[Milsurplus] Just had to comment - chirp

[sbjohnston at aol.com]

I've noticed some possible confusion of the CW transmitter descriptions "Power Oscillator" and "MOPA". 

I use these terms in this way:
"Power Oscillator" = one tube, one stage, oscillator feeds antenna directly.   Can destroy FT-243 and later crystals, especially if optimized for maximum power output. Also can be challenging to get a good signal.   Examples:http://www.radioboatanchorblog.com/blog/homebrew-cw-6l6-vacuum-tube-transmitter-buildhttps://www.frostburg.edu/personal/latta/ee/6cl6xmtr/6cl6schematic.htmlhttps://onetuberadio.com/2017/03/25/1967-one-tube-cw-transmitter/https://www.frostburg.edu/personal/latta/ee/6cl6xmtr/6cl6schematic.html
"MOPA" = two tubes, two stages, oscillator followed by an amplifier.  Master Oscillator and a Power Amplifier.  Easier to get a good signal Examples:http://www.wd8das.net/TTTTT.htmlhttp://www.wd8das.net/dream.html
https://www.qsl.net/wd4nka/TEXTS/MOPAf.HTMhttps://www.qsl.net/k5dh/6ag7_6l6.html
https://www.qsl.net/k5dh/6ag7_807.html
Examples of simple rigs with with three stages (addition of buffer/multiplier between oscillator and power amplifier):http://www.wd8das.net/Raider/Raider.htmlhttps://www.wd8das.net/HW-16_transmitter.jpg
Speaking very generally, I find the ease of achieving a good signal improves with more stages.

Steve WD8DAS   

sbjohnston at aol.com   
http://www.wd8das.net/   http://af4k-crystals.com/   



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