On Wed, 23 Sep 1998 14:32:06 -0700 (PDT) david wintheiser
<w0opw@yahoo.com> writes:
>
>I cranked up my old SB-200 with the Yaesu FT-900 driver
>and discovered that the FT-900 power was reduced to 50 watts. This
>was on CW !!. Removing the ALC line brought the drive power back up
>to 100 watts.
And leave it off. That ALC circuit was designed for tube exciters and is
not compatible with the SS gear. Anyway your 990 has a real good
internal ALC and it should keep the SB-200 from overdrive problems.
Just be sure to load the 200 up to full output with 100W (700-800W with
good tubes) and then use the ALC control on the 990 to keep the 200 voice
peaks to about 60% of key down.
> Does anyone have experience with this anomoly on SB-200's ??
> Rich, if your monitoring this, I bought 2 of your kits for 572b's
>this spring but can't remember what you
>recommend for Cathode swamp resitors instead of ALC.
Dont bother; you wasted a few bucks......a 990 can not hurt a SB200. The
only "if" I am aware of is with some Svetlana tubes which tend to be
rather squirrely in any amp......particularly a FL-2100.
73 Carl KM1H
Amplifier Repair and 6M Conversions Our Speciality ( SB200 and 220 series
in particular). Ask for a free flyer.
>
>
>
>
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