In a message dated 9/26/2007 8:14:05 P.M. Eastern Daylight Time,
sub1@rogerhalstead.com writes:
Were it me, I'd start with a search for articles on such conversions. They
may or may not be on the net. I don't recall seeing any in the ham
magazines, but I wasn't interested in doing a conversion until recently. As
I recall the ARRL Handbook and amplifier books deal with complete builds. I
don't know about QEX.
To my knowledge there has not been a conversion published on the Sb-200 that
I believe is worth trying. I tried them in the beginning, found I had to
blow on the dials when tuning up so I can find "the sweet spot" for everything
to come together, but then, there are some that will be satisfied with that.
What really needs to be done is to take a tried and true amplifier design,
such as the many written for 6 meter 3CX800 and 8877 tubes and simply adapt it
to the Sb-200. When the same principles are incorporated properly to the
Sb-200, you can and will have a nice easy to tune amplifier for 6 meters. You
will notice if you have any experience with an HF SB-200, that it will load
very smoothly on 80 and 40 meters, when you get to 10 meters it gets pretty
critical, can you imagine the tuning of the same amp at 50mhz if all the same
components are used? Not too good, yet 85% of the trash you will see on
SB-200 conversions is exactly that, add on 6 meters to HF. Do a good sound 6
meter only conversion and you will be a lot happier. No voodo magic needed.
Good luck 73 Lou
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