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Switch626

Joined: Fri, Mar 18th 2016, 05:04 Roles: N/A Moderates: N/A

Latest Topics

Topic Created Posts Views Last Activity
Tube Ratio Detector Theory Nov 21st 2020, 23:25 2 2,165 on 22/11/20
Setup to See S-Curve in FM Demodulator Nov 7th 2020, 17:18 3 1,962 on 7/11/20

Latest Posts

Topic Author Posted On
Tube Ratio Detector Theory Switch626 on 21/11/20
I found this schematic of a tube/valve ratio detector at http://www.r-type.org/addtext/add059.htm. Does this circuit work during only one-half of the IF cycle. What are the current paths above and below resonance? It's an intriguing circuit and I seem to be missing one thing to make it click.
Thanks all for any help.
Setup to See S-Curve in FM Demodulator Switch626 on 7/11/20
Hi Bill, Yes, I am using a sweep gen,
Setup to See S-Curve in FM Demodulator Switch626 on 7/11/20
Hello all,
I was doing an alignment in a FM radio, your standard 88MHz-108MHz receiver. I completed the alignment but then thought I would see what a S-Curve looked like. I am injecting the FM signal into the base of a transistor (have a capacitor in series) that feeds a ratio detector tuned to the 10.7MHZ IF. I know I need two frequencies to view the curve in XY mode. Anyone know what the signals are:
Do I modulate the 10.7MHz IF or sweep it?
Where does the second signal go for XY?
Any reference or help would be appreciated.
73's
AG5EV

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