SSB firmware patch for SI4735

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SSB firmware patch for SI4735

Post by Tarmo,OH6ECF » Wed Apr 29, 2015 5:19 am


Sparkfun is selling SI4735 AM/FM tuner chip. I kindly ask you to to offer those chips with "SSB firmware". Silicon Labs have confirmed, it is available, and this chip seems to work well as SSB receiver, on its own class. (Example: ... -portable/ )

I also would like to see this "SSB-chip" also on shield and breakoutboard.

This chip have great advantages: It has automatic (and manual!) antenna tuning capasitor, several channel filters, low (real low!) power consumption, s/n meter, kind of squelch, and a lot more, it is awesome for radio amateurs and other persons active on radio.

I have been using discontinued SI4735 tuner shield, and is its surprising receiver. It can be tuned up to 10 meter amateur band (over 28 Mhz) and it can be used for SSB-receiving with external local oscillator. I have received SSB-speech,weatherfax images, Thor-transmissions and CW with it. Image supression is a problem with this kind of setup. But with SSB-firmware it could be a good SSB-receiver.

RasPi can be used as a barebone RF-transmitter. With this chip it could be used as a ham-transceiver. With Arduino style boards, AD9850 DDS-board (cost around 10 dollars) can be used for transmitting and with SI4735 "SSB-chip" it makes real ham-transceiver.

I guess Sparkfun only have to order these chips with please please... :D

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Re: SSB firmware patch for SI4735

Post by TS-Liz » Mon May 04, 2015 11:50 am

Hi! Thanks for the suggestion! I'll pass it along to our Catalog team.
Happy hacking!

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Re: SSB firmware patch for SI4735

Post by Tarmo,OH6ECF » Tue May 05, 2015 12:26 am

Thank you very much :dance: I hope I can change updated chip to shield some day (or have updated shield).

Example of using SI4735 as "bandscope", utilizing RSSI and S/N -meter of chip, here (on currently unfinished page only, sorry):

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Joined: Fri Dec 11, 2015 1:33 pm

Re: SSB firmware patch for SI4735

Post by jor » Tue Dec 15, 2015 5:39 am

Hello Sparkfun,
I agree with Tarmo OH6ECF thad the Silicon labs Si4735 receiver chip with the SSB demodulation option is the way to go.
If SSB is possible there will be a large market for new designs with this nice chip.
We "Multi Tech Support/ KTH rf-Design" have designed some test PCB's for the Si4835 chip without microcontroller and prohibit the micro controller's noise and it work well. ... -receiver/

If the Si4735 SSB option come available it is possible to design modules for receivers and transceivers .
Please ask Silicon Labs to release this SSB chip or program option, thad is where we are waiting for.

Best regards Joris, KTH rf-Design Ham call PE1KTH
The Netherlands.

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