SINGLE SIDEBAND ON 17 METERS
After many happy months using my Double Sideband rigs on 17, I decided that I neeed to run a little more power. In good conscience, couldn't do this while using twice the needed spectrum, so I decided to make a technological leap into the 1950's by discarding one of the sidebands.
My SSB transmitter is loosly based on a G3YCC design that appeared in SPRAT #48.
I made extensive use of junkbox parts:
-- The crystal filter (5.173Mhz) came out of an old Swan 240 transceiver (junker) that I picked up in the Dominican Republic about 8 years ago.
-- Cabinet is from an old DX-40.
-- RF amp in the exciter was salvaged from a 20 meter CW rig I built in 1993 in the Dominican Republic. (It was modified for linear service.)
-- Low pass filter came out of a junker DX-60.
-- The front panel meter (an old Simpson) came from the junk box of the Crystal Radio Club in New York. I've been carrying it around in my junk box since about 1974.
The rig was built stage-by-stage on a number of small, separate PC boards. Construction was Manhattan style.
The carrier oscillator is crystal controlled. The LO for the mixer is a VXO. I now use 23.3XX Mhz rocks and can shift them about 24 khz. With two rocks I can cover most of the phone band.
The audio section consists of one LM-386 chip serving as mic amplifier. I use a D-104 microphone and use the gain control on the amplifier in the base to control the output level from the transmitter.
I use the rig with an outboard MOSFET linear based on a Ramseykit 20 meter amp. I can run the exciter at about 5 watts PEP. When I use it with the RAMSEY amp, I run the exciter at about 1 watt out and get about 15-18 watts PEP from the linear. I get very good reports on the signal quality. I've worked Australia several times "barefoot" (1 watt).
SCHEMATICS TO BE POSTED SOON.
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