SB-303 alignment tips needed! Help!

[Ed Richards]

Hi Dave;

I have aligned several SB-303 with no difficulties. No extender boards
needed. Just follow the instructions in the manual. Sounds like you need
more than just an alignment. Radios don't get that far out of alignment
unless someone has screwed them up. Sounds like you may have a bad
component. Most likely a transistor. Pull the bandswitch shaft and take
out the boards to work on them. Not a big deal. I have done it several
times. If I ever need an extender board I plan on using a piece of ribbon
cable and put the male and female pins on each end. Take stage gain
measurements to isolate the defective stage. You can also use signal
insertion. Use a signal generator at the appropriate frequency and level.
Keep the S-meter near center. Insert a signal through a small capacitor
to the base, then the collector of each stage. You should have a higher
reading from the base than the collector. If you get the opposite, that
is a bad stage. You could have AVC problems too. Be certain you have a 50
ohm load on the LMO output jack. Use the troubleshooting guide in the
manual. Don't attempt to repair this receiver without a signal generator,
VTVM and manual. Good Luck.

73,

Ed Richards

On Wed, 17 Oct 2001 12:40:42 -0700 Dave Ellison <deellison at USWEST.NET>
writes:
> Hello all,
>
> I just acquired an SB-303 that is wildly out of alignment.
> It takes almost one VOLT of signal straight in to the antenna
> jack to hit anything above S5 on the meter!  It is stone cold
> deaf on all bands, and can only barely hear its own
> calibrator.  Matter of fact, the calibrator in the 303 can
> be heard across the room in my TS-520 with no antenna
> hooked to it, but the 303 is almost deaf to it!!  All the
> receiver does is play loud static and hiss (I've heard the
> 303's had a lousy noise floor, but that part is acceptable).
>
> I bought it on the idea it was working perfectly, so I wasn't
> anticipating having to do an alignment.  I've heard SB-303's
> are fussy to align - extender boards are essential (?)
>
> I'm lacking a manual, such extenders (rare, I know) and
> advice on SB-303's.  I only really do tube gear where
> everything is old and big.  Everything in here is much
> smaller :-)  My last alignment was an S-85 so this is clearly
> different in approach!
>
> Alignment tips anyone?  Manual anyone?  Extender anyone?
>
> Email with for-sale offers and sundry advice.
>
> Thank you,
>
> Dave WB7AWK
> www.Boatanchors.com
>
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