[Heath] Problems with HW-101

[Bob G3OOU]

Hi Ken

Assuming that the VFO and band oscillator injection frequencies are 
correct then:

1. I would remove and examine the PCBs holding the inductors and test 
them on each band on a Q meter to ensure that the switches and inductors 
are behaving correctly on each band. If you have not got a Q meter then 
a GDO will have to suffice.

2. Make sure that the PCB surfaces and switch wafer surfaces and 
contacts are clean

3. Check that the 200pF is only connected on 80m (as I recall).

I sold my HW101 a few years back but still have an SB101 in good working 
order although it is non-standard as it has top band as an added band.

73

Bob

Bob F Burns G3OOU, G-QRP 6907, @BobFBurns
Crystal Palace Radio & Electronics Club: http://cprec.btck.co.uk/
Admin/sales site: http://www.g3oou.co.uk/ Technical site: www.qsl.net/g3oou

On 17/12/2020 20:18, Kenneth G. Gordon wrote:
> 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. It was
> complete. 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.
>
> 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, but weak,
> 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. 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
>
>
> _______________________________________________
> Heath mailing list
> Heath at puck.nether.net
> https://puck.nether.net/mailman/listinfo/heath