Re: [TenTec] Omni 5 Feedback

["Mike Hyder --N4NT--" <Mike_N4NT@embarqmail.com>]

Seems in my younger day what you describe was often caused by a bad cathode 
bypass capacitor.  Probably there are similar things that could go wrong 
today.
73, Mike N4NT

----- Original Message ----- 
From: "Dr. Gerald N. Johnson" <geraldj@weather.net>
To: <tentec@contesting.com>
Sent: Monday, September 28, 2009 11:20 PM
Subject: Re: [TenTec] Omni 5 Feedback


> On Mon, 2009-09-28 at 15:15 -0400, Howell, D. Haney wrote:
> > My trusty Omni 5 has been under wraps for a few months.  When I fired it 
> > up
> > recently I experienced motorboating and rumbling feedback though the
> > speaker.  As the old hamfest saw goes, it was working fine the last time 
> > I
> > used it!  Any suggestions where to start troubleshooting?
> >
> > Haney
> > k2xn
> Usually motor boating and rumbling feed back are a sign that the power
> supply bypass electrolytics have gone nearly open or have gone way down
> in value. That's not only the main power supply but the various supply
> voltage busses on the board.
>
> But for a first step, to make sure the board grounds are good, tighten
> all the PC board mounting screws. Then in Tentecs wiggle the cable
> connectors. Or pull them off and apply a tiny bit of DeoxIT to each pin.
>
> 73, Jerry, K0CQ