[Heathkit] HW-101 Low Output on 40 Meters - another thing

[Kenneth G. Gordon]

Another thing you have to keep in mind is that the alignment of the 
driver grid and plate coils MUST be done in the order that Heathkit lists 
in the manuals; I.e. first 80, then 10, 15, 20 and lastly 40, in that order.

The reason is because of the somewhat unique way the coils are 
connected.

The coils for all bands above 80 are connected in SERIES, and that 
series string is then connected in PARALLEL with the 80 meter coil.

For 40 meters, that coil combination allows just barely enough range of 
the driver/preselector tuning capacitors to cover the entire 40 meter 
band, whereas on all the other bands there is ample range.

If any of the other coils for 20, 15 or 10 meters are out of alignment, 40 
will not work.

Lastly, you MUST set the driver/preselector control at the points listed 
in the manual during the alignment, EXCEPT for 40 meters.

What I have found is that you must set the VFO exactly in the center of 
the 40 meter band, or 7125, then set the driver/preselector control to its 
exact center, then peak the coils in the TRANSMIT mode.

Or, you could favor one end of the band or the other if you wished.

If everything is properly done, with a new set of finals, you should get 
110 watts output on 80, 100 on 40, 20, and 15, and between 80 and 90 
watts output on 10.

I might add that the SB/HW transceivers have enough range in both the 
driver/preselector and final amp tuned circuits to allow operation in the 
500 khz segments both above and below every band except 40 meters 
(and possibly above 10 meters)  by using an appropriate heterodyne 
oscillator crystal. I used an external heterodyne oscillator and fed the 
signal into the appropriate place in the circuit through one of the test 
points when I used an SB-101.5 for AFMARS phone patching into 
Vietnam and SEA about 40 years ago.

Ken W7EKB