[VHFcontesting] Icom AG-25 mast mount preamp

Jon Casamajor k6el at comcast.net
Sat May 29 21:05:32 PDT 2010

I bought a new  AG-25 preamp over a year ago and it never worked. I enabled
it in my IC-910H but it never worked on the tower, although it did work on
the bench.

I may have killed it with something over 100w but before I put an amp on
line, it still didn't work. I am refreshing my tower to be ready for the
June bash and have it here on my bench.took it apart and see nothing at all
burned up inside. Question is, what is likely to fail if it is hit with more
than the 100 watt limit?

I know it's better than any other preamp in the shack but I can't measure
how much if it isn't working. BTW, the 432 preamp on the same tower, feeding
the same radio works super but it's never had more than 65W through it. it
is also rated at 100w.

What would hooking up the preamp backwards do to it?  

Taking it apart, killed the purge but at least when I seal it up, our
humidity will be pretty low.33% now.  

The AG-25 is a really clunky design with the hard to reach, SO239
connectors. It's almost impossible to attach coax when mounted. Tiny
Japanese hands I guess.Clunky design




 73, Jon



More information about the VHFcontesting mailing list