[Icom] IC-761 s-meter bulb

[Paul Playford]

Ah yes, this is the transistor that kept blowing in my IC-765.  Turned out
to be poor ground connection between my station ground and tower ground.
Every time I turned my rotator (T2X) the voltage on the wiper of the
direction indicator potentiometer (in the rotator housing) came down the
center conductor of the antenna feed line and wiped the driver transistor
out.

I know this transistor was a very common failure in the 765 and I cannot
help but wonder how many of these failures occured because of Ham M rotator
housings not being bonded to the station (radio) ground.

In addition to bonding my tower ground to the station ground I also
disconnected the safety (green wire) ground inside the rotator control box.
This is a no, no, but it works for me.

de Paul, W8AEF

----- Original Message -----
From: "George, W5YR" <w5yr@att.net>
To: <icom@mailman.qth.net>
Sent: Monday, July 29, 2002 2:48 PM
Subject: Re: [Icom] IC-761 s-meter bulb


> Ron, I don't know how "dead" your TX is, but a common failure in the 765 (
> probably the same general setup in the 761) is the transistor that drives
> the driver and final stages in the output module.