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Old 12th Mar 2018, 1:26 pm   #8
G4WYZ MikeyP
Triode
 
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Join Date: Nov 2012
Location: Chorley, Lancashire, UK.
Posts: 21
Default Re: Racal 9081 phase detector problems.

Thank you for the very comprehensive info Peter.

Results
Once level shifted the outputs can then be used to determine if the frequency selection is in band or not, and if it is too high, or too low:-

Q0 is used for band edge detection on 5, 10, 20 kHz channels
Q1 is used for band edge detection on 6.25, 12.5, 25, 50 kHz channels
Q2 is used for band edge detection on 15, 30, 60kHz channels

Output is LOW when in band, high when outside of band.

Mine are still LOW even out of the band.

On reflection I've had an issue with the 1/2 octave oscillator before. This tends to confirm the ROM is faulty.

Can't really decide to continue with this as I just discovered another fault the 5MHz hi-stability oven is 2kHz off frequency adjustable to adjust as well an issues with the modulation.

Just a matter of interest is the repair board available?

Mike
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