Not very far from truth, for old transponders, but I really whought with mode-s those old transmitters should be scrapped now. Obviously not :)
The older transponder designs often incorporated a tube that was a kind of high power oscillator, built into a precise cavity and tuned to 1090 MHz with a fine threaded screw, then a fat blob of sealing paint to secure it, that's all. So, yes, basically a LC oscillator. > Perhaps G-LSAC uses an L-C oscillator rather then a crystal in it's wirelesses :-) Yep :) Perhaps some older designs were modular, the transmitter stayed the one from the seventies, just a new coder was attached?! Ralph.
