[Elecraft] Mostly OT: TS-820

[W3FPR - Don Wilhelm]

Tom,

I don't know about the TS-820S, but if the finals are run in linear mode for
both CW and SSB, you can safely reduce the drive without hurting anything.
If your TS-820 has a drive control, I would think it would be safe to use it
to reduce the drive.

OTOH, (just as a cautionary note) a few manufacturers used to run the finals
in class AB for SSB, but changed the bias to class C self-bias techniques
for CW (mainly to obtain greater output power in CW - but this was usually
only true for ancient boat anchors).  Some class C stages use the drive
power itself to develop the grid bias (using rectification using the grid to
cathode junction) - these designs will have runaway plate current if the
drive is removed or substantially reduced.  If you have fixed bias on the
grids for both modes, it is very likely safe to reduce the drive level.



73,
Don W3FPR

> -----Original Message-----
>
> Hello group,
>
> I'm not sure where else to ask this question. I can't seem to get anything
> but an answering machine at the Kenwood Amateur Radio Tech support Center.
>
> While waiting for a new K2, I would like to get on the air (after a
> considerable absence) with an old (but very good) TS-820S. The
> problem is -
> too much interference with the computer and TV at rated output. Since the
> neighbors are pretty close, I probably would interfere there as well.  I
> have done short tests at qrp levels with no interference.
>
> However:  Is it advisable to reduce the drive to qrp levels (for
> longer than
> short tests) without damage to the 6146 finals?
>
> Thanks,
>
> Tom, K0PXL
>