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Re: Converter Protection

Take a clue from the eme'rs who been down that path too many times:
separate your Rx ant port from your Tx port.  If unwilling to do that then
using a sequencer is a must, else suffer the consequence.  How good are you
at replacing static sensitivity micro-sized GasFet's.  Also, been there and
done that {too much}.  Two of my xvtrs have transceive inputs and allow up
to 2w input. 

ALL my equipment is accessed either via sequenced switching or via
aseparate Rx port [mostly both].

>From: "Dave Metz" <Dave.Metz@mut1.muscanet.com>

>> From:          "Thomas Webb" <tmwebb@ionet.net>
>> To:            <amsat-bb@AMSAT.Org>
>> Subject:       [amsat-bb] Converter Protection
>> Date:          Tue, 5 Dec 2000 07:39:44 -0600
>> Having fried a Drake 2.4GHz converter a few months ago, I decided to
>> a Ramsey RFS-1 rf sensing switch to protect any future S-mode converters.
>> As a matter of scholarly inquiry, any better ideas floating around out
>> as to protecting mast-mount converters from inadvertent rf?
>Dear Tom,
>All of us will at sometime transmit into a converter or pre-amp.  One of the
>great advantages of being a home brewer is that the repair of your equipment
>is usually trival after one of these mistakes.  Been there, smoked it :-)!
>In practical terms your best protection is a squencer.  The ARRL 
>handbook has an excellent design for one.  I modified mine so when I 
>turn on the power for the "S" converter, I disable the two meter rigs PTT.
>This took only the addition of a couple of switching diodes as I recall.
>Turning on the power also activates the coax relay that switches the
>radio from its normal antenna to the converter output.
>So far this has worked perfectly.
>Another idea I have seen is to use a MMIC amp stage in line with the
>converter as a sort of RF fuse.  In other words, if there is an accident,
>you burn out the $1.50 MMIC (like a ERA-1 or MAR-1, etc) instead of
>the expensive guts of your converter.
>> Tom Webb, WA9AFM/5
>--73-- David WA0AUQ

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