Interesting Chinesium SI4732 Shortwave/Air/FM

[syfr]

https://www.amazon.com/Receiver-Airband-Portable-Handheld-Recorder/dp/B08ZDHT7LY/ref=psdc_172653_t2_B08Z8L9ZYZ

Anyone seen any reviews?

It's cheap enough I might take the gamble. After all:

Application: Si4732 radio receiver suitable for outdoor camping, listening to radio music in the kitchen, it is a necessary condition for participating in the parade and family life

[ChrisSmolinski]

The guts of the radio is the SI4732 IC, which basically does all the RF stuff: https://www.silabs.com/documents/public/data-shorts/Si4732-A10-short.pdf

Lots of variants of the radio on eBay as you may expect.

Or buy the IC and build your own! https://www.mouser.com/ProductDetail/Silicon-Labs/SI4732-A10-GS?qs=p9T7GgSe1IFCUks4Oy6aSA%3D%3D

Cheaper here https://www.semiconductorstore.com/cart/pc/viewPrd.asp?idproduct=55203

[~SIGINT~]

I don't know, it looks pretty sketchy to me. Not even any pictures with the unit powered on so you can evaluate the display.

Plus; what is that FM/AM(SSB) recessed switch by the antenna input connector?
No run-time on the battery;
"FM supports earphone antennas" --- maybe that's what that switch is, use the earphones as a FM dipole?;
"PCB retains the SI4735 package, users can replace the chip by themselves, and the software is compatible." What you talkin' about Willis?

I could go on and on here. No thanks. $68.69 + $99.00 shipping to Canada. Forget it.

[syfr]

Found a review or two on Youtube...one even in English. Might give it a go. I saw that note about replacing the "chip" (what?!) .

As usual , there's the general clunkiness of operating all radios with few knobs but a lot of buttons (whether it's Icom or NoNameesium)

[~SIGINT~]

If you do end up with one I'm sure we would all be curious and like to hear about it.

If you are not interested in the FM, air band stuff, I.E. shortwave only, you can't go wrong with the BELKA-DX. I have had one since last November and it is a great little box. The only "I wish" thing about it is if it was not limited to 1.5 - 31 MHz. Like most BELKA users, we wish it went down to 500 kHz to cover the AM band. Even if it tuned down to zero with reduced performance I would be ok with that. I have slipped that radio in a coat pocket with earbuds on and had "HF on the move" listening to broadcasts while taking a walk. I even take the radio on bike rides down the trails and stop for 10 minutes or so and DX from various locations. I'm truly having a blast with that radio.

[redhat]

Why the interest in this, form factor perhaps?  I would guess this is the chipset used in all the Chinese cc radio clones?

+-RH

[NJQA]

While they say this is an “Airband” radio, none of the Amazon sellers, nor the SI4732 data sheet, show that it has coverage of 108 thru 136 MHz.  I guess they mean the SW aviation frequencies, not the VHF ones.

[RobRich]

I have one on order via eBay. It could take awhile to arrive from China. I will try to remember to post some feedback here.

[~SIGINT~]

You can follow this post for further details and reviews.

Any thoughts on this inexpensive Si4732-based receiver?
https://swling.com/blog/2021/04/any-thoughts-on-this-inexpensive-si4732-based-receiver/

[RobRich]

Copy-and-paste from my SWLing post....

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.

[RobRich]

Marc at swling noted it reports a HL-340 USB-Serial adapter when probed under Linux.

Looks like we might have a potentially rather hackable radio assuming it proves popular enough.

[syfr]

Reviews are starting to appear and they're not good.

I ordered a Belka (whose reviews are quite good!)

[RobRich]

It is a project radio, and that is how I went into the purchase. Think more or less an assembled kit, and you get to "fix" it to some usable state.

Still waiting on mine, but I did get shipping info recently, so maybe it will arrive in a couple or so weeks.

I did a quick skim of a Si473x community awhile back. Somebody was working on software. Spotted info about cleaning up and stabilizing a similar (or same?) design with filtering caps.

Assuming mine even works at a basic level, I intend to add more power filtering, basic ESD protection, and perhaps some type of input matching.

All that said.... yeah, definitely instead buy a known decent radio if actually wanting something usable out of the box. :)

[RobRich]

Received mine earlier today. Connected it to my 9' vertical, turned it on, and skimmed some frequencies.

Sounds decent on AM and FM broadcast bands. Plenty of volume. Has several bandwidth options, multi-step attenuation, etc.

The VFO feels about the same as a basic portable. AFAIK, it is only soldered to the PCB, so that probably needs some reinforcement. Especially if pushing on it for the SSB BFO and whatever else it does.

I have yet to open the radio for a quick look. Maybe later today. At minimum it is likely getting a couple of diodes for basic ESD protection, then I might look into adding a few filtering caps on the internal power rails.

[RobRich]

Still have yet to open the radio, but I did get around to updating the software.

https://github.com/pu2clr/SI4735/tree/master/examples/SI47XX_KITS/AliExpress

Much better user interface now. :) Other changes include being able to tweak or disable soft mute, finer grained attenuation, and a few options being moved to the encoder instead of multiple button presses.

Currently using it to listen to a 40m SSB net via the 148' LoG. Sounding and performing about the same as any other SI473x portable in the sub-$100 segment IMO. The SSB highpass is a little high for music, thus losing some lows, but generally okay for voice comms. The internal speaker response seems rather narrow anyway. Of note I actually like the form factor. I have been using it as a small secondary receiver on top of my Kenwood R-2000.

I plan to drop in a 1M resistor and a couple of diodes for at least basic ESD protection. After looking through my parts, I had to order the diodes, so I will take a closer look inside after receiving them.