Topband: 1:2 UNUN
Date: Mon, 17 Jan 2022 20:18:52 + (UTC) From: Mike Furrey To: 'Kenny Silverman' , 'TopBand List' Subject: Re: Topband: 1:2 UNUN < Perhaps a "hair pin" match? I used a hair pin coil at the base of a vertical that was 35 ohms. <73, Mike WA5POK ## a simple helical hairpin is the real answer. Just compress / expand the coil for 1:1 swr. The coil will also DC ground the vertical. Dead simple. ## Tim's L network will also work, but the series L, and shunt C won't provide for DC grounding the vertical. Jim VE7RF _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
Re: Topband: 1:2 UNUN
Thanks for all the replies on and off the reflector. My antenna, now a 90' top loaded vertical with 60 x 100' radials, was not transmitting well. While trying to fix it, I changed from an inverted L to the top loaded configuration, and I stripped off the hairpin coil (1/4" copper tubing) and the choke. The antenna is working better, but it's likely due to the new top loaded configuration rather than the hairpin/choke. With the antenna tuned without the hairpin, I thought it would be easier to put on an UNUN rather than retuning the antenna and putting the hairpin back on, which will lower the frequency. 73, and I hope to CU in the 160 CW contest in 2 weeks. Kenny K2KW On Mon, Jan 17, 2022 at 3:18 PM Mike Furrey wrote: > Perhaps a "hair pin" match? I used a hair pin coil at the base of a > vertical that was 35 ohms. > > 73, Mike WA5POK > > > On Monday, January 17, 2022, 01:36:12 PM EST, Tim Duffy > wrote: > > > I match my 26 ohm feed point with a simple L network. One series coil then > a > shunt capacitor. Steps up to 50 ohms perfectly. > > 73 > Tim K3LR > > -Original Message- > From: Topband [mailto:topband-bounces+k3lr=k3lr@contesting.com] On > Behalf Of Richard (Rick) Karlquist > Sent: Monday, January 17, 2022 1:10 PM > To: Kenny Silverman; TopBand List > Subject: Re: Topband: 1:2 UNUN > > Maybe this will help: > > I use a 1:2.25 Unun (3 to 2 turns ratio). It will match 22.2 ohms > to 50 ohms. It is wound on a single 2.4 inch diameter core of 77 > material. A pair of RG-58 coax cables are wound around it in > tandem. I put on as many turns as would fit ... about 10 turns. > The shields of the two coax cables are wired in parallel. > > This results in essentially a trifilar winding (1. The shields; > 2. One of the center conductors 3. The other center conductor) > This trifilar winding can then be connected in the usual way to > get a 3 to 2 turns ratio autotransformer). The order of the > connections is: center conductor #1, then the shields, then > the #2 center conductor, in series. The radio drives > the 3 windings in series, and the antenna is tapped down to > utilize only 2 of them. I run this at 1,500 watts in > contests with no problems at all. > > The concept is extensible to a quadfilar winding constructed > from 3 coax cables in tandem (shields in parallel). This can > be wired with a 4 to 3 turns ratio resulting in a 1:1.77 UNUN. > This matches 28.125 ohms to 50 ohms. An alternate modality > I have used is to use two coax cables as in the 1:2.25 UNUN, > but make one of the coax cables from tri-ax. > > I can highly recommend UNUN's for the convenience factor if > your drive impedance is compatible with the available ratios. > They are broadband, no tuning. > > 73 > Rick N6RK > > On 1/17/2022 6:18 AM, Kenny Silverman wrote: > > Does anyone have a drawing on how to wind a 1500w 1:2 UNUN? And what > type > of core is needed? > > > > This is for my 160m vertical which is about 28 ohms. > > > > Regards , Kenny K2KW > > _ > > Searchable Archives: http://www.contesting.com/_topband - Topband > Reflector > > > > _ > Searchable Archives: http://www.contesting.com/_topband - Topband > Reflector > > _ > Searchable Archives: http://www.contesting.com/_topband - Topband > Reflector > _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
Re: Topband: 1:2 UNUN
I'll second Rick's approach, although I've not incorporated it yet. I built a parallel wire transformer per Sevick Fig 6-11. It measures just fine. Until it's installed I'm using an inverted-L with a shortened top wire which makes the feed capacitive. A shunt inductor forms an L-network and is a built-in static bleed. Wes N7WS. On 1/17/2022 11:34 AM, Tim Duffy wrote: I match my 26 ohm feed point with a simple L network. One series coil then a shunt capacitor. Steps up to 50 ohms perfectly. 73 Tim K3LR -Original Message- From: Topband [mailto:topband-bounces+k3lr=k3lr@contesting.com] On Behalf Of Richard (Rick) Karlquist Sent: Monday, January 17, 2022 1:10 PM To: Kenny Silverman; TopBand List Subject: Re: Topband: 1:2 UNUN Maybe this will help: I use a 1:2.25 Unun (3 to 2 turns ratio). It will match 22.2 ohms to 50 ohms. It is wound on a single 2.4 inch diameter core of 77 material. A pair of RG-58 coax cables are wound around it in tandem. I put on as many turns as would fit ... about 10 turns. The shields of the two coax cables are wired in parallel. This results in essentially a trifilar winding (1. The shields; 2. One of the center conductors 3. The other center conductor) This trifilar winding can then be connected in the usual way to get a 3 to 2 turns ratio autotransformer). The order of the connections is: center conductor #1, then the shields, then the #2 center conductor, in series. The radio drives the 3 windings in series, and the antenna is tapped down to utilize only 2 of them. I run this at 1,500 watts in contests with no problems at all. The concept is extensible to a quadfilar winding constructed from 3 coax cables in tandem (shields in parallel). This can be wired with a 4 to 3 turns ratio resulting in a 1:1.77 UNUN. This matches 28.125 ohms to 50 ohms. An alternate modality I have used is to use two coax cables as in the 1:2.25 UNUN, but make one of the coax cables from tri-ax. I can highly recommend UNUN's for the convenience factor if your drive impedance is compatible with the available ratios. They are broadband, no tuning. 73 Rick N6RK _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
Re: Topband: 1:2 UNUN
Perhaps a "hair pin" match? I used a hair pin coil at the base of a vertical that was 35 ohms. 73, Mike WA5POK On Monday, January 17, 2022, 01:36:12 PM EST, Tim Duffy wrote: I match my 26 ohm feed point with a simple L network. One series coil then a shunt capacitor. Steps up to 50 ohms perfectly. 73 Tim K3LR -Original Message- From: Topband [mailto:topband-bounces+k3lr=k3lr@contesting.com] On Behalf Of Richard (Rick) Karlquist Sent: Monday, January 17, 2022 1:10 PM To: Kenny Silverman; TopBand List Subject: Re: Topband: 1:2 UNUN Maybe this will help: I use a 1:2.25 Unun (3 to 2 turns ratio). It will match 22.2 ohms to 50 ohms. It is wound on a single 2.4 inch diameter core of 77 material. A pair of RG-58 coax cables are wound around it in tandem. I put on as many turns as would fit ... about 10 turns. The shields of the two coax cables are wired in parallel. This results in essentially a trifilar winding (1. The shields; 2. One of the center conductors 3. The other center conductor) This trifilar winding can then be connected in the usual way to get a 3 to 2 turns ratio autotransformer). The order of the connections is: center conductor #1, then the shields, then the #2 center conductor, in series. The radio drives the 3 windings in series, and the antenna is tapped down to utilize only 2 of them. I run this at 1,500 watts in contests with no problems at all. The concept is extensible to a quadfilar winding constructed from 3 coax cables in tandem (shields in parallel). This can be wired with a 4 to 3 turns ratio resulting in a 1:1.77 UNUN. This matches 28.125 ohms to 50 ohms. An alternate modality I have used is to use two coax cables as in the 1:2.25 UNUN, but make one of the coax cables from tri-ax. I can highly recommend UNUN's for the convenience factor if your drive impedance is compatible with the available ratios. They are broadband, no tuning. 73 Rick N6RK On 1/17/2022 6:18 AM, Kenny Silverman wrote: > Does anyone have a drawing on how to wind a 1500w 1:2 UNUN? And what type of core is needed? > > This is for my 160m vertical which is about 28 ohms. > > Regards , Kenny K2KW > _ > Searchable Archives: http://www.contesting.com/_topband - Topband Reflector > _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
Re: Topband: 1:2 UNUN
I match my 26 ohm feed point with a simple L network. One series coil then a shunt capacitor. Steps up to 50 ohms perfectly. 73 Tim K3LR -Original Message- From: Topband [mailto:topband-bounces+k3lr=k3lr@contesting.com] On Behalf Of Richard (Rick) Karlquist Sent: Monday, January 17, 2022 1:10 PM To: Kenny Silverman; TopBand List Subject: Re: Topband: 1:2 UNUN Maybe this will help: I use a 1:2.25 Unun (3 to 2 turns ratio). It will match 22.2 ohms to 50 ohms. It is wound on a single 2.4 inch diameter core of 77 material. A pair of RG-58 coax cables are wound around it in tandem. I put on as many turns as would fit ... about 10 turns. The shields of the two coax cables are wired in parallel. This results in essentially a trifilar winding (1. The shields; 2. One of the center conductors 3. The other center conductor) This trifilar winding can then be connected in the usual way to get a 3 to 2 turns ratio autotransformer). The order of the connections is: center conductor #1, then the shields, then the #2 center conductor, in series. The radio drives the 3 windings in series, and the antenna is tapped down to utilize only 2 of them. I run this at 1,500 watts in contests with no problems at all. The concept is extensible to a quadfilar winding constructed from 3 coax cables in tandem (shields in parallel). This can be wired with a 4 to 3 turns ratio resulting in a 1:1.77 UNUN. This matches 28.125 ohms to 50 ohms. An alternate modality I have used is to use two coax cables as in the 1:2.25 UNUN, but make one of the coax cables from tri-ax. I can highly recommend UNUN's for the convenience factor if your drive impedance is compatible with the available ratios. They are broadband, no tuning. 73 Rick N6RK On 1/17/2022 6:18 AM, Kenny Silverman wrote: > Does anyone have a drawing on how to wind a 1500w 1:2 UNUN? And what type of core is needed? > > This is for my 160m vertical which is about 28 ohms. > > Regards , Kenny K2KW > _ > Searchable Archives: http://www.contesting.com/_topband - Topband Reflector > _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
Re: Topband: 1:2 UNUN
Maybe this will help: I use a 1:2.25 Unun (3 to 2 turns ratio). It will match 22.2 ohms to 50 ohms. It is wound on a single 2.4 inch diameter core of 77 material. A pair of RG-58 coax cables are wound around it in tandem. I put on as many turns as would fit ... about 10 turns. The shields of the two coax cables are wired in parallel. This results in essentially a trifilar winding (1. The shields; 2. One of the center conductors 3. The other center conductor) This trifilar winding can then be connected in the usual way to get a 3 to 2 turns ratio autotransformer). The order of the connections is: center conductor #1, then the shields, then the #2 center conductor, in series. The radio drives the 3 windings in series, and the antenna is tapped down to utilize only 2 of them. I run this at 1,500 watts in contests with no problems at all. The concept is extensible to a quadfilar winding constructed from 3 coax cables in tandem (shields in parallel). This can be wired with a 4 to 3 turns ratio resulting in a 1:1.77 UNUN. This matches 28.125 ohms to 50 ohms. An alternate modality I have used is to use two coax cables as in the 1:2.25 UNUN, but make one of the coax cables from tri-ax. I can highly recommend UNUN's for the convenience factor if your drive impedance is compatible with the available ratios. They are broadband, no tuning. 73 Rick N6RK On 1/17/2022 6:18 AM, Kenny Silverman wrote: Does anyone have a drawing on how to wind a 1500w 1:2 UNUN? And what type of core is needed? This is for my 160m vertical which is about 28 ohms. Regards , Kenny K2KW _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
Re: Topband: 1:2 UNUN
Hi Pete, 1/4 wave electrical length. 89 feet for two RG-11 solid dielectric coaxes in parallel. 73 Frank W3LPL From: "Pete N4ZR N4ZR" To: "donovanf" Sent: Monday, January 17, 2022 5:12:48 PM Subject: Re: Topband: 1:2 UNUN lengths? 1/4 wave? 73, Pete N4ZR Check out the new Reverse Beacon Network web server at [ http://beta.reversebeacon.net/ | <http://beta.reversebeacon.net> ] . For spots, please use your favorite "retail" DX cluster. On 1/17/2022 11:29 AM, Frank W3LPL wrote: Hi Kenny, A very workable alternative is to use two lengths of 75 ohm coax in parallel. RG-11 is the best choice, but two lengths of RG-6 will also work. No need to coil it up, simply use it as part of your transmission line from your antenna base to your station. 73 Frank W3LPL - Original Message - From: "Kenneth Silverman" [ mailto:kenny.k...@gmail.com | ] To: "topband" [ mailto:topband@contesting.com | ] Sent: Monday, January 17, 2022 2:18:30 PM Subject: Topband: 1:2 UNUN Does anyone have a drawing on how to wind a 1500w 1:2 UNUN? And what type of core is needed? This is for my 160m vertical which is about 28 ohms. Regards , Kenny K2KW _ Searchable Archives: [ http://www.contesting.com/_topband | http://www.contesting.com/_topband ] - Topband Reflector _ Searchable Archives: [ http://www.contesting.com/_topband | http://www.contesting.com/_topband ] - Topband Reflector _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
Re: Topband: 1:2 UNUN
1/4 wavelength of 75 / 2 = 37.5 Ohms Will take your 28 ohms very close to 50. On Mon, Jan 17, 2022 at 8:47 AM Kenny Silverman wrote: > Thanks Frank. Are these 1/4 wl lines? And are T-connectors OK? > > Regards , Kenny K2KW > > > On Jan 17, 2022, at 11:29 AM, Frank W3LPL > wrote: > > > > Hi Kenny, > > > > A very workable alternative is to use two lengths of 75 ohm coax > > in parallel. RG-11 is the best choice, but two lengths of RG-6 > > will also work. No need to coil it up, simply use it as part > > of your transmission line from your antenna base to your station. > > > > 73 > > Frank > > W3LPL > > > > - Original Message - > > From: "Kenneth Silverman" > > To: "topband" > > Sent: Monday, January 17, 2022 2:18:30 PM > > Subject: Topband: 1:2 UNUN > > > > Does anyone have a drawing on how to wind a 1500w 1:2 UNUN? And what > type of core is needed? > > > > This is for my 160m vertical which is about 28 ohms. > > > > Regards , Kenny K2KW > > _ > > Searchable Archives: http://www.contesting.com/_topband - Topband > Reflector > _ > Searchable Archives: http://www.contesting.com/_topband - Topband > Reflector > _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
Re: Topband: 1:2 UNUN
Kenny - Yes, 1/4 wavelength electrical length. 89 feet of RG-11 (not the foam dielectric version used for CATV) UHF T connectors are fine, if you need any I'll give them to you. 73 Frank W3LPL - Original Message - From: "Kenneth Silverman" To: "donovanf" Cc: "topband" Sent: Monday, January 17, 2022 4:47:37 PM Subject: Re: Topband: 1:2 UNUN Thanks Frank. Are these 1/4 wl lines? And are T-connectors OK? Regards , Kenny K2KW > On Jan 17, 2022, at 11:29 AM, Frank W3LPL wrote: > > Hi Kenny, > > A very workable alternative is to use two lengths of 75 ohm coax > in parallel. RG-11 is the best choice, but two lengths of RG-6 > will also work. No need to coil it up, simply use it as part > of your transmission line from your antenna base to your station. > > 73 > Frank > W3LPL > > - Original Message - > From: "Kenneth Silverman" > To: "topband" > Sent: Monday, January 17, 2022 2:18:30 PM > Subject: Topband: 1:2 UNUN > > Does anyone have a drawing on how to wind a 1500w 1:2 UNUN? And what type of > core is needed? > > This is for my 160m vertical which is about 28 ohms. > > Regards , Kenny K2KW > _ > Searchable Archives: http://www.contesting.com/_topband - Topband Reflector _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
Re: Topband: 1:2 UNUN
Hi Kenny, A very workable alternative is to use two lengths of 75 ohm coax in parallel. RG-11 is the best choice, but two lengths of RG-6 will also work. No need to coil it up, simply use it as part of your transmission line from your antenna base to your station. 73 Frank W3LPL - Original Message - From: "Kenneth Silverman" To: "topband" Sent: Monday, January 17, 2022 2:18:30 PM Subject: Topband: 1:2 UNUN Does anyone have a drawing on how to wind a 1500w 1:2 UNUN? And what type of core is needed? This is for my 160m vertical which is about 28 ohms. Regards , Kenny K2KW _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
Re: Topband: 1:2 UNUN
Thanks Frank. Are these 1/4 wl lines? And are T-connectors OK? Regards , Kenny K2KW > On Jan 17, 2022, at 11:29 AM, Frank W3LPL wrote: > > Hi Kenny, > > A very workable alternative is to use two lengths of 75 ohm coax > in parallel. RG-11 is the best choice, but two lengths of RG-6 > will also work. No need to coil it up, simply use it as part > of your transmission line from your antenna base to your station. > > 73 > Frank > W3LPL > > - Original Message - > From: "Kenneth Silverman" > To: "topband" > Sent: Monday, January 17, 2022 2:18:30 PM > Subject: Topband: 1:2 UNUN > > Does anyone have a drawing on how to wind a 1500w 1:2 UNUN? And what type of > core is needed? > > This is for my 160m vertical which is about 28 ohms. > > Regards , Kenny K2KW > _ > Searchable Archives: http://www.contesting.com/_topband - Topband Reflector _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
Re: Topband: 1:2 UNUN
Kenny, I used three large torroid cores, 12AWG silver/teflon wire, and 10 turns/14 turns to match 25 ohms to 50 ohms. There is a picture of the transformer in my Phasing Switch Box at: https://www.n6ws.com/projects/ To give you some perspective of size, it is in a 8" x 8" box. 73, Bill N6WS On 1/17/2022 6:18 AM, Kenny Silverman wrote: Does anyone have a drawing on how to wind a 1500w 1:2 UNUN? And what type of core is needed? This is for my 160m vertical which is about 28 ohms. Regards , Kenny K2KW _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
Topband: 1:2 UNUN
Does anyone have a drawing on how to wind a 1500w 1:2 UNUN? And what type of core is needed? This is for my 160m vertical which is about 28 ohms. Regards , Kenny K2KW _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
