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Old September 27th 06, 01:10 PM posted to rec.radio.cb
Frank Gilliland Frank Gilliland is offline
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First recorded activity by RadioBanter: Jul 2006
Posts: 432
Default Thought this was puzzling...

On 27 Sep 2006 04:42:20 -0700, "Telstar Electronics"
wrote in
om:


Frank Gilliland wrote:
The diode method works, it's just not idiot-proof so it's no good for
a production CB amp.


Well, I claim it doesn't work... unless you want to tell me how you can
parallel two diodes together... without any ballasting... and have both
of them turned on. That's essentially what that circuit is doing.



No, it's not. I explained this before but apparently it flew over your
head. So I'll try to make it a bit simpler for you: Instead of having
a single diode checking the heat of two transistors, this guy used one
diode on -each- transistor. They may be wired in parallel but they are
-not- expected to work at the same time. Why? Because the bias will be
fixed by the diode with the lowest Vf, which will be the hotter of the
two diodes (Vf decreases as temperature increases).


Unlike you... I have certainly tried it before. It doesn't work... for
the reason I stated.



Well Brian, I -have- used the circuit before, in several different
variations, and yes it -does- work.