SB-101 on 40

[Steve & Anne Ray]

The first thing to check is that the driver capacitors track together (they
are the ones driven by the rubber belts).  On 40 meters this is critical.
2nd check to see if the R-202 the 10K resistor connected between C111 and
pin 2 of V5a is replaced by a jumper wire.  (This was a Heath Service
Bulletin). This resistor was removed in the SB-102, but left in the HW-101,
I do not know whether it was in the SB-101.   It runs across the circuit
boards.   Under no conditions remove T-102 the 6.8 MHz trap removal will
insure you will transmit a spur.  Years ago this was considered a solution
to low drive 1. It does not solve the problem of low output on 40 Meters
and 2.  You guarantee a spur on 6.8 MHz the 2nd harmonic of the carrier
oscillator.

If none of these solve your problem.  EMail me and I will get into some of
the more devious causes.

----------
> From: Stewart D Lyon <slyon at SPACEVECTOR.COM>
> To:
> Subject: SB-101 on 40
> Date: Friday, August 08, 1997 5:23 PM
>
> HELP on SB-101.
>
> I have resurrected my 29 yr old SB-101 and really got it working great
> except for one thing: low drive on 40 meters.
> The set is very sensitive on receive and is able to peg the grid current
> meter on all bands except 40 mtrs (where I want to operate). There I can
> barely get a wriggle out of the grid current at full on CW/MIC Level when
in
> Tune and very little ALC action on LSB -- even when practically shouting
in
> the mic.  Sometime in the distant past, I installed the 6HS6 mod and the
> "switch tuning cap" mod from QST but I don't think that has anything to
do
> with the problem.
>
> I have replaced the 6146s and the 6CL6 driver and have gone over both the
> receiver and transmitter alignment a dozen times to no avail.  What is
> really puzzling is that the problem is only on 40-transmit.
>
> Does anybody have a clue as to how to fix this problem?? I would really
like
> to get this set working because a)it brings back my youth and b)it is
more
> sensitive & quieter than my Kenwood TS440.
>
> Thanks in advance and 73;
>
> Stu Lyon, W6CUX
>