Saturday, February 27, 2010

2-meter FM receiver with MC3362 chip and Si570 synthesizer


I discussed the Si570 and controlling it with my Arduino in an earlier post.  The fact that it can reach 160 MHz made me think of using it for 2 meters (146 MHz).  I tried to homebrew a 2-meter FM rig back around 1979 / 1980 with limited success and always wanted to give it another shot.  Plus, I've seen many articles about using the various integrated radio chips for ham use and was intrigued.  Most of the articles diverted the VHF / FM chips for usage on HF receiving CW and/or SSB.  That sounds great, but I wanted to try one in its "native" mode first.

The MC3362 isn't a car radio chip, as I'd thought at first.  It was intended for 49.7 MHz FM (was that toy walkie-talkies?  Or cordless phones?) and ~160 MHz weather receivers and even for ham radio.

Rather than describe all the details here, I'll link to my web page, which seems better suited for such things -


And I want to include the link to my schematic in JPG format -


Yeah, it works.  Sounds pretty good.  Now if I could just come up with a companion transmitter, I'll have finished that 1979 project at last.

Right now I'm working on a crystal oscillator 1st LO so I can make it independent of the Si570, although limited to frequencies I have crystals for.


3 comments:

Rajesh K said...

Nick, I tried mc3362 with si5351 instead of si570. The audio is raspy and noisy. Is square wave OK for the mixer in mc3362? I read that sq wave is not good for gilbert mixer in mc3362 and low pass filtering is required to prevent harmonics. What are your thoughts on this?

Rajesh k kc2kby/vu3rgk

Rajesh K said...

Some more inputs...I built the osc with arduino in a separate box (to reuse it for antenna tuner project) and fed the mc3362 board via rg58.

Rajesh K said...

Nick are you there? :-)