[amsat-bb] Re: Devices in Icom preamps AG-25 AG-35

[George Henry]

I should have offered this first:  before suspecting the preamps, did you 
enable preamp control for each band in the 910's "SET" menu?  Preamp control 
must be enabled before the front panel P.AMP button will switch power to the 
preamp.  Also, there must not be anything inline such as an SWR meter, 
filter, or anything else that might block DC on the coax.

If you hook the preamp up to the rig with a short jumper cable, you should 
head a noticeable relay click from the preamp when you press & hold the 
P.AMP button.

George, KA3HSW


----- Original Message ----- 
From: "Mark L. Hammond" <marklhammond at gmail.com>
To: <amsat-bb at amsat.org>
Sent: Wednesday, March 17, 2010 5:29 PM
Subject: [amsat-bb] Devices in Icom preamps AG-25 AG-35


> Hello all,
>
> We either had two bad preamps to begin with, or they became casualties 
> during transport to K4T, but regardless--the Icom preamps we took appear 
> to have bad GAsFET devices in them.
>
[snip]