[Kenwood] TS850 and SB200

[Peter Markavage]

I've driven both my SB-200's with various Kenwood and Icom rigs over the
years and even my Flex 1000 and 5000 SDR rigs, and I never dip and load
the SB-200, but just tune for maximum output. If I need to decrease
drive, as for AM operation, it's all done at the transceiver. The only
meter junction I monitor in the SB-200's is the plate voltage. Both
SB-200's are still running the original tubes that were installed in 1969
and 1970. Unless you're running some screwy type antenna, or zip cord for
feedline, or trying to load an antenna for a frequency it was not
designed for, tune up with a SB-200 "Linear" amplifier is simple and
fast. And, I always hang a scope on my RF output from whatever rig or
amplifier, to monitor my transmitted signal.

Pete, wa2cwa


On Thu, 20 Nov 2008 09:16:22 -0600 Rob <k5uj at sbcglobal.net> writes:
It was always my understanding that the SB200 had 572s in cathode driven
grounded grid service and the tuning method was just like the 220:  Drive
the amp moderately, tune for max. output and go.  Pretty simple; no
peaking this or dipping that.  Am I mistaken?


73


Rob / K5UJ




On Nov 19, 2008, at 10:58 AM, Darrell Drake wrote:


 
However, my main concern in my original post, was the CORRECT tuning of
the amp.
You didn't say in your original post whether you had any experience with
tuning final tubes, be it for a tube radio or amplifier. I'm talking
about the dipping and loading of the amp's plate voltage and grid
current. Done incorrectly, i.e. too high a voltage/current, you've got
cooked tubes. The tubes can actually melt! You've got a 2400 volt power
supply in there!
 
If you want, I can dig up my Heath manual and e-mail a copy of the tuning
procedure to you.
 
Take Care and GL
 
Darrell,
VA3DG/VE3DDG
 
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