[amsat-bb] Re: pre amp help..

[Bob- W7LRD]

Ahhh another AO-40 comment.  I used a old and still have in operation an old TS-700A  2M xcvr with the tx disabled.  This was, and is my designated S band receiver.  Speaking of S band when will AO-51 be back in that mode.  If even for a few days, it's fun to play with that stuff. 

73 Bob W7LRD 
----- Original Message ----- 
From: "Greg D." <ko6th_greg at hotmail.com> 
To: k7trkradio at charter.net, amsat-bb at amsat.org 
Sent: Wednesday, February 16, 2011 9:56:50 PM 
Subject: [amsat-bb] Re: pre amp help.. 


As others, SSB Electronics model that is RF switched.  I *have* transmitted 100+ watts into it, though not on purpose, and it works just fine.  I got the RF switched model as a "just in case" bit of insurance, and am glad I did. 

It's been reported here a few years ago  that sometimes there's a little "burp" of RF that squirts out when a transceiver is powered up.  Seems unlikely , but if so, maybe that did it? 

If I recall, the discussion was about people frying their AO-40 S-band down converters by accidentally transmitting into them.  An somewhat less certain recollection is that someone came up with a simple circuit that would clamp the RF to a more forgiving, if not totally safe level.  As an alternative to an RF switched preamp model, perhaps a stroll through the archives might net a different solution. 

Good luck, 

Greg  KO6TH 



> From: k7trkradio at charter.net 
> To: amsat-bb at amsat.org 
> Date: Wed, 16 Feb 2011 13:59:41 -0800 
> Subject: [amsat-bb]  pre amp help.. 
> 
> I just sent my ARR pre amp back to ARR for repair for the 3rd time ! 
> 
> (pretty sure I did not tx through it ) 
> 
> What are people using for pre amps. I only see the Mirage as an alternative. 
> Any other choices. I'm kind of disappointed in ARR products. 
> Is there a pre amp that you can tx through preventing accidental frying? 
> 
> Any thoughts appreciated 
> 
> 73, Ted, K7TRK 
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