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Re: [TowerTalk] question about a matching transformer

To: <towertalk@contesting.com>
Subject: Re: [TowerTalk] question about a matching transformer
From: "StellarCAT" <rxdesign@ssvecnet.com>
Date: Thu, 14 Jul 2016 07:08:02 -0400
List-post: <towertalk@contesting.com">mailto:towertalk@contesting.com>
it is 2X monos and I want to be able to select all combo's including out of phase... besides - it SHOULD work! It too is dead simple - supposedly.

thanks though.

g.



-----Original Message----- From: Jim Thomson
Sent: Wednesday, July 13, 2016 10:09 AM
To: towertalk@contesting.com
Subject: [TowerTalk] question about a matching transformer

Date: Tue, 12 Jul 2016 20:20:57 -0400
From: "StellarCAT" <rxdesign@ssvecnet.com>
To: "tower" <towertalk@contesting.com>
Subject: [TowerTalk] question about a matching transformer


But there is a version of it ? shown in W2FMI?s book, that provides for a 2:1 match. And my initial thoughts are ? if I am using 2 monobanders and I can do 2:1 why would I not do it?


Gary
K9RX at arrl dot net

## If using 2 x monobanders, why not just use either the traditional method, with 70/75 ohm coax and relays..... or a simple L network, and relays. The L network is dead simple, just a shunt C from 50 ohm input to chassis..then a series coil from 50 ohm input connector to the 25 ohm output. Use some surplus NPO ceramic 5 kv doorknobs for the C ....and a small .25 inch OD cu tubing coil, for the coil. I have designed a few of these, like for 40 + 15m. And also a 50 to 16.66 ohm L network for 3 x yagis. Extremely low Q. Terminate the outputs with 50 ohm plugs..and sweep the input across the band of interest...dead flat..right out past each end. You cant blow up an L network. Typ deal is to parallel a few of the NPO caps to get the exact value required. Allen Bond at max gain systems had plenty of NPO caps a while ago. Then relays used to select top /bottom /both.

##  If you meant  2 x tribanders, etc, then disregard.

Jim   VE7RF


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