Re: Topband: K2AV 160m Folded Counterpoise Antenna - New Details Posted
The FCP is a single band solution. You can use an existing antenna, instead of the "simple solution" tune and prune for resonance, but then you have to supply your own separate method of getting to resonance, be that coil or capacitor. And depending on how far afield you are from the "simple" solution, you may have to do some impedance step up or step down with a unun of some sort. You WILL need to switch out the FCP to the antenna on bands other than 160. This has been done successfully. W0UCE uses the same inverted L with FCP on 160, as for an 80m end-fed halfwave inverted L. He switches out the entire 160 FCP-isolation transformer setup to a link coupled tank circuit matcher for 80 CW. Uses a high voltage high current vacuum relay for the job. The thing you need to keep the same regardless is the dimensions and specifics of the FCP and the isolation transformer, when you are using the antenna on 160. By the way, cutting back to +/- 16 feet for an 80 meter FCP allows you to get rid of using radials on 80m. But you do have to switch the correct FCP in/out. Not the simple solution, but workable, and combos like this are in use. 73, Guy On Sat, Dec 10, 2011 at 5:04 AM, James Rodenkirch wrote: > > Wonder if that FCP would be mo betta for my 43' vertical with three 25' > top hat wires mounted in a NORD sort of configuration, angled down at about > 45 degrees. > > I have 40 counterpoises- 25 are elevated about 3 feet above ground and 15 > are lying on the ground - and the length varies from 15 to 75 feet (I use > the antenna for 160 by switching a loading coil; switch it out for the > other bands). > > Thoughts? 72, Jim Rodenkirch, K9JWV > ___ UR RST IS ... ... ..9 QSB QSB - hw? BK
Re: Topband: K2AV 160m Folded Counterpoise Antenna - New Details Posted
Wonder if that FCP would be mo betta for my 43' vertical with three 25' top hat wires mounted in a NORD sort of configuration, angled down at about 45 degrees. I have 40 counterpoises- 25 are elevated about 3 feet above ground and 15 are lying on the ground - and the length varies from 15 to 75 feet (I use the antenna for 160 by switching a loading coil; switch it out for the other bands). Thoughts? 72, Jim Rodenkirch, K9JWV > Date: Fri, 9 Dec 2011 19:24:43 -0500 > From: kazerin...@aol.com > To: topband@contesting.com > Subject: Topband: K2AV 160m Folded Counterpoise Antenna - New Details Posted > > > Hullo folks. FWIW. > > I mounted the FCP on my "inverted J" which is about 60 up, 40 over, and > another 40 to 50 over again. About 150 feet of wire on the radiator. > > The FCP and transformer box are mounted about 7 feet up. Sent photos to > W0UCE since I still have the step ladder conveniently located. > > With 880pf of capacitance in series it is resonant right about 1830. The > autotuner in my ft-920 can tune it easily down at 1800, and runs into > trouble at 1860 up. Have not yet given the K2 tuner a look at the load. > > Using the Elecraft K2 S-meter as a field strength meter, sense antenna a > dummy load on a 7 foot jumper, full attenuation/no preamp, the OLD > antenna set up registered S5 on the K2 with 100w going into the antenna > from the FT-920 at its 1:1 SWR point. [K2 in the shack about 75 feet > from base of antenna and old antenna radials described below] > > After removing the elevated radials(they were in the way) and installing > the FCP system, yesterday I found that: > > 20w into the antenna from FT-920 now registers S5 on K2 > 40w into the antenna from FT-920 now registers S5 plus one bar on K2 > 60w into the antenna from FT-920 now registers S5 plus two bars K2 > 100w into the antenna from FT-920 now registers S9 (S5 plus three bars) > > I'm pretty sure my K2's S-meter is not well calibrated so there is not a > real quantitative measure there. But the new antenna is a lot better > than the system it replaced. (Note: The K2 bar graph has three bars > between s5 and s9.>5||9) > > There are still improvements I can make. There is a large coax > choke/balun wound with rg-58 that I'll be replacing with a much shorter > rg-8 jumper. > > The original crummy antenna(before FCP installed): > The old radials consisted of 8 radials about 6 feet above ground, all of > 35+/- feet in length. There were an additional 20 radials of various > lengths from 16 to 30 feet long. All were tied together at the bottom > of a coil, and the feedline ground tapped the coil where it provided the > best match. The radiator was the same ~150 feet of wire with the same > 880pf of capacitance in series. (A mix of 150pf and 82pf panasonic 3kv > ceramics in parallel). The 82pf caps will be switched out to move the > match should the relays prove capable of the task. > > The old set up allowed me to run US stations during ARRL 160m in 2010, > but never worked much dx or west coast with 100w. > > I wanted to get it all installed before ARRL 160m this year, but that > didn't happen. But maybe my 100w will be less like QRP for Stew Perry. > > For my own part, the 30 elevated radials were a maintenance nightmare, > although they were producing better results than 8 uniform length > radials. But every falling tree limb snagged one of them. The FCP > lowers the odds of being hit by a factor of 15. That should cut down on > radial repairs. Cha-Ching :) > > Other random thoughts.. > My installation of the FCP would have been easy to tune by trial and > error. With the antenna long, a large value air variable could be used. > Tune it to the sweet spot, measure the value of the air variable, and > replace it with the fixed value. I expect my own spark gap to be between > the vertical and the capacitors. > > Thanks very much to K2AV for his help with the project. Test drive > for Stew Perry. > > 73 de w4kaz > > > > ___ > UR RST IS ... ... ..9 QSB QSB - hw? BK ___ UR RST IS ... ... ..9 QSB QSB - hw? BK
Topband: K2AV 160m Folded Counterpoise Antenna - New Details Posted
Hullo folks. FWIW. I mounted the FCP on my "inverted J" which is about 60 up, 40 over, and another 40 to 50 over again. About 150 feet of wire on the radiator. The FCP and transformer box are mounted about 7 feet up. Sent photos to W0UCE since I still have the step ladder conveniently located. With 880pf of capacitance in series it is resonant right about 1830. The autotuner in my ft-920 can tune it easily down at 1800, and runs into trouble at 1860 up. Have not yet given the K2 tuner a look at the load. Using the Elecraft K2 S-meter as a field strength meter, sense antenna a dummy load on a 7 foot jumper, full attenuation/no preamp, the OLD antenna set up registered S5 on the K2 with 100w going into the antenna from the FT-920 at its 1:1 SWR point. [K2 in the shack about 75 feet from base of antenna and old antenna radials described below] After removing the elevated radials(they were in the way) and installing the FCP system, yesterday I found that: 20w into the antenna from FT-920 now registers S5 on K2 40w into the antenna from FT-920 now registers S5 plus one bar on K2 60w into the antenna from FT-920 now registers S5 plus two bars K2 100w into the antenna from FT-920 now registers S9 (S5 plus three bars) I'm pretty sure my K2's S-meter is not well calibrated so there is not a real quantitative measure there. But the new antenna is a lot better than the system it replaced. (Note: The K2 bar graph has three bars between s5 and s9.>5||9) There are still improvements I can make. There is a large coax choke/balun wound with rg-58 that I'll be replacing with a much shorter rg-8 jumper. The original crummy antenna(before FCP installed): The old radials consisted of 8 radials about 6 feet above ground, all of 35+/- feet in length. There were an additional 20 radials of various lengths from 16 to 30 feet long. All were tied together at the bottom of a coil, and the feedline ground tapped the coil where it provided the best match. The radiator was the same ~150 feet of wire with the same 880pf of capacitance in series. (A mix of 150pf and 82pf panasonic 3kv ceramics in parallel). The 82pf caps will be switched out to move the match should the relays prove capable of the task. The old set up allowed me to run US stations during ARRL 160m in 2010, but never worked much dx or west coast with 100w. I wanted to get it all installed before ARRL 160m this year, but that didn't happen. But maybe my 100w will be less like QRP for Stew Perry. For my own part, the 30 elevated radials were a maintenance nightmare, although they were producing better results than 8 uniform length radials. But every falling tree limb snagged one of them. The FCP lowers the odds of being hit by a factor of 15. That should cut down on radial repairs. Cha-Ching :) Other random thoughts.. My installation of the FCP would have been easy to tune by trial and error. With the antenna long, a large value air variable could be used. Tune it to the sweet spot, measure the value of the air variable, and replace it with the fixed value. I expect my own spark gap to be between the vertical and the capacitors. Thanks very much to K2AV for his help with the project. Test drive for Stew Perry. 73 de w4kaz ___ UR RST IS ... ... ..9 QSB QSB - hw? BK
Re: Topband: K2AV 160m Folded Counterpoise Antenna - New Details Posted
very interesting, the FCP is a way to allow the real estate challenged (no place for a true ground radial system, or a long high vertical antenna) to get something that will do more than just warm worms i would think the FCP would help those who do not have the opportunity for a 3/8 or 1/2 wave inverted L or vertical to not burn up all the power in their back yard barbecue area. my 120 up 130 out has a very driving point high impedance, so the current going into the counter poise would be very small compared to what would go into it with a 1/4 wave radiating element mike w7dra Get Free Email with Video Mail & Video Chat! http://www.juno.com/freeemail?refcd=JUTAGOUT1FREM0210 ___ UR RST IS ... ... ..9 QSB QSB - hw? BK
Re: Topband: K2AV 160m Folded Counterpoise Antenna - New Details Posted
Hi Guy, Many Thanks for you info. I plan to build the transformer. I am wondering how you housed the unit?? Thanks in advance for your input... 73, Ted K2QMF On Thu, 8 Dec 2011 22:46:47 -0500 Guy Olinger K2AV writes: > Just a word on ferrite beads, and other kinds of baluns. Trust us, > if it > could be done wrong, we blew it, if it could burn, we burned it, if > it > could be cracked, we shattered it, if it couldn't stand up to 1.5 > kw, we > smoked it. We tried every possible short cut and cheep trick > imaginable. > Anything except winding a special transformer that we couldn't buy > ready-made off a shelf somewhere. We got where we got because > ultimately > only a rugged isolation transformer would get it done. > > We are NOT opposed to your verifying our experience in that regard, > by > starting with beads and working your way up. Get in a supply of > tranquilizers before you start. Only do one better than we did, > take > pictures/video of the carnage for the entertainment of the masses. > > The specific construction of the transformer stands up to > brick-on-key 1.5 > kw and runs cold. There is a reason for the low mu powdered iron > choice. > > 73, Guy. > > On Thu, Dec 8, 2011 at 10:27 PM, Mike Waters > wrote: > > > On Thu, Dec 8, 2011 at 7:21 PM, W0UCE wrote: > > > > > * The ONLY means of achieving the required degree of > Isolation is > > to > > > use the Isolation Transformer as specified by K2AV > > > > > > > I was thinking of sliding a whole bunch of ferrite beads over the > coax > > feedline right at the end. But I'll take your word for it. > > > > This is all very interesting. I'd sure like to try Guy's invention > myself. > > > > 73, Mike > > www.w0btu.com > > ___ > > UR RST IS ... ... ..9 QSB QSB - hw? BK > > > ___ > UR RST IS ... ... ..9 QSB QSB - hw? BK > 53 Year Old Mom Looks 33 The Stunning Results of Her Wrinkle Trick Has Botox Doctors Worried http://thirdpartyoffers.juno.com/TGL3141/4ee238eba66bf91831ast04vuc ___ UR RST IS ... ... ..9 QSB QSB - hw? BK
Re: Topband: K2AV 160m Folded Counterpoise Antenna - New Details Posted
- Original Message - From: "Rick Karlquist" To: "W0UCE" Cc: ; Sent: Thursday, December 08, 2011 9:41 PM Subject: Re: Topband: K2AV 160m Folded Counterpoise Antenna - New Details Posted > W0UCE wrote: > >> * The ONLY means of achieving the required degree of Isolation is to >> use the Isolation Transformer as specified by K2AV >> * Tests using 1:1 Baluns and Line Isolators have ALL FAILED - you >> waste RF Power, Time and Money unless the specified xfmr is installed >> * DO NOT attempt to use Insulated Window Line for the FCP - We already >> tried it and it does not work - too lossy >> * Use #12 Bare wire for the FCP elements - Moisture gathers on >> insulated wire and detunes the FCP > > I haven't built this system, but the suggestions above make sense. > I have been trying to encourage using transformers instead of baluns > on 160 meters for years, but it's a tough sell to overcome the balun > habit. The tendency for loss in the open wire line also makes > sense. It is well known that window line is lossy when wet. > What is new here is that the Q is so high that you can't even > use insulated wire for open wire line. It would be interesting > to see if teflon insulated wire worked OK. The electric field > is maximum right at the conductor surface, so the insulation has > a considerable effect on characteristic impedance, thus I could > imagine it would affect loss too. I am feeding my vertical > using 850 feet of open wire line with XHHW insulation (whatever > that is made out of). It would be interesting to measure the > loss on a rainy day and see how much it increased. It's only > a few tenths of a dB when dry (the wires are 4 AWG aluminum). > > Rick N6RK Using a 120VAC 60Hz source and a 10A load the loss in 850' of #4 copper is 5.1V or 4.2% With aluminum it is 7.3V and 6.1%. It only gets worse at RF and once you reach about 3dB loss the input VSWR flattens out until it appears to equal the line impedance. Ground losses in a vertical have the same effect. Adding a pad between the signal source and DUT in the lab is the standard procedure to eliminate a matching problem. Carl KM1H ___ UR RST IS ... ... ..9 QSB QSB - hw? BK
Re: Topband: K2AV 160m Folded Counterpoise Antenna - New Details Posted
An actual pic of this transformer would be worth a thousand words. The drawings are great but I'd love to see this thing wound and connected for real. I don't have any experience with such things so having a pic to show details of how it works when drawings meet reality is priceless. Thanks for all this, pretty interesting. On Thu, Dec 8, 2011 at 7:21 PM, W0UCE wrote: > New information, details and drawings for the K2AV 160m Folded Counterpoise > (FCP) System, Isolation Transformer and Installation Notes have been posted > on my website. > > > > http://www.w0uce.net/K2AVantennas.html > > > > If you are interested in building an FCP versus putting in a dense radial > field heed the following advise: > > * The ONLY means of achieving the required degree of Isolation is to > use the Isolation Transformer as specified by K2AV > * Tests using 1:1 Baluns and Line Isolators have ALL FAILED - you > waste RF Power, Time and Money unless the specified xfmr is installed > * DO NOT attempt to use Insulated Window Line for the FCP - We > already > tried it and it does not work - too lossy > * Use #12 Bare wire for the FCP elements - Moisture gathers on > insulated wire and detunes the FCP > * Use 4" spacing between FCP elements > * Small diameter PVC Pipe Spreaders work well - use caps on both ends > and put a small weep hole in the bottom cap > * It is best to install the FCP in a straight line the overall length > is 66' if bends are necessary make them near the ends of the elements > > > > 73, > > Jack W0UCE > > ___ > UR RST IS ... ... ..9 QSB QSB - hw? BK > ___ UR RST IS ... ... ..9 QSB QSB - hw? BK
Re: Topband: K2AV 160m Folded Counterpoise Antenna - New Details Posted
I dont know what kind of an isolatuion transformer you guys are using, i come from a vintage view point where no ferrite or coax is ever used except to go from the transmitter final coil to the antenna coil. coupling is just some #14 insulated wire around the whatever coil i am going from to a wiinding on whatever coil i am going to, loop coupling everywhere, even in my receiver designs for antenna tuning make the coil the length needed to get an swr =1.0x or so, no matter what size of variable cap you need to resonate mike w7dra On Thu, 8 Dec 2011 18:41:41 -0800 "Rick Karlquist" writes: > W0UCE wrote: > > > *The ONLY means of achieving the required degree of > Isolation is to > > use the Isolation Transformer as specified by K2AV > > *Tests using 1:1 Baluns and Line Isolators have ALL FAILED > - you > > waste RF Power, Time and Money unless the specified xfmr is > installed > > *DO NOT attempt to use Insulated Window Line for the FCP - > We already > > tried it and it does not work - too lossy > > *Use #12 Bare wire for the FCP elements - Moisture gathers > on > > insulated wire and detunes the FCP > > I haven't built this system, but the suggestions above make sense. > I have been trying to encourage using transformers instead of > baluns > on 160 meters for years, but it's a tough sell to overcome the > balun > habit. The tendency for loss in the open wire line also makes > sense. It is well known that window line is lossy when wet. > What is new here is that the Q is so high that you can't even > use insulated wire for open wire line. It would be interesting > to see if teflon insulated wire worked OK. The electric field > is maximum right at the conductor surface, so the insulation has > a considerable effect on characteristic impedance, thus I could > imagine it would affect loss too. I am feeding my vertical > using 850 feet of open wire line with XHHW insulation (whatever > that is made out of). It would be interesting to measure the > loss on a rainy day and see how much it increased. It's only > a few tenths of a dB when dry (the wires are 4 AWG aluminum). > > Rick N6RK > > ___ > UR RST IS ... ... ..9 QSB QSB - hw? BK > 2.6% Mortgage Refinance No Hidden Fees - 3.14% APR. Calculate New Payment. No SSN req http://thirdpartyoffers.juno.com/TGL3141/4ee18c26bacc18f4751st02vuc ___ UR RST IS ... ... ..9 QSB QSB - hw? BK
Re: Topband: K2AV 160m Folded Counterpoise Antenna - New Details Posted
Im currently one of those ' Limited Space 160 Ops' .. @ moment im using an 'Inv L' to use the term loosley. ( Diagram Attached ) I am really thinking about trying one of these FCP's.. altho it would take some considerable work removing whats already in place.. but no big deal. My question is this.. the actuall FCP Element(s) can they be aranged so that from the Feed Point they would look like an extreemley wide 'V' and not straight? ( Instead of 180 deg to one another .. say mabey 130 deg) Also.. would near buy house(s) hinder their tuning / Operation @ published lengths? If I was to install one here.. to keep my current feed point position where it is ( best for vertical rise in my case ) .. the Feed would be @ corner of house.. with 33' of the FCP in the back yard in the clear @ 8-10' up.. and the other 1/2 (33' ) of the FCP running alongside my house.. @ 8-10' up. -Steve Raas N2JDQ On Thu, Dec 8, 2011 at 10:46 PM, Guy Olinger K2AV wrote: > Just a word on ferrite beads, and other kinds of baluns. Trust us, if it > could be done wrong, we blew it, if it could burn, we burned it, if it > could be cracked, we shattered it, if it couldn't stand up to 1.5 kw, we > smoked it. We tried every possible short cut and cheep trick imaginable. > Anything except winding a special transformer that we couldn't buy > ready-made off a shelf somewhere. We got where we got because ultimately > only a rugged isolation transformer would get it done. > > We are NOT opposed to your verifying our experience in that regard, by > starting with beads and working your way up. Get in a supply of > tranquilizers before you start. Only do one better than we did, take > pictures/video of the carnage for the entertainment of the masses. > > The specific construction of the transformer stands up to brick-on-key 1.5 > kw and runs cold. There is a reason for the low mu powdered iron choice. > > 73, Guy. > > On Thu, Dec 8, 2011 at 10:27 PM, Mike Waters wrote: > > > On Thu, Dec 8, 2011 at 7:21 PM, W0UCE wrote: > > > > > * The ONLY means of achieving the required degree of Isolation is > > to > > > use the Isolation Transformer as specified by K2AV > > > > > > > I was thinking of sliding a whole bunch of ferrite beads over the coax > > feedline right at the end. But I'll take your word for it. > > > > This is all very interesting. I'd sure like to try Guy's invention > myself. > > > > 73, Mike > > www.w0btu.com > > ___ > > UR RST IS ... ... ..9 QSB QSB - hw? BK > > > ___ > UR RST IS ... ... ..9 QSB QSB - hw? BK > ___ UR RST IS ... ... ..9 QSB QSB - hw? BK
Re: Topband: K2AV 160m Folded Counterpoise Antenna - New Details Posted
We built and tested a window line FCP - when it was dry and wet... it was a dismal failure. Been there, done that and I have three lengths of window line cut and connected together in a 33, 66, 66 section globs in my storage shed. It is available immediately to the highest bidder, shipping and handling at buyer's expense... And... BTW: A loss calculator for wet or dry window line available at: http://vk1od.net/calc/tl/tlc.php >sense. It is well known that window line is >lossy when wet. I am curious if anyone has actually measured this over a range of frequencies. Afaik, the "it's lossy when wet" is based on a model that I've seen some say overstates the loss for a wet window line. > I am feeding my vertical >using 850 feet of open wire line with XHHW >insulation (whatever >that is made out of). XHHW uses cross-linked polyethylene insulation. It is very tough (it's used on triplex-type power lines), and I would expect it to have essentially the same electrical properties as "regular" polyethylene wire since it's very nearly the same chemical composition. > It would be interesting to measure the >loss on a rainy day and see how much it >increased. >Rick N6RK You could probably do a more controlled test just wetting the lines with a garden hose :-) -Bill [Sent using Blackberry Messaging] ___ UR RST IS ... ... ..9 QSB QSB - hw? BK
Re: Topband: K2AV 160m Folded Counterpoise Antenna - New Details Posted
Just a word on ferrite beads, and other kinds of baluns. Trust us, if it could be done wrong, we blew it, if it could burn, we burned it, if it could be cracked, we shattered it, if it couldn't stand up to 1.5 kw, we smoked it. We tried every possible short cut and cheep trick imaginable. Anything except winding a special transformer that we couldn't buy ready-made off a shelf somewhere. We got where we got because ultimately only a rugged isolation transformer would get it done. We are NOT opposed to your verifying our experience in that regard, by starting with beads and working your way up. Get in a supply of tranquilizers before you start. Only do one better than we did, take pictures/video of the carnage for the entertainment of the masses. The specific construction of the transformer stands up to brick-on-key 1.5 kw and runs cold. There is a reason for the low mu powdered iron choice. 73, Guy. On Thu, Dec 8, 2011 at 10:27 PM, Mike Waters wrote: > On Thu, Dec 8, 2011 at 7:21 PM, W0UCE wrote: > > > * The ONLY means of achieving the required degree of Isolation is > to > > use the Isolation Transformer as specified by K2AV > > > > I was thinking of sliding a whole bunch of ferrite beads over the coax > feedline right at the end. But I'll take your word for it. > > This is all very interesting. I'd sure like to try Guy's invention myself. > > 73, Mike > www.w0btu.com > ___ > UR RST IS ... ... ..9 QSB QSB - hw? BK > ___ UR RST IS ... ... ..9 QSB QSB - hw? BK
Re: Topband: K2AV 160m Folded Counterpoise Antenna - New Details Posted
>sense. It is well known that window line is >lossy when wet. I am curious if anyone has actually measured this over a range of frequencies. Afaik, the "it's lossy when wet" is based on a model that I've seen some say overstates the loss for a wet window line. > I am feeding my vertical >using 850 feet of open wire line with XHHW >insulation (whatever >that is made out of). XHHW uses cross-linked polyethylene insulation. It is very tough (it's used on triplex-type power lines), and I would expect it to have essentially the same electrical properties as "regular" polyethylene wire since it's very nearly the same chemical composition. > It would be interesting to measure the >loss on a rainy day and see how much it >increased. >Rick N6RK You could probably do a more controlled test just wetting the lines with a garden hose :-) -Bill [Sent using Blackberry Messaging] ___ UR RST IS ... ... ..9 QSB QSB - hw? BK
Re: Topband: K2AV 160m Folded Counterpoise Antenna - New Details Posted
On Thu, Dec 8, 2011 at 7:21 PM, W0UCE wrote: > * The ONLY means of achieving the required degree of Isolation is to > use the Isolation Transformer as specified by K2AV > I was thinking of sliding a whole bunch of ferrite beads over the coax feedline right at the end. But I'll take your word for it. This is all very interesting. I'd sure like to try Guy's invention myself. 73, Mike www.w0btu.com ___ UR RST IS ... ... ..9 QSB QSB - hw? BK
Re: Topband: K2AV 160m Folded Counterpoise Antenna - New Details Posted
We appreciate your comments regarding FCP construction Rick. We have Guy, K2AV to thank - he is the developer, designer, engineer and I am fortunate to be his Field Trial "Guinea Pig" -Original Message- From: Rick Karlquist [mailto:rich...@karlquist.com] Sent: Thursday, December 08, 2011 9:42 PM To: W0UCE Cc: topband@contesting.com; cw...@yahoogroups.com Subject: Re: Topband: K2AV 160m Folded Counterpoise Antenna - New Details Posted W0UCE wrote: > * The ONLY means of achieving the required degree of Isolation is to > use the Isolation Transformer as specified by K2AV > * Tests using 1:1 Baluns and Line Isolators have ALL FAILED - you > waste RF Power, Time and Money unless the specified xfmr is installed > * DO NOT attempt to use Insulated Window Line for the FCP - We already > tried it and it does not work - too lossy > * Use #12 Bare wire for the FCP elements - Moisture gathers on > insulated wire and detunes the FCP I haven't built this system, but the suggestions above make sense. I have been trying to encourage using transformers instead of baluns on 160 meters for years, but it's a tough sell to overcome the balun habit. The tendency for loss in the open wire line also makes sense. It is well known that window line is lossy when wet. What is new here is that the Q is so high that you can't even use insulated wire for open wire line. It would be interesting to see if teflon insulated wire worked OK. The electric field is maximum right at the conductor surface, so the insulation has a considerable effect on characteristic impedance, thus I could imagine it would affect loss too. I am feeding my vertical using 850 feet of open wire line with XHHW insulation (whatever that is made out of). It would be interesting to measure the loss on a rainy day and see how much it increased. It's only a few tenths of a dB when dry (the wires are 4 AWG aluminum). Rick N6RK ___ UR RST IS ... ... ..9 QSB QSB - hw? BK
Re: Topband: K2AV 160m Folded Counterpoise Antenna - New Details Posted
Full Legal Limit has been used on my and K2AV's Inverted L Antennas with FCP and Isolation Transformers as described without any problems. -Original Message- From: Charlie Young [mailto:weeks...@hotmail.com] Sent: Thursday, December 08, 2011 9:36 PM To: w0...@nc.rr.com; topband@contesting.com Subject: RE: Topband: K2AV 160m Folded Counterpoise Antenna - New Details Posted Thanks for posting the drawing. What is the projected power handling capability of the described feed transformer? 73 Charlie (Chas) N8RR > From: w0...@nc.rr.com > To: topband@contesting.com; cw...@yahoogroups.com > Date: Thu, 8 Dec 2011 20:21:04 -0500 > Subject: Topband: K2AV 160m Folded Counterpoise Antenna - New Details Posted > > New information, details and drawings for the K2AV 160m Folded Counterpoise > (FCP) System, Isolation Transformer and Installation Notes have been posted > on my website. > > > > http://www.w0uce.net/K2AVantennas.html > > > > If you are interested in building an FCP versus putting in a dense radial > field heed the following advise: > > * The ONLY means of achieving the required degree of Isolation is to > use the Isolation Transformer as specified by K2AV > * Tests using 1:1 Baluns and Line Isolators have ALL FAILED - you > waste RF Power, Time and Money unless the specified xfmr is installed > * DO NOT attempt to use Insulated Window Line for the FCP - We already > tried it and it does not work - too lossy > * Use #12 Bare wire for the FCP elements - Moisture gathers on > insulated wire and detunes the FCP > * Use 4" spacing between FCP elements > * Small diameter PVC Pipe Spreaders work well - use caps on both ends > and put a small weep hole in the bottom cap > * It is best to install the FCP in a straight line the overall length > is 66' if bends are necessary make them near the ends of the elements > > > > 73, > > Jack W0UCE > > ___ > UR RST IS ... ... ..9 QSB QSB - hw? BK ___ UR RST IS ... ... ..9 QSB QSB - hw? BK
Re: Topband: K2AV 160m Folded Counterpoise Antenna - New Details Posted
W0UCE wrote: > * The ONLY means of achieving the required degree of Isolation is to > use the Isolation Transformer as specified by K2AV > * Tests using 1:1 Baluns and Line Isolators have ALL FAILED - you > waste RF Power, Time and Money unless the specified xfmr is installed > * DO NOT attempt to use Insulated Window Line for the FCP - We already > tried it and it does not work - too lossy > * Use #12 Bare wire for the FCP elements - Moisture gathers on > insulated wire and detunes the FCP I haven't built this system, but the suggestions above make sense. I have been trying to encourage using transformers instead of baluns on 160 meters for years, but it's a tough sell to overcome the balun habit. The tendency for loss in the open wire line also makes sense. It is well known that window line is lossy when wet. What is new here is that the Q is so high that you can't even use insulated wire for open wire line. It would be interesting to see if teflon insulated wire worked OK. The electric field is maximum right at the conductor surface, so the insulation has a considerable effect on characteristic impedance, thus I could imagine it would affect loss too. I am feeding my vertical using 850 feet of open wire line with XHHW insulation (whatever that is made out of). It would be interesting to measure the loss on a rainy day and see how much it increased. It's only a few tenths of a dB when dry (the wires are 4 AWG aluminum). Rick N6RK ___ UR RST IS ... ... ..9 QSB QSB - hw? BK
Re: Topband: K2AV 160m Folded Counterpoise Antenna - New Details Posted
Thanks for posting the drawing. What is the projected power handling capability of the described feed transformer? 73 Charlie (Chas) N8RR > From: w0...@nc.rr.com > To: topband@contesting.com; cw...@yahoogroups.com > Date: Thu, 8 Dec 2011 20:21:04 -0500 > Subject: Topband: K2AV 160m Folded Counterpoise Antenna - New Details Posted > > New information, details and drawings for the K2AV 160m Folded Counterpoise > (FCP) System, Isolation Transformer and Installation Notes have been posted > on my website. > > > > http://www.w0uce.net/K2AVantennas.html > > > > If you are interested in building an FCP versus putting in a dense radial > field heed the following advise: > > * The ONLY means of achieving the required degree of Isolation is to > use the Isolation Transformer as specified by K2AV > * Tests using 1:1 Baluns and Line Isolators have ALL FAILED - you > waste RF Power, Time and Money unless the specified xfmr is installed > * DO NOT attempt to use Insulated Window Line for the FCP - We already > tried it and it does not work - too lossy > * Use #12 Bare wire for the FCP elements - Moisture gathers on > insulated wire and detunes the FCP > * Use 4" spacing between FCP elements > * Small diameter PVC Pipe Spreaders work well - use caps on both ends > and put a small weep hole in the bottom cap > * It is best to install the FCP in a straight line the overall length > is 66' if bends are necessary make them near the ends of the elements > > > > 73, > > Jack W0UCE > > ___ > UR RST IS ... ... ..9 QSB QSB - hw? BK ___ UR RST IS ... ... ..9 QSB QSB - hw? BK
Topband: K2AV 160m Folded Counterpoise Antenna - New Details Posted
New information, details and drawings for the K2AV 160m Folded Counterpoise (FCP) System, Isolation Transformer and Installation Notes have been posted on my website. http://www.w0uce.net/K2AVantennas.html If you are interested in building an FCP versus putting in a dense radial field heed the following advise: * The ONLY means of achieving the required degree of Isolation is to use the Isolation Transformer as specified by K2AV * Tests using 1:1 Baluns and Line Isolators have ALL FAILED - you waste RF Power, Time and Money unless the specified xfmr is installed * DO NOT attempt to use Insulated Window Line for the FCP - We already tried it and it does not work - too lossy * Use #12 Bare wire for the FCP elements - Moisture gathers on insulated wire and detunes the FCP * Use 4" spacing between FCP elements * Small diameter PVC Pipe Spreaders work well - use caps on both ends and put a small weep hole in the bottom cap * It is best to install the FCP in a straight line the overall length is 66' if bends are necessary make them near the ends of the elements 73, Jack W0UCE ___ UR RST IS ... ... ..9 QSB QSB - hw? BK
