In a message dated 8/2/2006 3:49:29 P.M. Eastern Standard Time,
g3rzp@g3rzp.wanadoo.co.uk writes:
That deals nicely with the output side. But 811s and 572s have very long
grid leads, which make them awful bloody things at 30, let alone 50MHz. So
personally, I wouldn't touch them with a barge pole (as the saying goes) on 6.
I
suppose you could series tune the grids to resonance, but I have doubts about
the resulting efficiency at the end of the day. The spacing is enough for, I
suspect, transit time to start coming into play, as well as the gain
dropping because of cathode lead impedance.
73
Peter G3RZP
An SB-200 running a pair of 572B tubes will make a good 700 watts output on
6 meters. As long as it is run in SSB and the proper type of parasitic
suppressor is used, it will be stable with proper tune up. Granted, they are
troublesome if you do not finesse properly, however they can be coaxed to work
just fine on 6 meters. Lou
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