[Heathkit] Problems with HW-101

Thu Dec 17 20:25:26 EST 2020

Ken, common experiences with the 10x series!  Here is what I have found in my numerous restorations:  (suggestions in CAPS for easy interspersed reading - I'm not shouting).
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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..

CHECK THE WAFER FINGERS FOR CONTACT, AND VERIFY THE ROTOR IS NOT 180 DEGREES OUT OF PHASE (CHECK THE NOTCHES WITH THE BANDSWITCH SHAFT OUT).

The coils on 80 meters appeared to peak correctly.

THE COILS MUST BE PEAKED IN THE CORRECT ORDER AS DESCRIBED IN THE MANUAL.  SINCE MULTIPLE COILS ARE NOT WORKING, THE BOARDS SHOULD BE PULLED AND THE COILS CHECKED FOR CONTINUITY AND PHYSICAL BREAKAGE, OR A SOLDER SHORT ON ONE OF THEM.

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.

TRY SETTING THESE TO -2.5 VDC ON THE SLOW SIDE OF THE PEAK FOR ALL BANDS.  LOWER READING ON ANY BAND INDICATES A PROBABLE LOW ACTIVITY CRYSTAL.  USUALLY THE 10 METER XTALS ARE THE ONES TO GO FIRST - ESPECIALLY THE 37.395 FOR 29.5 MHZ.  YOU ONLY NEED THE 29.0 XTAL FOR 10 METERS FOR THE PLATE/GRID COIL ALIGNMENTS.

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.

YOU SHOULD GET 30 OVER S9 ON 75, THEN DOWN FROM THERE DUE TO THE HARMONICS OF THE 100 kHz CALIBRATOR DROPPING OFF IN AMPLITUDE AS YOU GO UP IN FREQUENCY.  IF THE COILS TUNE, THIS WILL SHOW UP AS BETTER CAL SIGNALS.

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

POWER SHOULD PEAK AT 75% OF THE CW POT TRAVEL.

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

I'M SURPRISED YOU GET THAT MUCH OUT ON 40 AND 20 WITH THE 10 AND 15 COILS NOT PEAKABLE - COULD BE OSCILLATIONS IN THE FINALS YOU ARE TUNING.  MONITOR YOUR EXPECTED
TUNE FREQUENCY ON A SEPARATE RECEIVER FOR EACH BAND.

80/75 WOULD BE THE HIGHEST, SINCE THESE ARE PEAKING PROPERLY AND ARE FIRST IN THE SERIES CHAIN FOR THE DRIVER GRID AND PLATE CIRCUITS.  SHOWS YOUR RIG IS CAPABLE OF TOP POWER IF/WHEN THE OTHER COILS START TO PEAK CORRECTLY AT THE PROPER PRESELECTOR SETTINGS WHEN SET 200 kHz UPSCALE FROM THE LOWER END OF THE LMO (.2, .7 SETTINGS).

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.

YOU MUST SOLVE THIS ONE FIRST!  CHECK THE COILS FOR BREAKS OR PHYSICAL DAMAGE, AND POSSIBLY BEING "TRICKED" BY A SLUG WHICH IS ACTUALLY BROKEN AND NOT REALLY TURNING.  ALSO THE NYLON HEX TOOL MUST BE IN GOOD CONDITION - ONCE IT "CLICKS", YOU ARE SOL WITH THAT SLUG.  SLUGS EASILY REMOVED USING #3 OR #4 LONG ROUND HEAD SCREW AND NUT TURNED DOWN ON THE SLUG, THEN USE A SCREWDRIVER TO TURN IT OUT INTACT WITHOUT DAMAGE TO THE COIL FORM.

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

SOMEONE MAY HAVE REPLACED A BROKEN SLUG WITH ONE OF WRONG OR OPPOSITE FERROUS PERMEABILITY.  THESE SHOULD BE ABOUT 1/2" LONG AND DARK GRAY - NOT LIGHT GRAY.  1/4" SLUGS WILL NOT WORK.

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.

MAKE SURE THE 3 SLUGS IN T102 AND T103 ARE ALL PEAKED IN THE IF.

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

Ken W7EKB

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End of Heathkit Digest, Vol 199, Issue 1
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