[Amps] SB-200 on WARC

[Vic K2VCO]

Thomas Tanbäck wrote:
> Is it safe to tune up a Heath SB-200 on 30-17-12 M bands, in view of the HV 
> rf choke?
> I assume the input bandpass filters is proper adjusted for this bands...

Possibly not on 17 M.  But in any case you can check this with a grid 
dip meter.  Temporarily solder a jumper across the choke and then (with 
power off, of course) look for a resonance.  If it is within a MHz or so 
of the frequency at which you plan to operate, you may have a problem.

If you have an antenna analyzer you can accomplish the same thing by 
disconnecting the plate side of the choke and (no jumper this time, 
obviously) measuring the impedance of the choke.  Look for dips 
indicating series resonances.

-- 
73,
Vic, K2VCO
Fresno CA
http://www.qsl.net/k2vco