Bruce
> Drive the mixer LO and RF ports in quadrature using the same low noise source.
> Low pass filter the IF output and amplify with a low noise high gain
> amplifier.
> Look at the amplifier output with a spectrum analyser (e.g. sound card
> based spectrum analyser).
> Calibrate spectrum anal
WarrenS wrote:
>>> If they are off you don't need this kind of performance.
>>>
>> Not true, if the offset is accurately known then a stable oscillator
>> that has a frequency offset > 1E-9 is just as useful for calibration
>> purposes as one that has an offset of 1E-11 or less.
>>
>
John
Thanks, helpful and constructive points,
I'll try and comment on them all.
> Ordinarily two oscillators won't track that well in
> response to shared environmental conditions alone.
And I'm well aware of that.
I started by measuring their interactions, each both on their own independent
" ws", ">Bruce", ">>ws" ">>>Bruce" "ws" ">Bruce"
>> If they are off you don't need this kind of performance.
> Not true, if the offset is accurately known then a stable oscillator
> that has a frequency offset > 1E-9 is just as useful for calibration
> purposes as one that has an of
WarrenS wrote:
> ws reply to ">" Bruce's comments
>
>
>>> That calibration is linear over > than a 1 Hz (1e-7) offset range.
>>>
>> Whilst that may be true for your OCXO, this is certainly
>> not true for every ocxo one may wish to measure.
>>
> It is not the measured OSC that need
saying angrily "using a GPS on a
plane is illegal".
Nonsense...unless their own rules prohibit such use, in which case
you are legally obliged to comply. There is no blanket (ie:
government) rule against them.
It is up to the airline; in the past year I've flown a number of
different
