As I mentioned, the varactor is equivalent to the Motorola MV1650. I
have a bunch as well left over from building VCXOs. :-)
David
On 10/19/12 3:37 PM, Rick Karlquist wrote:
Slightly off topic: the oscillator transistor has some 1854-XXXX
part number, but is actually a 2N5179 selected for some minimum
fT at 30 mADC collector current. When the oscillator starts up,
before the ALC takes effect, a fairly large DC current can flow
and some 2N5179's don't have enough gain to start oscillating.
The startup current isn't very well controlled. This info from
one of the 10811 designers.
I have a few 100 pF 10% glass varactors in my junk box if you
can't get them anywhere else. The spec is the same 2X capacitance
from 4 to 25 V, but a different XXXX-XXXX number because of the
10%. They are probably at least 30 years old!
Rick Karlquist N6RK
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