10-06-2013, 02:09 PM
(10-06-2013, 01:03 PM)pwdrive Wrote: Internal shot of a TE 57, looks like an ordinary tuning gang?
http://www.radiomuseum.org/r/lafayette_g...te5_9.html
Lawrence.
Almost certainly: two insulated stators, one common rotor, electrically connected to the metalwork sub-chassis.
This choice of capacitor is quite common for GDOs: the common 'earth' of the capacitor is sometimes connected to 0 v./ common / R.F. ground via a decoupling capacitor. What I don't quite understand are those designs that not only do that, but also centre tap the coil to R.F. / 0v. as well: only one 'R.F. ground' is required: producing two is asking for trouble.
As for commercial vs. home-brew GDOs, I've always found that home-brew designs usually outstrip commercial designs, in terms of performance, by a substantial margin. I have an early Heathkit GDO and in terms of sensitivity it leaves a lot to be desired. And the internal construction is quite poor, too.
Somewhere in my 'W-I-P box' I have a couple of experimental GDOs under development: I really must get on with them: perhaps this thread will now give me the final push I need.
Al.