[amsat-bb] Re: Receive Pre-Amps for 70cm

Mike Ryan mryan301 at comcast.net
Tue Feb 7 19:56:04 PST 2012

I second the comment about getting a switched one. Unless you have a 
dedicated RX or have disabled the TX, you will certainly pop a RX only amp. 
Its just a matter of when. Happened to me twice before admitting my 

I've had very good luck with the ARR switched amps. I have two for 70 cm 
(one for the shack and one for my Arrow) and a 2M version as well. If the 
unit is to be in the attic, you can save some money by going for the inside 
25 watt switched model (SP432VDG). Just don’t exceed the 25 watts. Also be 
aware that the FETs in these amps are sensitive, even on a switched model. 
Make sure your rig is completed powered off and your body grounded (to bleed 
off static electricity) before connecting or disconnecting antenna 
connectors.   Its tempting to save a trip to the shack by leaving the rig on 
and do a quick swap, but don’t do it :(


Date: Mon, 6 Feb 2012 15:40:37 -0600
From: "Alan P. Biddle" <APBIDDLE at UNITED.NET>
To: "'PETER SIMONSEN'" <pureenduro at msn.com>, <amsat-bb at amsat.org>
Subject: [amsat-bb] Re: Receive Pre-Amps for 70cm
Message-ID: <86B0819F8E944465B5B0C98010D7AAB7 at WA4SCA>
Content-Type: text/plain; charset="us-ascii"


A 70 cm preamp is always useful! There are a lot of them out there, but my
experience is that ARR and SSB Electronics make the best. Definitely not
the cheapest, though.



Be certain to get one which is RF switched, and which will handle your rig's
power. No matter how careful you are, you WILL transmit into it someday.
Been there, done that.

You will need to split your single antenna jack on the rig to two lines.
Almost any diplexer gives 50 db+ separation, but there are a few which are
only 30 db or so. Worth checking.



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