KitsAndParts.Com Forum

W8DIZ · 2008-08-12 14:27:26

Build this Universal Gilbert Cell Audio Detector for $9.
Crystal supplied for 5.068 IF (BFO)

http://kitsandparts.com/612mixerb.ph

-Diz, W8DIZ

ki4mmm · 2009-03-28 12:13:30

I've looked at the data sheets for the SA612/602, and Googled for every combination of descriptive words I can think of, but I can't find any information on how to feed the 612 with an external BFO. Everything shows oscillators, with crystals and caps between pins 6 and 7. Presuming a BFO would feed in on pin 7, I don't know what to do with pin 6, etc. I could use Tom's idea of just using the onboard crystal (great idea!), but it would be nice to use the Universal BFO output. I'm thinking I need one cap between pins 6 & 7, and one between pin 6 and ground. I found one reference that gave a formula for those caps (f/100 and f/1000), but for the example that went with it, the math didn't work out.

Any ideas, anyone?

Greg
ki4mmm

W8DIZ · 2009-03-28 13:00:36

ki4mmm wrote:
I've looked at the data sheets for the SA612/602, and Googled for every combination of descriptive words I can think of, but I can't find any information on how to feed the 612 with an external BFO.
Greg
ki4mmm

Hi Greg,
This quote is from the SA612A spec sheet: http://rfkits.com/parts/SA612A.pdf
"If the required L.O. is beyond oscillation limits, or the system calls for an external L.O., the external signal can be injected at Pin 6 through a DC blocking capacitor. External L.O. should be 200mVP-P minimum to 300mVP-P"
73, Diz, W8DZ

ki4mmm · 2009-03-28 20:00:56

Thanks Diz! I guess it is obvious that I just looked at the pictures :-).

Greg
ki4mmm

KitsAndParts.Com Forum

#1 2008-08-12 14:27:26

Audio Detector - Gilbert Cell using SA612AN

#2 2009-03-28 12:13:30

Re: Audio Detector - Gilbert Cell using SA612AN

#3 2009-03-28 13:00:36

Re: Audio Detector - Gilbert Cell using SA612AN

ki4mmm wrote:

#4 2009-03-28 20:00:56

Re: Audio Detector - Gilbert Cell using SA612AN

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