Subject: Re: [Amps] SB200 on 6M
I'm converting a SB200 for 6M. What's the best configuration for the
Anti-Parasitic Choke?
Thanks
- Paul
## dunno. BUT if the 2 watt carbon comp resistors heat up, use more of
em in parallel,
OR use a small 7-10-15 watt GLOBAR. You can still buy the small
globars with wire leads
out each end..still on their website. Dunno what the min order is
though.
## On several 4-1000 HF amps from years ago, we would use five of
those carbon comp resistors
in parallel...end of heating problems.
Jim VE7RF
Having to use a high wattage resistor on such a small tube as a 572B means
you havent a clue about suppressor design, and simply use a generic brute
force method.
Carl
KM1H
### Use JUST enough L to make the suppressor work. If you use too
little L, it wont work. Use too much L
the resistorS will overheat, so it's a delicate balancing act. If you
use MOX type resistors, they have too much L
inside the resistor, so then you gotta put a cap in series with the
MOX, to cancel out the internal L of the MOX.
** Yeah, after I told you a few times. That was something I did back in the
late 80's or so and later copied by your buddy. Works OK for a kluge.
## A U shaped suppressor, made of cu or brass will work, as will heavy
gauge wire. 3 turns around a 2 watt CC will
also work, but the 2 watt CC will run hot.
** Not very well
## In an ideal world, IE: building from scratch, the chinese 572B
would not even be on my list....for a tube for 6m,
or even HF. A SB-200 6m conversion would be the ONLY time one would
use a 572B on 6M.
** Or several other 2-4 572B amps running 2 tubes. Ive even put a Clipperton
L on 6M with 3 tubes but not efficiently.
If 572B's were on hand then its worth the attempt at HB as are 813's and
some other oldies.
OTOH its easier using various tetrodes in GG such as the 4-125/250/400 as
they are often very cheap even NIB at hamfests.
## since doing all of this since 1972, and 38 amps later, I think I
have a reasonable concept of how all of this works carl.
** Its easy when you start with stable tubes and/or can copy what others
did. The thousands of HB 4-1000A amps are proof. The 813 and 4-400A are
other stable GG amps.
## two GS35B tubes will do an easy 5kw + on 6M......and no suppressor
required. Its already been done and pix posted..
on the yahoo amp reflector.
later... Jim VE7RF
** I dont think we should be bragging about a CB mentality power level on
here. Nor most of your other amps for that matter.
Carl
KM1H
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