[Icom] re pa output trans in Icom transceivers

[Dana Hoggatt]

The most thorough and methodical way to diagnois these
kinds of problems is to follow the signal path through
the device, stage by stage, until you discover a stage
with a problem.  You then fix that stage and continue
on down the line.

In the case of the 746, that signal path splits in two
before the PA stages.  That implies that you've either
blown both PAs (possible but not likely), or there's
something wrong earlier in the path.

Yes, the procedure is tedious ... but you're almost
certain to find the problem.  So buy a service manual
and borrow an oscilliscope; then get cracking.  And
when you do find the problem, please let us know.  'I'
for one, am very curious.

Good luck.

Dana, KB9SSS



On Sep 17, 10:57pm, "Jimmie Sowell" wrote:
} Subject: Re: [Icom] re pa output trans in Icom transceivers
} 
} If this is true
} 
} "> In the IC-746, there are separate PA's for HF/6m and 2m. Each PA uses a
} > matched pair of 2SC2694's. The drivers are matched pairs of 2SC1972's, and
} > the pre-drivers are 2SC1971's (separate HF/6m and 2m chains)."
} 
} then why did my HF/6 and 2 meters all go out at the same time?  Could I have
} a problem other than the PA's?  Anybody have other ideas before I send it
} off to ICOM.
} 
} 73, Jim