[Heathkit] SB-303 no recieve HELP!!!

[Bill Cromwell]

On Thu, 2012-09-27 at 22:48 -0400, Dan Pividal wrote:
> Have an SB-303 Heathkit.
> Turned it on and no recieve on 80 meters.
> All other bands ok.
> After 10 minutes 80 came on strong all by itself.
> Turned off unit and when I turned it back on a few hours later 80 meters dead again.
> After 10 minutes of rig being on 80 meters came up.
> turned rig off and went to bed.
> Next morning rig dead on all bands and has never come back.
> S-Meter only shows a less than 2 on all bands.
> None of the bands peak with the pre selector.
> I have no extender boards for the unit to trouble shoot.
> I have cleaned all contacts and checked for continuety.
> I have looked in the manual and no trouble shooting hints for this problem.
> If anybody can at least point me in a good direction or help me brain storm I would be mos greatful.
> Thanks 
> Dan/N4VET


Hi Dan,

I don't have a 303. I do have several heterodyne radios. I am suspecting
your heterodyne oscillator board and the alignment there. I'm
particularly suspicious about that because of the 80 meter band being
the first to show signs of trouble. A single band always points there.
Try doing a good alignment of that board as the first step. Check
voltages there, too. A resistor or cap may be dying (or dead now) and
drifting excessively with temperature.

Make sure you have good clean ground connections *everywhere*.

Check or even substitute a tube in place of the heterodyne oscillator
tube. Now I'll probably find out the 303 is solid state or something
<evil grin>.

Good luck.

73,

Bill  KU8H