[AMRadio] Matching a 100 watt PA am to drive 833'S

DOXEMF at aol.com DOXEMF at aol.com
Wed Jan 5 01:24:58 EST 2005

Hello Don (s)
I have that Gates driver deck with I believe an intact driver.
I also have most of the manual possibly for that transmitter.
The driver received feedback directly from the finals to help compensate the impedance shifts you mentioned Don.
What might be of interest tho a bit over kill is the Gates 5kw
audio driver deck that used a quad of EL34's or 6550's to drive the pair of 2500 modulators. Now that has drive!
I would guess that the reason for eliminating the 845s is due to their high cost.
A pair of equally expensive but more commonly found 211-VT4C
triodes would work in place of the 845's to the best of my knowledge.
Some of the old PA amps also had a 100 volt output winding that might be adaquate for drive. Not sure the actual Imp.or availability of center tap. Typically a mono bridged solid state stereo amp can approach 100v levels as well with some mfg's claiming 100V line capability in that configuration.

If info from or a copy of the 1K manual is needed please E-mail me and I will try to get one made up thats readable. This one was worn out by many engineers use and am not sure if it's complete.I believe the schematic is intact tho taped together.
I also have most of the Iron for the 1K tramsmitter with at least one LV powersupply transformer burnt. Not parting with the 10v filament transformers. need them for my 813's.

Bill KB3DKS/1

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