On Dec 9 2007, 7:15 am, "W7CXA" wrote:
I am looking for information on a 3 tube 75 meter am transmitter that was
around about 1958. Two of the tubes were 6146, one for modulator and one
for final. I cant remember what the oscillator was.

J. Andy Thompson
W7CXA
Yakima, WA


Back in the 50's there was a very popular TWO tube mobile transmitter
used by several mobile operators on 3995... Developed by Bob Carter,
W6NTU who lived up on the side of Mt. Hamilton near San Jose... It
used a12AT7 driving a sweep tube... Several of the fellows in addition
to a variant of sweep tubes, used a 6146 and an occasional 2E26 in the
final as well depending on available plate voltage... Half of the
12AT7 was the Oscillator, the other half was modulator... Carter
Modulation transmitters were very popular due to their simplicity and
performance. When loaded a bit on the heavy side, the audio sounded
quite good... Go to:

http://www.geocities.com/ResearchTri...13/carter.html

For a bit of History and a schematic of the transmitter... Remember
load that lil sucker fairly heavy with very little perceptible plate
dip for best audio results...

Good Luck de Grady K6IXA