John, For a two wire Beverage with two separate feed-lines (eliminating
the need for a relay a the feed point) it is important that the unused
feed point is terminated in the feed-point impedance to reduce
inter-coupling of noise and signals from the opposite direction.
Herb, KV4FZ
On 1/14/2015 8:44 PM, john@kk9a.com wrote:
The AY Technologies http://www.aytechnologies.com/ RAS-12 has momentary push
button switches for each radio and it has eight ports. It also has a
built-in preamp. This is a great product and it is very easy to use. I am
not sure if unused are terminated, why is that important?
John KK9A
To: cq-contest@contesting.com
Subject: Re: [CQ-Contest] Receive antenna switch
From: Herbert Schoenbohm <herbs@vitelcom.net>
Date: Wed, 14 Jan 2015 12:56:00 -0400
I use here a retired Dynair 12X1 passive video switcher. One nice feature is
that each unused RG-6 cable which runs to reversible two wire Beverages is
terminated. With feed line length equal to 1/2 wave (includes the cable
velocity factor.) the 75 ohm termination appears at the unused port at the
feed box. The only down side is that the push buttons move a connection on a
long bus inside and take a finger pressure. It would be great if someone
would market a desk top remote with momentary light touch switch or with a
computer interface. I have several Ameritron 8X1 along with the RCS 12 but
that only gives me 8 positions. it also does not terminate the unused ports.
The DX-Engineering 8X1, (RR-8B) which can be driven by the desktop RCS-12
has provisions for unused port termination, but to use a 5KW switch for a
bunch of Beverages seems a git of a over-kill. Hopefully something will be
on the market soon as there seems top be a need for something that will
control many Beverage inputs.
Herb Schoenbohm, KV4FZ
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