I’ve received a number of inquiries from SWLing Post readers lately regarding an inexpensive Si4732-based mini stand-alone receiver being sold on Amazon and eBay for around $56-66 US shipped.
The radio is based on the Silicon Labs Si4732 DSP chip which provides the following frequency coverage:
- FM (64–108 MHz) with RDS
- AM/Mediumwave (520–1710 kHz)
- Shortwave (2.3–26.1 MHz)
- Longwave (153–279 kHz)
It appears the bandwidth selections are 0.5, 1.0, 1.2, 2.2, 3, and 4 kHz.
If 4 kHz is the widest AM bandwidth, that is a bit unfortunate. The radio does have a BFO for tuning SSB and CW signals.
If I’m being honest, even though the price is a no-brainer, I’ve been hesitant to buy it simply because, due to my limited free time, I really do seek enthusiast-grade receivers for review these days. I’m less interested in radios that are cheaply made and lack the sensitivity, selectivity, noise floor, and features an SWL would desire. In other words, I’m a bit skeptical this receiver will be a proper performer.
The frequency range is certainly adequate and Silicon Labs chips are a quality product, but as we know the Si4732 is only as good as its implementation (click here to read the PDF data sheet).
I’m curious if any SWLing Post readers can comment with their experience using one of these Si4732-based receivers. Did it live up to your expectations? How does it compare with, say, an XHDATA D-808 or Tecsun PL-330? Is it sensitive with the supplied whip antenna? Does it have many birdies or other internally-generated noises? Please comment and let me know if this radio is worth checking out!
Click here to search eBay for this radio.
Click here to check it out on Amazon.com. (SWLing Post affiliate link)
It is now cheap between $35 and $20
I grabbed the Plus version (ATS-20+) from AliExpress for £24 delivered to the UK last week and have had loads of fun with it so far.
Being a seasoned electronics engineer and incessant tinkerer, I’m now setting about modding it so started with a firmware upgrade to PU2CLR’s V3.0.7g. It’s available as an Arduino sketch so is easily customisable in Arduino IDE. So far, I’ve tweaked the band plan to be more UK-specific and tidied up the UI a little.
As another poster has already mentioned, a couple of fast signal diodes in inverse parallel across the antenna input is a sensible precaution due to the Si4732 IC its based on being fully CMOS and easily “zappable”. I’ve gone for a pair of cheap BAT41 Schottky barrier diodes.
I’ve also replaced the original 1Ah LiPo with an EEMB LP605575 2.75Ah LiPo to give around 48 hours runtime per full charge. It fits perfectly without touching anything it shouldn’t on the underside of the PCB if mounted tight into the front left corner of the lower case. The connector type and polarity are the same, so it’s a straight drop-in replacement.
NOTE: This larger LiPo likely won’t fit in the non-Plus version due to components mounted on the underside of the PCB that may foul on it.
Interference rejection is poor as is common with most budget receivers, so I have a tuned SW “donut” antenna with high input impedance RF buffer amplifier on the way to improve selectivity. I’ll also be chucking together an adjustable gain wideband RF amplifier to go between this and the receiver soon.
If you’re looking for a SW receiver that works great out-of-the-box, an ATS-20/ATS-20+ is probably not for you, but if you’re a radio enthusiast on a budget with a basic understanding of antenna theory who enjoys diving in with firmware/hardware modding, it’s an excellent budget starting point for sure.
I received mine about 2 weeks ago from ebay. I upgraded the software to version 3.08. I also wired 2 1N4148 diodes back to back onto the antenna jack. This helps reduce any surges from the antenna. I have zapped other products like this in the past by not installing protection diodes. Performance wise it is not bad, although it picks up all the noisy laptops inside the house. On shortwave ham bands, this set works fairly well on SSB. A nice toy for the money.
I used 1uH or less for short wave; higher value (do not recall) for Medium wave.
WITH added Switchable front end inductors this is on a par with the iconic Belka DX; without said inductors all you hear is mush.
The Si4732 has an auto-tune ability with these inductors, explaining the very good performance.
Do you have the suggested values for the inductors for different bands? I see nothing in the Silicon Labs documentation (including AN-233) about this – they only detail what to do for AM and FM bands.
Regarding a lot of people’s comments, this radio is highly hackable, since with PU2CLR’s library and sample code that is found in the ATS-20, you get access to every function the chip has, once you download the Si473X datasheet and App Notes 233 and 383. The former gives all of the commands you can send to the chip over I2C, the latter gives a lot of information about how to connect antennas to it properly. And of course, Ricardo’s (PU2CLR) documentation on Github is excellent. The ATS-20 itself does nothing to help with this, except that it connects the RF inputs directly to the rear-panel BNC jack, which means you can implement any of the recommendations in the datasheet or app notes using external circuitry, without internal components interfering. This typically involves nothing more than adding an inductor and capacitor or two, but they also suggest an AM trap for SW reception. Which means you can make separate plug-ins for each band you’re interested in, and optimize them for your needs. In my experience, there is more of a problem with FM stations splattering all over the SW bands, but a 100 MHz trap should eliminate that.
Hi David,
Not sure you’ll see this but worth a shot! For SW reception did you just add a 1 uH fixed inductor between the RF input and the chip? Thanks!
Sam WN5C
I just picked up the ATS-20+. What can you do with the “USB Download” port on the back of the receiver?
Got ATS-20 with V1.1.5 software. WITH added aerial coils (fixed small inductors) for MW and SW the chip is self-tuned and has excellent performance especially with an outdoor aerial.
Mine is great I have picked up an FM station that I cant get on a few of my other radios. AM is Decent shortwave is ok. I have really enjoed mine. Only complaint each time you turn it off it resets to FM. I would buy it again.
Remark: ubuntu 22.04 has a problem on ttyusb …
See
https://askubuntu.com/questions/1403705/dev-ttyusb0-not-present-in-ubuntu-22-04
Now I can program again!
Now, on Arduino 183, my tools–> ports is always grey. Can not select any port.
What is wrong? Linux, Ubuntu 22.04.1 LTS
I uploaded software to the ats20 before … (last year or so)
Just got this radio???
What a piece of CRAP!!
I can’t even receive a local am station !!
Nothing works.I am a 50 plus General ham. It is connected to a 50ft long wire antenna.DON’T BUY THIS !!! 73
Yeah, it’s garbage, at best. The one I have hasn’t worked like it’s supposed to, even after the software upgrade. It’s supposed to receive the HF bands from 160m to 10m (it can barely receive WWV’s signals), and the full commercial AM and FM broadcast frequencies, but, without low-pass or high-pass filters (way too much interference from the local AM and FM stations), it’s next to useless.
Don’t waste your money on a cheap receiver. Spend a little more, and get a real communications receiver from Icom, Kenwood, Yaesu, or any of the other real radio manufacturers.
I bought one. It was great! My brother liked it and I gave it to him for his birthday; So I ordered another and this one is junk-noisy, and not sensitive at all! Ali Baba is a scam site I think. Getting to someone to try to get it replaced has not paid off. So I took it apart and I’m not sure it’s a “real” ATS-20. It sure doesn’t seem to fit the descriptions I’ve read here. Would someone upload a photo of the board so I can compare it to mine.
BTW, I love this site. I’ve done a lot of reading on it but this is the first time I’ve commented.
I’d like some tech comment on whether this Rx can Rx NBFM acceptably below the Nz and AUST commercial FM band , starting 98 Mhz DOWN . NB narrow band which is what the country police and fire services in Nz use. Some one asked me about scanner prices and they are shocking so I was wondering if this ATS might fit the bill.
I am guessing the answer is YES but with a software Kludge – but how messy is it ? any experience ?
Hi
Just bought the ATS -20 Radio and I’m wondering if anyone can give me instructions on how to use any or all the Functions on the Radio.
Also all advice on Antennas to use would be greatly appreciated
Kind Regards
Pete
mine is locked up..turns on and thats it. no sound no button function no knob function. Im not a programmer and know nothing about ardrino..or how ever you spell it. glad it was only 50 bucks
Can anyone advise if this Rx either as is or with a modified firmware build Rx NBFM between its low limit of 64 Mhz and 80 Mhz. There is a lot of interesting stuff in here in Nz – taxis, Country police and repeaters (not big city police who are on Trunking radio ..) .. .etch etc.
I know an unmodified DEgen 1103 will rx NBFM on the bottom end of its Rx band because it covers below the conventional Aust and Nz commercial FM band (to cover the Japanese situation). I can’t assume to translate from that Degen radio to the newer ATS-20.
Any experiments, insights, Software Github directions, Opportunities to Beam up with Scotty to the USS Enterprise ?? I am all ears. TIm Fidler NzL
The RX radio on a chip will not allow it to go down onto those frequencies as well as it does not have NBFM support onboard. I’ve been trying to hack them out of bands for a while and it just will not do anything outside the FM bcast band. It can be kludged out of band on HF and down, but FM was just a quick and easy selling point.
Mine did something similar but it straightened itself out after multiple attempts at starting it up. If you are any good with a soldering iron I would open the case and look for cold soldering joints. I’ve heard they can be a problem with some of these units.
mine did to but i charged it up then turn it on and off a few times it started to work then
Need a source for a charger ( oilder type plug) for my Si4732 radio. Did not come with one, Help !!!
Look on Amazon, their fairly inexpensive.
My radio came with a so called Mini-USB port. But I have seen with Micro-USB port as well. The radio charges from a USB-charger’s or a computer’s USB-A port with a USB-A to USB-Mini or USB-Micro cable. The same cable can be used to program the radio. Plenty of USB-Mini pictures on the Internet to see if your radio has a USB-Mini or USB-Micro connector.
So I wanted to figure out if I could adapt the sketches…
ATS 20 SI 4732 radio programming with Raspberry Pi running Ubuntu Mate 20.10
Make the user member of the group dialout to be able to use the serial port for uploading
Administration
Users and Groups
Manage Groups
Select dialout
Mark the User to become a group member
OK
Close Manage Groups
Connect the radio to an USB 2.0 port
Reboot the Pi to activate the user’s dialout membership
Switch on the radio to activate the radio’s serial port
Get the SI4735 repository with specific programs for this radio and other projects
Use a terminal command to clone the repository
>git clone https://github.com/pu2clr/SI4735
Install Arduino IDE manage the built in Arduino
Download Arduino IDE voor Linux ARM 64 bits
https://downloads.arduino.cc/arduino-1.8.13-linuxaarch64.tar.xz
Use file manager to extract the files from the container to your home directory
Use file manager to go to the new directory
Use file manager and right click to open install.sh
Set up the Arduino IDE to program the radio
Use file manager to go to: ~/SI4375/examples/SI47XX)KITS/AliExpress/SI473X_ALL_IN_ONE_OLED_RDS_CHINESE
Use file manager and right click to open with Arduiono IDE
SI473X_ALL_IN_ONE_OLED_RDS_CHINESE.INO
The Arduino IDE opens and then do the following
Tools
Manage Libraries: Install SI4735 library, install Tiny4kOLED library
Set Board to “Arduino Nano” (that’s what was printed on my Arduino)
Set Processor to “ATmega328P (Old Bootloader)”
ATmega328 wat was printed on the chip of the Arduino
Old Bootloader was recommended after an error messages)
Set Port to “/dev/ttyUSB0”
Finally upload the sketch with the IDE
Sketch
Upload
Now I can.
Hi, I end when I need the lib Tiny4kOLED. It is nowhere in the libs list. And can I try this on a box that is not an ATS20, but another, same design box?
You can install the Tiny4k)LED library through the Arduino IDE:
-Tools
-Manage Libraries
-Type: Tiny4koled
-And then click install
You can update the repository in the Pi’s terminal:
cd
cd 4735
git pull https://github.com/pu2clr/SI4735
Today I found version 5. Works great!
Whether it works on every AliExpress ATS-20 radio I can’t tell. YMMV.
I basically as you outlined and updated fine. Thanks
Frankly, I’m impressed with how well it receives. Here’s a huge downside however and I’m wondering if I got a faulty radio. The radio does not remember the frequency, mode, etc. when you turn it off. In other words it always defaults to the FM band with a rather loud volume on every power up. You have to scramble to turn it down and then work your way to whatever band you want to listed to. I wonder if there is a fix for this?
With version 3.0.7a from github, after 10 seconds of not changing any setting, the current settings will be saved in EEPROM. The radio waits 10 seconds to write in order not to wear out the EEPROM too soon. By pushing and holding the selector during start up, the EEPROM will be cleared. The latter may come in handy after a version upgrade.
I have one on the way. Will report.
Just update, it’s simple, the current version is 3.x.x
I got the SI4732 yesterday and reviewed shortly here:
https://swli-05940-mi.blogspot.com/2021/04/si4732-shortwave-receiver.html
73, Oscar
Love mine…so much so I’ve ordered a second. I think it outperforms the Tecsun PL-880 on MW. Most certainly outperforms in Sangean ATS-909x.
Seriously? so the research and development work of the team of engineers from Sangean and Tecsun to develop the ATS-909x and PL-880 was worth nothing, since they are worse than a receiver made in the house garage by laymen without any technical criteria, without BPF/LPF filters on the frontend, unstable software, etc. LOL
Well … The box is better than my tecsun pl390, because of the ferrite in that 390 … I have a Sangean PRD4W, with FM filters, and I’m waiting for the implementation of these fm filters in the box, so that an external antenna ..
Hi Dr, Elman, Great comment here. I have been a SWL since the 60’s, and a ham since 1969. I have a Tecsun PL880, and mostly love it’s performance and FULL SOUND. I am listening to an ATS-20 on 7.188MHZ LSB to the Hole In The Wall net, pretty loud on a 60 ft high 40m Cage Dipole here in GA. I have heard Australia and South Africa recently. Right now it is jumping a step or so on the BFO, and the poor SSB overload on every syllable beginning AND synthesizer chuffing/muting with every detent of the dial is the BIGGEST shortcoming.is annoying just like my PL-880. The AGC on/off and ATT steps do little to help on my ATS-20. Can’t find ANY schematic and the Skyworks Radio chip datasheet (publicly available) is only 3 pages long! Somewhat worse on my PL-880 is some gain ranging which the Signal Strength meter reflects, on low or no signal is very tiring. The 880 sounds better on it’s bassy speaker, than my Dell monitor sound bar, BUT the ATS sounds mellower on those PC speakers. My Novice receiver was and still have Hammarlund HQ129X with great sound and selectivity. Also TOTALLY restoring and upgrading my WW2 Hallicrafters SX-28A. My daily Ham band listener is a restored 1970’s Kenwood R599, with added PS filtering and every audio coupling cap 2-10X in value, feeding a B&O S45 Phase Link speaker. It has 3 Amazing 8 pole Crystal Filters in it, and a VFO that spins 600KHz at one spin! I should have bought the ATS-25, much more featured Display and more, but if still unstable freq and overload is not any better from comments I read. TNX W4HDL
The success of this radio and the high performance achieved with the Si473x IC is not due to the Github library or the arduino code used, but rather the team of programmers, engineers and developers from Silicon Labs who did a beautiful and arduous work in the creation of this integrated circuit and the SSB Patch. Any radio that is assembled using the Si473x will work just fine. Many want fame by taking advantage of this. Congratulations to Silicon Labs!
No text about the SI473X device family I have read contradicts what you have just written. I agree. The SI473X is a great device with excellent performance. It doesn’t take much to develop a good receiver with the SI473X.
For $50 bucks and little more, I buy the Tecsun PL-330 without thinking twice. With SSB and the new ETM+ function it is unbeatable.
Absolutely in agreement. Prior to purchasing my PL-330 I had a PL-660 which is, by all reports, supposed to be excellent. However, I could barely pick up any amateur SSB. In a couple weeks of owning the 330, I’ve listened to 10x more SSB than in 2 years of owning the PL-660. Based on the great reviews, I must have had a bad sample.
Dear Sir,
Can you tell me SI4732 needs what type of charging cable to charge the 3.7 volt battery. Thank you
Look at the charging port on the back of the radio. They had 2 versions, mini USB or micro USB. Just get the USB cable for ur version and any cell phone 5 volt charger works.
Hello. I’m the developer of the Arduino Library that this receiver is based on.
The Library I have developed has more than 30 examples showing how to use it with many displays and other devices. These examples were made to guide the users, hobbyists and experimenters to build your own receiver by using Arduino platform. They are not intended to be a final product. It seems this receiver used one of these examples with few modifications or no modification. I’m not sure about that. All example code that use SSB patch have the following advice:
It is important to say that the SSB patch content is not part of this library. Also it is important to say that the author of this library does not encourage anyone to use the SSB patches content for commercial purposes. In other words, this library only supports SSB patches, the patches themselves are not part of this library.
To implement the patch functions in the library I used the guide SI47XX PROGRAMMING GUIDE AN332; page 236 (Item: 7.2. Powerup from a Component Patch);
Also, on Silcon Labs website, support and community, there is a topic called “SSB and/or ASK/FSK/nPSK demodulation on Si radio chips”. If you follow that topic, you will see a post from a member called “DASM” making available a SSB patch for the Si4735.
Finally, this library was built based on “AN332 Si47XX PROGRAMMING GUIDE REV 1.2” and AN332 REV 0.8 UNIVERSAL PROGRAMMING GUIDE AMENDMENT FOR SI4735-D60/SI4732-A10 SSB AND NBFM PATCHES. Both documentation is available on the internet.
More about the Library I have developed on https://pu2clr.github.io/SI4735/
how or where do i connect a small loop antenna too it?
Thanks!
Instability? I see that connecting/changing antennas can make the receiver “hang”. The display freezes, most of the buttons no longer work. Probably a too heavy load …
There is an update with the addition of 5 capasitors that will stabilize it and it will stop that.
Do you have a link to that mod? Tanks in advance.
The SI4735-D60 SSB Patch code was “stolen” from SiLabs since it is company confidential and there was no formal authorization from Silabs for third parties to market it and make profit from it. Sad story.
I have 2 of these. The encoder failed on the first within a week. The radio is based around an Arduino nano or a clone of one anyway so firmware can be flashed. Out of the box both of my sets covered 160 metres. Reception on the telescopic whip isn’t bad and I have not found the receiver particularly noisy. Quality is however pretty poor, the soldering inside is not good and I suspect many components are not up to the job- for example the encoder and the power switch. I would not really recommend this radio unless you want to play around and work on it. It’s not a finished product although it does have potential in its current form it’s rather a poor implementation.
I eagerly awaited the arrival of 2 of these radios, and I had high hopes for their performance. However, now that I been working with them for a few days I am quite disappointed. Here’s why.
1. The rf input section is very basic and does not follow the recommendations of Silicon Labs AN383 Antenna Design Guide. The rf input section consists of a bnc connector, SPDT selector switch for the AM and FM inputs on the chip, and a single series capacitor in each of the chip’s rf input lines.
2. The rf input has no ESD protection. One static discharge to the included rod antenna may kill the SI473X. Outdoor antennas may make this problem worse.
3. The I2C bus operates at 5V which is not suitable for the 3.3V rating of the SI473X. Level tranlators are omitted from the design. The long term result may be damage or erratic operation.
4. The rf sections aren’t shielded, so the radio is noisy.
5. The front panel is a circuit board on which the push button switches and the rotary encoder are mounted. They are mounted on the rear of the board and protrude through holes to the front of the radio. The switches and encoder are only held in place by their leads which are soldered to the rear of the panel circuit board. Each time a button is pressed the force on the leads pulls away from the board.
Over time, it is possible the traces will separate from the board.
6. The rotary tuning encoder operates erratically. Sometimes the frequency doesn’t change for every click. Sometimes it takes 3 or 4 clicks for the frequency to change. Other have reported this issue.
7. I am sure there is more.
This radio reminds me of my old Realistic DX-394. Modifications may improve hardware shortcomings, but they never fully correct hardware design flaws. With just a bit more work by the designer, this could have been a cool little radio, but I find it to be quite a disappointment. That’s too bad, because the library and sketches developed by pu2clr are quite good and are constantly being developed and improved. Unfortunately, I don’t think this radio will be able to take advantage of improvements in the firmware/software.
Ultimately, it seems these radios represent a fast tracked design designed to earn a profit based on the hard free and open source work of others. My advise is to save your money and buy something like a Belka-DX.
About the 3rd statement, I would like to know just out of curiosity, if the circuit is powered by a battery of 3.7V, where these 5V come from?
Thanks for the tech insights.
Basic ESD protection should not be too difficult to add. A couple of diodes as a start.
I know the radio has a Si4732-A10 with lower voltage limits, but it would not surprise m0 if the bus voltage was (loosely) chosen based upon the the similar Si7435-D60 being rated for up to 5.5v supply voltage.
The Si4732-A10 is rated for up to 85C, so I suppose it might survive at higher voltages assuming the chip package does not dramatically overheat. Checked the chip temps? Maybe add a heatsink as a potential mitigation.
Still, if it it as 5+ volts, looks like it will need a different voltage regulator substituted.
i will look into better securing the controls. Probably nothing too elaborate, though, as the VFO encoder already seems suspect and probably ready for a better replacement. Hot glue anyone? 🙂
I have one of these radios on order from China. Thankfully my expectations are rather low, so I am looking at it more like a kit project. I figured it might be worthwhile to tweak and modify into maybe something actually resembling a marginally usable radio.
Just noted the bus issue versus a supply issue. The Arduino clone board probably is ~5v, which in turn powers the SiLabs chip, right? Hmmm.
You might drop the Arduino clone to 3.3-.3.7v. A “better” solution might be tapping 3.7v and use a Ti CD4050 or similar buffer between the Arduino clone and SiLabs chip.
Guys, pay attention, there is no 5V on this receiver to cause unstable operation or burn out the Si4732, this is fake news. The I2C logic levels of the arduino follow the voltage that supplies the same, which is done by a 3.7V battery. The problem occurs due to instabilities in the operating software.
It seems the software used by this receiver was gotten from an Example of the Arduino Library I have developed (PU2CLR SI4735 Arduino Library). I have not experimented instability in my prototypes.
The radio concept is great but is hobbled by shortcomings, which will hopefully be addressed by the manufacturers as sales start dropping off and complaints from users amp up. It has promise, so here’s hoping. I can quote an example of this sort of evolution: I was one of the first to buy V.1 of the HF Signals uBITX SSB transceiver board and it soon transpired that there were design issues. Notably a self destructing LM386 audio chip, problematic T/R thump, out of spec spurs on transmit and a lot of code issues. Fixes emerged for all and most of us did them. They are now on to V.5 of the radio with great design improvements in all respect. At the outset it was made clear that it is still as a hackable experimenter’s radio…but then these are radio amateurs buying who have for the most part considerable hands-on expertise and original build quality is excellent. There will be the si4732 enthusiasts who will enjoy a challenge but not so sure that the average SWL needs or wants that. 73 Paul ZS2OE
Correct. The Arduino runs at 3.3v and there are no 5v I2C lines going into he SI chip. Looks like they have cut the 5V line coming from the USB connector and fed it to the battery charger and the output of the Li-Po battery is fed to a regulator (very likely linear) to get 3.3v.
If the Nano board is connected to a USB device, like when its FW being updated, the 5 V voltage from its USB port will bring its supply voltage to 5 V. This overcomes the 3.3 V source from the LDO regulator outside of the Nano. The only thing in the way is a forward biased diode (on the Nano) so the Atmega328 power supply voltage is still at 4.4 V or thereabouts.
Thanks for reporting.
I do not have details about the design of this receiver. Judging by the photos, it seems it is similar to the prototypes I have made to check the library I have developed. My prototypes were made just to help me to develop the library (POC, tests, improvements and bug fixes) and also to guide the designers to build your own receiver. Some important aspects of a final receiver were not addressed in the prototypes. For example: front-end; LNA; Band Pass Filters; etc.
73,
PU2CLR.
Ricardo.
Judging by this video https://youtu.be/A3Mus-7lTrk the radio is a piece of garbage and the operating software is very unstable, the SSB patch belongs to SiLabs, they should take a look at this. You can’t expect much from a mass-produced integrated circuit that has been developed for popular radio. I wouldn’t buy it.
Nobody is forcing it on you. It is an experimenter platform, Not a Collins 651S1 if it were it would be $4000.00 USD not $49.95 USD!
But I’m not going to buy this garbage anyway, I’m not going to throw $ 50 in the trash can. Even more knowing that Silicon Labs software was pirated.
This radio is a commercialized manifestation of the very good development work of pu2clr. As others have said, it is not a stellar performer, and it has many shortcomings. Some of the issues are hardware related, and won’t easily be overcome.
That being said, it is an inexpensive device which lends itself to experimentation and custom configurations due to being based on the Arduino platform. Some issues will likely improve as the firmware design improves with time.
I look upon it as an interesting way to gain experience that is affordable. For serious listening, I’ll always revert to my better radios
It is important to note that the author of the Arduino library which this receiver is based does not encourage anyone to use the SSB patches content for commercial purposes. In other words, the library only supports SSB patches, the patches themselves are not part of the library.
SiLabs programmer’s guide sez 4732 supports 6 kHz BW, so should be possible with minor code modification if description is correct that it ships with 4 kHz max BW. https://www.silabs.com/documents/public/application-notes/AN332.pdf
I bought one from AliExpress. I intend to improve my sketch examples based on users comments of this receiver. Regarding the BW, all sketches I have built implement 6kHz on AM mode and 4kHz on SSB. Judging by the SSB patch guide of SIlicon Labs, 4kHz is the maximum value.
I have had the A10 drop into 6khz on ssb, but the bfo became very flakey. I think it was just a firmware bug on the chip that caused it to function at 6khz. Been working heavily on the sketch trying to find any other bugs on the chips code that could be exploited. I have come to the point of running out of storage space on the nano to continue much further without stripping out large chunks of code.
I have a feeling that these radios would have the same issue as the Malakite sets that have an impedence problem with the high impedance of the whip antennas, resulting in almost no reception of LW, MW or SW when using the whip.
This iC is used on portable radios using a whip antenna and it has high impedance input, not 50 ohms like the Malachite.
This is the worst radio I’ve ever had, the software is a mess, the display is very small, a poorly designed interface, full of digital noises. I prefer to spend on an XHDATA D-808 that besides being portable, sensitive and beautiful, everything comes complete with Air Band and quality RDS.
There is a version of this radio on Ebay (from a number of sellers) that is about half the price but you have to put it in a box and do a little soldering. If you like to solder stuff together and finish it, it is something to consider.
I prefer a nice color display with touch screen, frequency spectrum display and pull down menus.
I have a Malachite SDR receiver ordered, though it will take a month to get here from China!
https://github.com/pu2clr/SI4735 here is the repository for the library that is used to control si4732/4735
Hook it up over USB, fire up Arduino IDE, add si4735 library and load sketch from examples.
Ones that work without any modification are under SI47XX_KITS/AliExpress/
They also include patch for SSB – LSB/USB.
Note that if there are any gaps in receiving bands, those can be modified in the sketch code. I am pretty sure that i was listening 160m band on this radio.
This radio should contribute very much to tinkerers, as we may expect modifications in the future – i plan to replace Arduino based board with ESP32 based one because currently nearly all memory is used by the sketch. Also, i am working on 3d printed case.
Check out amazing work done by pu2clr and contribute if you are able :).
https://pu2clr.github.io/SI4735/
I have one on order via eBay from China.
The Si4732-A10 probably is close to the Si7435-D60, assuming it is not essentially the same architecture in a different package format with a lower voltage threshold.
So if assuming they are similar, Silicon Labs has actual Si7435 tech specs here:
https://www.silabs.com/documents/public/data-shorts/Si4734-35-short.pdf
https://www.silabs.com/documents/public/data-sheets/Si4730-31-34-35-D60.pdf
If someone wants to open there radio to confirm before mine arrives, I suspect it might have a DCCduino Nano inside. Perhaps even with a CH340/CH341, (likely counterfeit) FTDI, or similar USB comms chip; which could open up more possibilities for those wanting to experiment with the radio code.
Hi, I did a lsusb on my linux system, and it shows up as a
1a86:7523 QinHeng Electronics HL-340 USB-Serial adapter
What about that? Can I load new software on it?
Cool. Looks like it has a CH340/CH341 chip, so yeah, in theory you should be able to experiment with the software, such as flashing updated firmware. Hopefully pu2clr and other devs will have some tutorials in the near future assuming the radio proves popular.
In the meantime, you might see if a serial terminal app like Minicom can connect to it. Some ideas on possible support libraries and connection parameters here:
https://github.com/boseji/CH341-Store
https://unix.stackexchange.com/questions/189896/testing-qinheng-electronics-hl-340-usb-serial-adapter
I’ve just had an email to say that mine has shipped. I intend to use it with an indoor MLA-30 which is performing very well with my RSP1a. So, I’ll report back!
No 160m band? Oh calamity!
I have been eyeing these radios, too. I especially like the prospect of being able to update the code as new features and capabilities are developed. I joined several Facebook groups centered on these kits and have watched all the YouTube videos I can find about them. I have yet to pull the trigger and buy one, however. The price has taken a jump over the past week (no doubt the Chinese suppliers have noted the increased interest) and reports from early users indicate there are manufacturing and software issues in some of these units, so anyone who buys one at this point should expect to be a beta tester and maybe need to spend some time updating their unit to get the radio to perform. Still, they are an intriguing product and I may purchase one.
I too just ordered one to try. All the other radios I got has a bunch of static on them. What I want is shortwave that picks up good signal. And no static. One radio I got receives 3 radio stations on one frequency. How can anyone listen to that. V115 is not worth the money.
“All the other radios I got has a bunch of static on them. What I want is shortwave that picks up good signal. And no static.”
This is not going to fix that problem. Analog signals on shortwave have static by definition. Even the best reception is going to have poor audio quality and frequent noise interference when compared to digital audio or FM. If you want to get better quality reception, you need to focus on other components. Any radio with a basic antenna is likely to have poor reception, making the antenna an important part of your receiver setup. Your local environment also causes a lot of noise which antennas can’t always filter. Even if you buy the most expensive and well-regarded receiver out there, you won’t get the quality you expect unless the antenna and environment are also suitable. I suggest that you listen to some of the recordings in the shortwave radio audio archive so you can hear what qualifies as good reception. It includes quite a bit of static.
For shortwave reception the antenna and the location are very important, the receiver is not. My Yaesu FT450AT can receive the same AM broadcast stations on shortwave as my do-it-yourself one tube.
To avoid “man made noise” I go into the woods our somewhere elase “away from civilization”. The Si4732 ATS-20 is a leightweight solution. I will add a RF transformer for RRF input matching and a wire antenna. I think I will have fun.
One You Tube reviewer could not get it to receive SSB.
That was fixed, I’m not sure what he did but it is working now.
A regenerative one tube receiver can receive SSB, but only very badly. Therefore I only compared AM broadcast reception between FT450AT and one tube radio.
I do own one.
– very good on AM, SW, if adequate antenna, eg for AM an MW loop like from ADDX. Largest bw is 6khz.
– good on FM, a pity they did NOT implement the FM filters 40, 60, 85, 110khz .. and a 0,01 mhz step …
I suppose the radio can be compared to the best of Sangeans MW radios.
I suppose this radio is like a mini computer and can be upgraded via USB port?
I ordered one from eBay it should be here soon. When I was searching you tube on this radio it seem to have decent sound on ssb and nice coverage of shortwave radio for the price point. I got my radio for 79 dollars it included the antenna latest update.