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Old September 25th 07, 03:37 PM posted to rec.radio.cb,rec.radio.amateur.equipment,rec.radio.amateur.homebrew
james james is offline
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First recorded activity by RadioBanter: Sep 2006
Posts: 298
Default What happened to the SkyWave 2879ABTC?

On Tue, 25 Sep 2007 05:43:22 -0700, Telstar Electronics
wrote:

|On Sep 24, 2:42 pm, Frank Gilliland
|wrote:
| So you claim it doesn't work because one diode will "hog" the current?
| Well, that's the point! D1 "hogs" the current and establishes a fixed
| voltage for the base of TR1!!!
|
|As usual Frank you are missing the important point here. That point
|being that you can't simply parallel two diodes... and have them share
|currents. This would have to be done in order for any tracking between
|the two. The problem is that one diode will always turn on before the
|other... and take all current. Now I ask you... where is the sharing/
|tracking in that scenario? The answer is: there is no sharing/
|tracking... because one diode with the lowest drop will hog the entire
|current... and the other diode will be off. this is why the gentleman
|on the web page link that YOU provided says it that scheme works like
|crap. He's absolutely right!
|www.telstar-electronics.com
|
|-------------


Bovine excrement. Ever heard of equalizing of current through a series
resistance? Often called a ballast resistor. Used quite often in power
transistors where there are several base/emiter pn jumctions.

james