Sounds good to me Don, that's the only way I ever run it anyway, wide
open. Although I do have a variac in line it is to insure the line
voltage doesn't get too high. In my area it sometimes jumps as high as
125 volts and that would do the old power tranny no good at all. So, I
have a line voltage monitor and variac to keep the voltage to 115 - 117
volts.
Rick
Donald Chester wrote:
From: Rick Brashear <[EMAIL PROTECTED]>
Well, Brian, you are right, the 11 ohm dropping resistor is only in
series with the plate transformer... Of course, you're also right as
is Jim that this would throw the modulation bias off... As indicated
earlier, it's easy enough to operate with lower power by simply
adjusting the coupling. I say "easier" sometimes that rascal can be
real touchy.
It's best to run the BC-610 in the full power mode. HV protect is for
tuning up without risking damage to the final tube or other
components. Running the rig in HV protect will result in very poor
voltage regulation on the final, due to the series dropping resistor
in the HV xfmr primary. Running it with reduced loading will throw
the load impedance to the modulation transformer way off, with the
possibility of blowing the xfmr or arcing something over in the final.
The only proper way to reduce power would be to operate the plate
transformer from a variac or some other kind of autotransformer, to
provide a well-regulated source of reduced a.c. line voltage. Then
the modulator bias would have to be reduced, but that would require
extensive modifications, due to the combined audio driver
plate/modulator bias power supply arrangement.
Best to just run the BC-610 according to the stock instructions in the
manual, if you are not confident about doing extensive modifications
to the rig.
Don k4kyv
_______________________________________________________________
This message was typed using the DVORAK keyboard layout. Try it -
you'll like it.
http://www.mwbrooks.com/dvorak/
http://gigliwood.com/abcd/
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