Re: OT: The Colpitts mystery

Posted by Phil Kane-2 on Apr 28, 2020; 3:06am
URL: http://elecraft.85.s1.nabble.com/Voltage-drop-in-DX-Power-to-K3-tp7660188p7660266.html

On 4/27/2020 11:03 AM, Fred Jensen wrote:

> What was it with the FCC and the Colpitts oscillator schematic on the
> exams in the 50's/early 60's?  It was on my General ['54] and Extra
> ['56] exams, and practically everyone else I've asked says it was on
> theirs too.  There are other oscillator circuits of the day.  Colpitts
> uses capacitive feedback which is somewhat more stable than a Hartley
> with its "Tickler Coil," but the FCC seemed fixated on the Colpitts for
> some reason.  The schematic and operation of a dual-triode 1-shot was
> also popular.

They had to pick one of the two, and the rest was inertia.

The Second Telegraph exam that I took about 8 years ago had the same
questions as the one that you took "back when".  Who remembers
"transconductance"  :)

73 de K2ASP - Phil Kane
Elecraft K2/100   s/n 5402

From a Clearing in the Silicon Forest
Beaverton (Washington County) Oregon
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