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interesting receiver chip

Vojtech Bubnik
 

especially for Steve: did you see the following single chip receiver solution?
It seemingly could decode both CW and SSB.

73, Vojtech OK1IAK

Steven Weber
 

I saw that pop up on my FB feed but didn’t investigate it. I should now.

Steve KD1JV

 

 

especially for Steve: did you see the following single chip receiver solution?

It seemingly could decode both CW and SSB.

 

73, Vojtech OK1IAK

 

 

Vojtech Bubnik
 

https://www.silabs.com/documents/public/data-sheets/Si4730-31-34-35-D60.pdf
page 15
Sensitivity when (S+N)/N = 26 dB: typical 25µV EMF
whatever it means

I am not sure what these numbers mean. Those 25uV at SNR 26dB correspond to 2.5uV at SNR 6dB, but this SNR applies to a wideband AM. Maybe the numbers will look better for a narrow band SSB or CW filter.

https://en.wikipedia.org/wiki/S_meter
S8 25.1uV RMS
S5 3.2uV
S4 1.6uV

Steven Weber
 

As a broadcast receiver, it doesn’t need to be very sensitive.

Mouser doesn’t stock the Si4735. Bummer. The only Si Rx chip Mouser has in stock is the Si4840, which only does the FM and AM broadcast band, uses analog tuning and costs US13.00 in singles. The Si4844 does SWBC in 5 kHz steps, but is non-stocked.

 

https://www.silabs.com/documents/public/data-sheets/Si4730-31-34-35-D60.pdf
page 15
Sensitivity when (S+N)/N = 26 dB: typical 25µV EMF
whatever it means

I am not sure what these numbers mean. Those 25uV at SNR 26dB correspond to 2.5uV at SNR 6dB, but this SNR applies to a wideband AM. Maybe the numbers will look better for a narrow band SSB or CW filter.

https://en.wikipedia.org/wiki/S_meter
S8 25.1uV RMS
S5 3.2uV
S4 1.6uV

 

Vojtech Bubnik
 

n2msqrp
 

This chip is used in this radio:


For a small $90 dollar radio it does a good job. I have two of them and I can pick up the local 40 meter day nets, such as ECARS, with a 6 foot piece of wire.

Mike N2MS


On March 4, 2020 at 9:11 AM Steven Weber <steve.kd1jv@...> wrote:

As a broadcast receiver, it doesn’t need to be very sensitive.

Mouser doesn’t stock the Si4735. Bummer. The only Si Rx chip Mouser has in stock is the Si4840, which only does the FM and AM broadcast band, uses analog tuning and costs US13.00 in singles. The Si4844 does SWBC in 5 kHz steps, but is non-stocked.

 

https://www.silabs.com/documents/public/data-sheets/Si4730-31-34-35-D60.pdf
page 15
Sensitivity when (S+N)/N = 26 dB: typical 25µV EMF
whatever it means

I am not sure what these numbers mean. Those 25uV at SNR 26dB correspond to 2.5uV at SNR 6dB, but this SNR applies to a wideband AM. Maybe the numbers will look better for a narrow band SSB or CW filter.

https://en.wikipedia.org/wiki/S_meter
S8 25.1uV RMS
S5 3.2uV
S4 1.6uV

 

 


 

Vojtech Bubnik
 

 

I have the CountyComm radio also and use it every morning, it is a great receiver. I hear the Tucson PL-660 uses that chip also and is another great radio.

Joel 
N6ALT

On Mar 4, 2020, at 8:25 AM, n2msqrp <mstangelo@...> wrote:


This chip is used in this radio:


For a small $90 dollar radio it does a good job. I have two of them and I can pick up the local 40 meter day nets, such as ECARS, with a 6 foot piece of wire.

Mike N2MS


On March 4, 2020 at 9:11 AM Steven Weber <steve.kd1jv@...> wrote:

As a broadcast receiver, it doesn’t need to be very sensitive.

Mouser doesn’t stock the Si4735. Bummer. The only Si Rx chip Mouser has in stock is the Si4840, which only does the FM and AM broadcast band, uses analog tuning and costs US13.00 in singles. The Si4844 does SWBC in 5 kHz steps, but is non-stocked.

 

https://www.silabs.com/documents/public/data-sheets/Si4730-31-34-35-D60.pdf
page 15
Sensitivity when (S+N)/N = 26 dB: typical 25µV EMF
whatever it means

I am not sure what these numbers mean. Those 25uV at SNR 26dB correspond to 2.5uV at SNR 6dB, but this SNR applies to a wideband AM. Maybe the numbers will look better for a narrow band SSB or CW filter.

https://en.wikipedia.org/wiki/S_meter
S8 25.1uV RMS
S5 3.2uV
S4 1.6uV

 

 


 

Vojtech Bubnik
 

bleepingbeep
 

Haha--I know you meant "Tecsun", Joel. Gave me pause, though.

Jerry AA6KI
Tucson

Vojtech Bubnik
 

https://www.dropbox.com/sh/xzofrl8rfaaqh59/AADzNmy03ChAllQ_cA0sq_Qpa/si4735_SSB_NBFM_programming_guide_20120831.pdf?dl=0

SSB audio bandwidth 1.2kHz, 2.2kHz, 3kHz, 4kHz
CW audio bandwith: 500Hz, 1kHz

various AGC configurations
tuning step 1kHz (likely this is the PLL tuning step) + digital BFO (from -16383Hz to +16373Hz)

This looks like some HAM employee of SiLabs wrote it for himself.

Ziggy
 

Arrow apparently has 13 in stock at the moment, for $10.17 each. And in SSOP not QFN :)

Also, the Si4734 looks to be the same, but without RDS support. No idea if the 'SSB Patch' is available for that device or if you could use the same one.

Cheers!

K9MR

Mike Olbrisch
 

I have a County-Comm GP5-SSB.  It works pretty well, I like it overall.  That radio is also available as the TECSUN PL360, for under $50.  I met a guy while JEEPing in WY who had the TECSUN, we couldn’t tell any difference between mine and his.  I keep mine in my bug-out survival backpack (that stays in the JEEP), and it gets used regularly on our overnight and multi-day JEEP expeditions.  It is amazing what sort of AM-BCB-DX you can hear using that little loop-stick antenna, and it is quite directional too.  Having the antenna turned the right way can be the difference between clear copy and poor copy.  Even deep in the valleys of Colorado, I was able to hear local AM (good for getting the local flavor of the area), then grab DFW on 820AM and 1080AM, or just tune around to see what you can hear.  And I sometimes monitor my friends on 80m-SSB using only the attached whip antenna after dark.  But it really works best if you string out the supplied wire antenna.  The only inconvenience is that the supplied wire antenna is not on a reel.  I can’t remember changing the batteries yet (Ultimate Lithium AA-cells), and I know some nights I’ve fallen asleep with the radio still on at low volume all night.  I keep it all including spare batteries in a little wallet-like zipper-pouch.

I have often wondered how the GP5-SSB would compare to the C. Crane Sky-Wave-SSB.  Maybe someday I’ll buy the Sky-Wave-SSB and compare them.  Or maybe someone has already done that?  Anyone???

 

When we build out our new Expedition trailer later this year, it will have 12v deep-cycle power, solar charging, and likely a Sirius-XM satellite radio as we expect to travel places where cell phones, regular radio and TV will not be available.   And I have a Shakespeare 120-55 antenna with enough elements to make it a 44ft vertical.  I’ll find a way to hang that on the trailer, and with some sort of HF radio with general-coverage RX and a tuner, we’ll be set.  Our present little expedition trailer (home-built) has no place for any antennas at all.

 

https://s3.amazonaws.com/files.qrz.com/c/kd5kc/_09_03_Elephant_Butte_Lake_SP_2_.JPG

https://offgridtrailers.com/expedition-trailer/

http://shakespeare-ce.com/military/product/120-55-at-1011u-antenna/

 

 

Vy73 – Mike – KD5KC

El Paso, Texas – DM61rt

 

 

 

From: kd1jvdesigns@groups.io <kd1jvdesigns@groups.io> On Behalf Of n2msqrp
Sent: Wednesday, March 4, 2020 9:26 AM
To: kd1jvdesigns@groups.io; Steven Weber <steve.kd1jv@...>
Subject: Re: [kd1jvdesigns] interesting receiver chip

 

This chip is used in this radio:

 

 

For a small $90 dollar radio it does a good job. I have two of them and I can pick up the local 40 meter day nets, such as ECARS, with a 6 foot piece of wire.

 

Mike N2MS

 

 

On March 4, 2020 at 9:11 AM Steven Weber <steve.kd1jv@...> wrote:

As a broadcast receiver, it doesn’t need to be very sensitive.

Mouser doesn’t stock the Si4735. Bummer. The only Si Rx chip Mouser has in stock is the Si4840, which only does the FM and AM broadcast band, uses analog tuning and costs US13.00 in singles. The Si4844 does SWBC in 5 kHz steps, but is non-stocked.

 

https://www.silabs.com/documents/public/data-sheets/Si4730-31-34-35-D60.pdf
page 15
Sensitivity when (S+N)/N = 26 dB: typical 25µV EMF
whatever it means

I am not sure what these numbers mean. Those 25uV at SNR 26dB correspond to 2.5uV at SNR 6dB, but this SNR applies to a wideband AM. Maybe the numbers will look better for a narrow band SSB or CW filter.

https://en.wikipedia.org/wiki/S_meter
S8 25.1uV RMS
S5 3.2uV
S4 1.6uV

 

 


 

Vojtech Bubnik
 

Another prototype

https://www.youtube.com/watch?v=Q50NToLuLK4

I have no idea about the noise of the VFO integrated in this DSP receiver. However, if one takes the ubiquitous
https://www.silabs.com/documents/public/data-sheets/Si5351-B.pdf
and configures it to produce 32,768kHz as a clock source for the radio DSP and one configures the 2nd clock to produce CW transmit carrier, one has a new ATS series transceiver.

Vojtech Bubnik
 

The CW/SSB patch applies to SI4735-D60 only.

n2msqrp
 

I looked at the TECSUN PL360 online and it does not have the USB/LSB BFO moes that the GP5-SSB radio has.

Does your radio have the SSB mode?

Mike N2MS

On March 4, 2020 at 12:32 PM Mike Olbrisch <mike-2020@...> wrote:

I have a County-Comm GP5-SSB.  It works pretty well, I like it overall.  That radio is also available as the TECSUN PL360, for under $50.  I met a guy while JEEPing in WY who had the TECSUN, we couldn’t tell any difference between mine and his. 

 

Hi Mike,

Yes mine Is the GP5-SSB and has no woes at all, it works perfectly on SSB every morning while listening to a 80 meter net. Battery life is great as well, I get about 4-5 months out of a set of AA Duracell’s.

Joel 
N6ALT

On Mar 4, 2020, at 10:14 AM, n2msqrp <mstangelo@...> wrote:


I looked at the TECSUN PL360 online and it does not have the USB/LSB BFO moes that the GP5-SSB radio has.

Does your radio have the SSB mode?

Mike N2MS
On March 4, 2020 at 12:32 PM Mike Olbrisch <mike-2020@...> wrote:

I have a County-Comm GP5-SSB.  It works pretty well, I like it overall.  That radio is also available as the TECSUN PL360, for under $50.  I met a guy while JEEPing in WY who had the TECSUN, we couldn’t tell any difference between mine and his. 

 

DigiKey has the chips in stock, but at a price of $18...
Your mileage may vary,
Jim W0CHL

Vojtech Bubnik
 

I ordered 5 pieces from our Aliexpress friends, I am looking forward to try it and do some receiver measurements (VFO noise, sensitivity, IMD).

It looks like this is the only part by SiLabs, that offers SSB reception, though through a unofficially leaked patch likely developed initially for US government services via CountryComm for their GP-5/SSB. I bet other SiLabs parts could do CW/SSB as well, but there is likely not enough motivation for them to develop the firmware.

This is likely the most informative writeup if someone wants to start experimenting with chip samples and Arduino.
https://hackaday.io/project/170145-si4735-ssb-receiver-controlled-by-arduino

There are some pieces around in western shops.
https://octopart.com/si4735-d60-gu-silicon+labs-19668713

Looks like the Chinese cloned this chip http://nice.kaze.com/BK1086-88.pdf
and the cloned chip is used in Digitech AR 1780.
https://forums.radioreference.com/threads/digitech-ar-1780.355785/

 

Okay, I just couldn't help myself, i also ordered some of these chips, I'm a sucker for these little projects. To me it's more fun to get a little receiver going sprawled all over my bench than to tune a factory radio.

Joel
N6ALT