[TowerTalk] High power 2:1 transformer was Re: 16om vertical and the number of radials

[Gary K9GS]

Let er rip Chuck. Post pictures.73,Gary K9GS
-------- Original message --------From: Chuck Dietz <w5prchuck at gmail.com> Date: 12/3/22  12:21 PM  (GMT-06:00) To: Grant Saviers <grants2 at pacbell.net> Cc: towertalk at contesting.com Subject: Re: [TowerTalk] High power 2:1 transformer was Re: 16om vertical
  and the number of radials Thanks for the info. I think I am going with 60 radials on the ground. Iwant to use the 160 vertical tower to support an 80 meter array around it.Elevated radials might make adjustments way more complicated. I have atractor and a good welder guy to weld a bracket and tube to a single plowshear to make a radial plow.Chuck W5PROn Sat, Dec 3, 2022 at 11:59 AM Grant Saviers <grants2 at pacbell.net> wrote:> The capacitors are on the 25 ohm side so the transmission line> transformer sees a low swr.  Hence, the caps need to handle 2x the> current.  The details are in my QEX article "Broad-banding a 160m> Vertical Antenna"  QEX May/June 2019.  (errata - pin #'s on the> connecting cable are incorrect).>> No problems with the match since putting it up, now at 101 confirmed on> 160m :) all on this antenna.>> The 8 elevated aluminum electric fence wire radials are all still> original. The top support (center of the T) was broken off by a falling> branch which was replace 10/2022.  However, I'm sure there is a lot of> loss (4+ db?) from being in a forest.  That's the price of free antenna> supports (110ft fir/cedar trees).>> I currently have 10-12" of snow (YUK a record) on the ground and heavy> snow on the radials (and droop).  That has changed the resonance up> about 50KHz.  So another nice capability of the tuner.>> Grant KZ1W>> On 12/3/2022 06:57, Chuck Dietz wrote:> > Grant, where is the series capacitor, before the un-un or between it and> > the antenna?> >> > Chuck W5PR> >> > On Fri, Dec 2, 2022 at 7:53 PM Grant Saviers <grants2 at pacbell.net> > <mailto:grants2 at pacbell.net>> wrote:> >> >     I've been using the 2:1 one for 7 years at QRO for a good match at> the> >     antenna as I don't have a tuner at the amp.  I can match < 1.4:1 the> >     entire band by switching in series capacitance in 50KHz steps to the> >     1.83 resonance.> >> >     Grant KZ1W> >> >     On 12/2/2022 13:05, marsh at ka5m.net <mailto:marsh at ka5m.net> wrote:> >      > Yes, match at the feedpoint.> >      >> >      > You might check out Balun Designs:> >      > https://www.balundesigns.com/1-2-balun-25-to-50-ohms-3kw-1213/> >     <https://www.balundesigns.com/1-2-balun-25-to-50-ohms-3kw-1213/>> >      >> >      > Marsh, KA5M> >      >> >      >> >      > -----Original Message-----> >      > From: TowerTalk <towertalk-bounces at contesting.com> >     <mailto:towertalk-bounces at contesting.com>> On Behalf Of Pete Smith> N4ZR> >      > Sent: Friday, December 02, 2022 2:39 PM> >      > To: towertalk at contesting.com <mailto:towertalk at contesting.com>> >      > Subject: [TowerTalk] High power 2:1 transformer was Re: 16om> >     vertical and the number of radials> >      >> >      > A somewhat related question - as the R component at the feedpoint> >     of my inverted L goes down toward 25 ohms, I've begun wondering if I> >     should do some matching at the feedpoint, rather than using my tuner> >     in the shack, even though feedline losses at 160 are relatively> >     low.  Can someone point me toward a good way to do a 2:1 downward> >     transformation?  I already have a common mode choke at the feedpoint.> >      >> >      > 73, Pete N4ZR> >      > Check out the new Reverse Beacon Network web server> >     at<https://reversebeacon.net <https://reversebeacon.net>>.> >      > For spots, please use your favorite> >      > "retail" DX cluster.> >      >> >      >> >      > _______________________________________________> >      >> >      >> >      >> >      > _______________________________________________> >      > TowerTalk mailing list> >      > TowerTalk at contesting.com <mailto:TowerTalk at contesting.com>> >      > http://lists.contesting.com/mailman/listinfo/towertalk> >     <http://lists.contesting.com/mailman/listinfo/towertalk>> >     _______________________________________________> >> >> >> >     _______________________________________________> >     TowerTalk mailing list> >     TowerTalk at contesting.com <mailto:TowerTalk at contesting.com>> >     http://lists.contesting.com/mailman/listinfo/towertalk> >     <http://lists.contesting.com/mailman/listinfo/towertalk>> >>______________________________________________________________________________________________TowerTalk mailing listTowerTalk at contesting.comhttp://lists.contesting.com/mailman/listinfo/towertalk