band : 49 & 31 & 22 Meter Bands Shortwave Listener (SWL) "Receive Only" Tri-Band Dipole {Wire} Antenna built on a On-the-Fence Question What Do We Do To Make It 'perfrom' ? ? ? ? To Perform - Or Not To Perform - - - Is That a Question ? A little better across the Shortwave Bands so we can "HEAR" a little of everything from 1.8 MHz to 30 MHz. Not a good answer but never the less a fair answer is the 4:1 Balun to 'smooth-out' the impedance mismatches from the Three (3) Dipole Antenna Elements and provide a fair 'match' from the three of them across the Shortwave Bands; know that they are One-Foot, Three-Feet and Five-Feet above the ground when Idealy they would be : 49m = 38.5 Feet above AGL 31m = 24.5 Feet above AGL 22m = 17.1 Feet above AGL I took into consideraton that there are three dipoles here, connected to a single transmission line -- so hopefully each will be within yelling distance, impedance wise, of 75 ohms, so there's no need for a 4-1 balun to a 50 ohm input. Unless you want to transpose 75 ohms to about 20 ohms? And if the antenna is less than a half-wavelength high at frequency, on a fence so to speak, the impedance could be anywhere between 40 and 90 ohms, according to chap. 20 of the ARRL handbook. Still no need for a 4-1 balun. Maybe a 1 to 1 choke balun, to sop up noise, but a 4-1? What is it, this high religious SW fever for baluns in this group :-) It's a way to current terminate a coax so it is not completely (100%) dependent on the the antenna impedance for the source termination. You want to have lengths of the dipoles to be high impedance respective to each other so the characteristic impedance of the sum says around the 72 to 50 ohm range. You would then want to then use a 1:1 BALUN. H-Y-P-O-C-R-I-T-E ALERT!! |
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