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[TowerTalk] Switching 450 ohm twinlead?

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Subject: [TowerTalk] Switching 450 ohm twinlead?
From: (Jim Reid)
Date: Fri, 06 Jun 1997 07:36:38 -1000
At 10:53 AM 6/6/97 PST, you wrote:

>Re all the recent posts about the RCS8V coax switch.  How is the best way
>to remotely switch 450 ohm twinlead?  I will have 3 arrays which are fed
>with twinlead.  I want to individually switch these to an outside remote
>matching unit...-snip- 

>Anyone have any
>experiences or thoughts on this?  Does anyone (Antenna Mart, Dunestar,
>etc.) make such a unit?

Aloha Henry,  

The relay you want and need is at Surplus Sales of Nebraska.  I just
bought two of them for switching my four v-beams planned for set-
up this Summer.  The perfect unit,  ceramic bases, is an Advance
Relay,  built by the Elgin National Watch Campany (years ago!).  

        Model AT/2C/115VA  DPDT

The ceramic base is 2 1/2 by 3 1/2 inches by 1/4 in thick.

The ribbon lead which carries each side of the 450 ohm 
circuits are about 1/4 inch wide and spaced 2 inches inside 
edge to inside edge of the ribbon.  Will certainly carry the
Pout of my 87A (but don't try hot switching!).

There can be no "bump" of impeadance using these that will amount
to any problem.  Only caveat is the use of 115VAC coils,  but
not a big deal. All the coax antenna relays etc. of the '50's
were also using 115VAC,  E.F.Johnson used them in the KW
Matchbox'x for example.  I paid $65 each for the relays,  and
was thrilled when I saw the quality of construction!!

Send an e-mail to Bob Grinnell at Surplus Sales, Nebraska:

and he can tell you how many he has left,  etc.

Good luck on your project!

73,  Jim, KH7M
On the Garden Island of Kauai

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