Re: Ideas for AM, NB FM Demod and CW filter board


Nelson
 

Although having the ability to xmit AM etc would be nice, perhaps foregoing xmitting and including a simple AM detector circuit so the receive section could also be a general coverage SW receiver.  It seems it would be easy to do a mod for reception, especially since I had to add a high pass filter to keep local AM stations from swamping the bands.  I could get excellent reception of one local AM BC Band station without any alteration to the circuit so it was getting into the audio amp section and getting rectified somewhere...

Nelson, KG7GYS

On Tue, May 29, 2018 at 9:35 AM, Rahul Srivastava via Groups.Io <vu3wjm@...> wrote:
Hi!

I was discussing with Farhan on this topic for an add on demod board to add more versatility to uBitx.  CB radios often used a common chip for AM as well as NBFM receive. I enquired here and TDA1220 is available in mkt for slightly more than a $.

With the parallel XF mod maybe we can have an add on board with this chip and a 6 pole Cohn CW xtal filter. 2nd IF's now being 12MHz SSB, 10.7MHz + 455KHz for AM/FM and possibly 8.xx MHz or some other for CW. 

Guys what to suggest..

73

Rahul VU3WJM 




--
I always thought the Universe was a wonderfully strange place until I studied Particle Physics - I now know the Universe is, in fact, profoundly odd in nature

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