[Elecraft] OT: The Colpitts mystery

[David Gilbert]

The Colpitts oscillator was regarded as being the most stable 
oscillator, which is why it probably was always there, and it was indeed 
on my test in the mid-60's.  But the Hartley oscillator was also on my 
test if I remember correctly, as was the tuned-plate tuned grid 
oscillator.  If I remember correctly, I had to identify each of at least 
three oscillator types.  The series tuned Colpitts (aka Clapp 
oscillator) might have been there ... maybe the Pierce crystal 
oscillator also.  I remember that I was required to be able to tell a 
bunch of them apart.

Dave   AB7E


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