[Heathkit] Problems with HW-101

[Kenneth G. Gordon]

Hello Gary and all:

I am working on an HW-101 for a friend and have run into a problem I have
not seen before. I am not sure how to address this, so I am asking for
advice here.

But first some history.

My friend bought the HW-101, with an HP-23 and a speaker, at a garage
sale for about $50.00. It was complete, but very dirty. He cleaned it up quite well. He later 
found and bought a Heathkit desk-microphone at another garage sale.

I completely rebuilt the HP-23 and it is completely up to spec.

I have cleared many problems with the HW-101. 

The first one was that the VFO would competely stop working after a short
warm-up period. I fixed that by replacing the VFO's FET, and replacing the
VFO's voltage regulator. The VFO is now stable and reliable.

Then, when I attempted it align the rig, following the manual's
directions, I found that I could not find any peak on either the grid or
the plate coils for the driver on 10 or 15 meters, and the peaks on 40 and
20 were weak, probably due to the fact that all those coils are in a series-parallel 
arrangement.. 

The coils on 80 meters appeared to peak correctly.

I replaced the driver and final amp tubes with new ones.Then, when testing
for power output, if the rig was cold, power output on 80, 40 and 20
appeared to be close to spec, although a little low, but as the rig warmed up, power
output would drop to zero.

Replacing the IF amplifier tubes appeared to fix that drop-out problem,
but things are still not correct.

I checked the heterodyne oscillator alignment, and all of those appear
correct. I reduced all of those to -3.5 VDC at the TP. Although the manual
calls for lower voltages, and a maximum (apparently) at -2.0 VDC, I didn't
think the higher voltage would hurt anything, so I left that alone, as
long as all were equal. I also tuned them all down on the slow side of the
peak as the manual orders.

Using the calibrator, I can get a reading of well over S-9, like 20 dB
over S-9, on 80, but only S-3 on 40, and no S-meter reading at all on 20
and up, although I can hear the calibrator on all bands.

Power output in TUNE on 80 is close to 100 watts, although in the past, on
other HW-101s and SB transceivers I have worked on, the NORMAL power
output on 80 has always been 110 watts. And this power output is only
available with the MIC/CW LEVEL pot all the way up

I can get about 75 watts on 40 and 20, but only 5 to 10 watts on 15 and 10
meters.

I have carefully examined all the wiring and soldering and can, so far,
find no faults in either.

What is bugging the heck out of me is that I cannot figure out WHY I
cannot tune the driver grid and plate coils at all on 15 and 10 meters.

As I run the slugs further into the coils, the signal from the calibrator gets louder, but never 
comes to a peak.

Everything LOOKS correct there. All the coils appear to be the correct
ones, but unless I can get the alignment done correctly, both power
output, and receiver sensistivity will be way low.

Has anyone run into a similar problem in the past, what did you find, and
how did you correct it?

Ken W7EKB