Need help in tracking down issue with Heath SB102 on 40 meters

[Bernie Murphy]

I am at a loss to figure out why my SB102 has about 5 db loss on receive and 
won't transmit at full power on 40 meters.

I am not sure of the original status of this radio as I just purchased it 
recently; the seller claimed he did not test it.. It may have never worked 
properly when it was assembled; the challenges of kits.

Using my signal gen with 100 uv into the antenna jack, the meter reads 
S-9+5dB or better on all bands except for 40 meters where the signal reads 
S-8.5 or so.

On transmit, the rig will not load beyond 160 ma and only puts on about 30 
watts on 40 meters into a dummy load. All other bands, the rig puts out 
double that power or better, except for 10 meters (which is to be expected). 
On all other bands, the transmiter loads to 250 ma.  Power ouput readings 
where taken with a Collins Wattmeter (there have been reports that these 
meters read low as they age).

There is no grid drive reading on 40 or 80 meters according to the SB102 
meter. Lots of grid drive on all other bands.

I've tried the following:
1. Cleaned all the switch wafer contacts and in particular the driver grid 
and driver plate wafer switches. These are really hard to clean as the 
clearance is minimal.
2. Using an ohmmeter, metered the driver grid and driver coils and all looks 
well
3. Resoldered the traces involving 40 meters on the driver grid and driver 
plate boards going to the 40 meter coils
4. Resolderd the 40 meter driver grid and driver plate coils where the 
windings are soldered into the coil holder
5. Swaped another 6HS6 RF amp tube from another working SB102; got a bit 
more gain on receive (about 5 dB)  on all bands but of course, did not fix 
the transmit issue.
6. Tried another set of 6146s (should not make a difference) and it did not.

Anyone run into this type of issue with the HW100/SB100 series radios?

Any suggestions would be most welcome.

Sounds simple to fix but this one has me stumped ...

73, Bernie 

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