ATS Mini versions compared: V3 vs V3S vs V4 vs V4b
Side-by-side comparison of the ATS Mini hardware revisions — what actually changed between V3, V3S, V4 and V4b, what stayed identical, and which version to buy today.
The ATS Mini has been through several board revisions — V1, V2, V3, V3S, then V4 (with V4a and V4b board variants, the latter sold openly as "V4B"). The version numbers suggest bigger differences than exist: the receiver, the processor and the display are the same on every revision, and they all run the same open firmware. What changed is the antenna input stage, a battery bug, the case and the wiring for on-device decoding. Here is the honest comparison.
The comparison table
| V3 | V3S | V4 | V4b | |
|---|---|---|---|---|
| Receiver chip | SI4732 | SI4732 | SI4732 | SI4732 |
| Processor | ESP32-S3 | ESP32-S3 | ESP32-S3 | ESP32-S3 |
| Display | 1.9″ colour (identical) | Same | Same | Same |
| Coverage | 150 kHz–30 MHz + FM 64–108 MHz | Same | Same | Same |
| High-impedance (JFET) whip input | Yes — introduced here | Yes | Yes | Yes |
| Battery drain when switched off | Affected — JFET stage wired to the unregulated battery rail | Fixed (moved to the regulated rail) | Not affected | Not affected |
| CW/RTTY decoding without soldering | No — needs a one-wire mod | No — needs a one-wire mod | Only with a V4a/V4b board inside | Yes — audio tap to the ESP32 fitted at the factory |
| Case | Plastic, AMNVOLT-branded | Plastic, AMNVOLT-branded | Sturdier plastic case | Sturdier plastic case |
| Antenna jack | SMA female | SMA female | SMA female | SMA female |
| Battery | Built-in rechargeable, USB-C | Same | Same | Same |
| Runs current firmware (2.34+) | Yes | Yes | Yes | Yes |
| Works with this app | Yes | Yes | Yes | Yes |
| Still sold | Superseded — buy a V3S instead | Yes (budget pick) | Yes | Yes (current top revision) |
Battery capacity is advertised at around 800 mAh on recent revisions, but we have not verified it per version, so the table does not claim per-revision differences. The exact deltas between the internal V4a and V4b boards beyond the factory decode wiring are likewise not officially documented.
What each revision actually changed
V3 added the high-impedance JFET input stage that makes the short whip work as well as it does — and shipped with a real flaw: the stage was wired to the unregulated battery, so early V3 boards drain a few milliamps even with the radio switched off. V3S is the corrected board, and the reason "buy V3S, not plain V3" is standing advice. V4 brought a sturdier case and audio improvements. The V4a/V4b boards add one thing more: the SI4732 audio output is wired to the ESP32 at the factory, so the radio decodes CW and RTTY on its own — a firmware feature that older boards can also run after a one-wire solder mod. None of these steps changed how well the radio hears; the front end’s character and the display are the same throughout.
Which one should you buy?
- Starting fresh: the V4 (V4b board) — current revision, no soldering for decode features, and the version most listings sell. See the receiver page for the checked listings.
- On a budget: a V3S — the same reception and the same firmware for less money. You give up the factory decode wiring and the newer case, nothing else that matters.
- Avoid: a plain V3 (the battery drain), anything sold as "V5" (the makers say V4 is final, so V5 listings are fakes), and unbranded metal-case units — counterfeiters reportedly drop V1-class boards into metal shells.
Firmware: the great equaliser
Every revision here runs the same open firmware, and that matters more than the board differences. Bluetooth control, fast direct tuning and this site’s USB remote all arrived in firmware 2.34, and a V3S flashed to the current release has every one of them. The features that genuinely need newer hardware are few — essentially the solder-free CW/RTTY decode path. Details in firmware versions, and buying-checklist notes in the receiver guide. Once you have any of them on your desk, connect it to this app — the experience is identical.
Recommended gear
Frequently asked questions
- What is the difference between the ATS Mini V3S and V4?
- Reception is the same — both use the SI4732 receiver, ESP32-S3 processor and the identical 1.9-inch display. The V4 has a sturdier case and, with a V4a/V4b board, factory wiring that lets the radio decode CW and RTTY without a solder mod. The V3S is the corrected V3 board and the usual budget pick.
- Should I avoid the plain V3?
- Yes, prefer a V3S. Early V3 boards wired the JFET antenna input stage to the unregulated battery rail, so they drain a few milliamps even when switched off. The V3S moved it to the regulated rail and fixed the drain.
- Is there an ATS Mini V5?
- No. The makers consider the V4 design complete and have said they have no short-term plan for a V5, so any listing selling a "V5" should be treated as fake.
- Does the V4 have a better display or better reception?
- No. The 1.9-inch colour display is identical on every revision, and the core SI4732 reception is the same. Listings that sell a newer version on a "better display" are marketing; the real differences are the case, audio details and the decode wiring.
- Do all versions run the latest firmware and work with this app?
- Yes. V3, V3S, V4 and V4b all run the same open firmware. Flash 2.34 or newer and every version gets Bluetooth control, fast tuning and the USB remote this app uses.
- How do I spot a fake ATS Mini?
- Genuine plastic-cased units carry the AMNVOLT name on the case. Be wary of unbranded metal-case units (counterfeits reportedly hide V1-class boards in metal shells) and of any "V5" listing, which does not exist as a real product.