Re: OT: The Colpitts mystery

Posted by George Danner-2 on Apr 27, 2020; 10:49pm
URL: http://elecraft.85.s1.nabble.com/Voltage-drop-in-DX-Power-to-K3-tp7660188p7660263.html

It was on the 2nd phone as well!
Not sure if it was one I had to draw or just identify.

My recollection is that the 2nd phone was much much harder than the present
Extra.
My commercial licenses were 1959. My Ham license is 2007.

73
George AI4VZ



-----Original Message-----
From: Fred Jensen
Sent: Monday, April 27, 2020 2:03 PM
To: [hidden email]
Subject: [Elecraft] OT: The Colpitts mystery

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.

73,
Fred ["Skip"] K6DGW
Sparks NV DM09dn
Washoe County

On 4/26/2020 7:28 PM, N4ZR wrote:
> As for the licensing tests, did you have to draw a Colpitts
> oscillator? IIRC, that was on my General exam in 1955.

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