-----Original Message-----
From: Carl
Sent: Monday, June 03, 2013 11:27 AM
To: Jim Thomson ; amps@contesting.com
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.
## 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.
## 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.
## 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.
## 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
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