ATS-20 SI4732 Review: Small is beautiful

The latest incarnation of the diminutive ATS-20 SI4732 Radio Receiver turns out to be a very nifty multi-band radio for travel or your shack. It looks cool, and its performance is respectable. Read our ATS-20 SI4732 Review.

Georg Wiessala – [email protected]

Fig. 1: The telescopic is enough, given what this is, but another aerial can improve things, of course.

Like, perhaps, quite a few of you, I had seen this little radio – and I mean little – appearing on radio blogs and websites for a while now. Initial reviews were not great, so I put off buying for a while. As so often in these cases, there was also the issue of cheap fakes of this product knocking around, which was a bit of a concern.

Half a year later, I tried again; after some online research, I found one at a reasonable price-point, around £ and took the plunge. I bought it from a seller called AllAboutFun, and, unlike many other of these radios, this one was branded as ‘ATS-20’ (Figs. 2 and 3). Quite a lot of these have been sold in Germany, my radio friends there are telling me, so the name was quasi-familiar.

The unit arrived fast, and out-of-the-box, you get the radio a USB charging cable and a simple telescopic aerial. Up and running in no time, first on FM, where the audio quality from the topside speaker surprised me, as did the inclusion of RDS and the metal case. The aerial that comes with it, by the way, is principally for FM.

The table in Fig. 4 shows the key data for the ATS-20, note the 64-84MHz provision and the stepped HF frequency bands. I ran the radio from a power bank, or you could charge it from a USB charger – the input voltage is 5V with a current of 1 A.

Upon switch-on, the initial screen shows the software and developer information: ‘SI473X; Arduino Library; All-in-One Radio; V3.0.7b-ByPU2CLR’. The screen is small – about the size of a postage stamp – but the display is crisp, with information about mode and frequency, step size and bandwidth, volume gain control, and a rudimentary S-meter visible (with my glasses on, mind).

The (small) buttons with a ‘+’ after them, combined with the plastic tuning knob enable you to change parameters. Just follow the instructions in the two-page leaflet; it’s not in Chinglish, and this is, on the whole, an intuitive device. I found that, using just the telescopic aerial, you can achieve acceptable LW and MW reception during the daytime, depending on your location. Hitch it up so a half-decent aerial, and reception improves. I did the overkill-thing and connected the ATS-20 to my Reuter RLA3 (Figs. 1 and 5 for size comparison). RTTY and Fax reception were (just) possible then, on a good day and with the RLA3 or my Wellbrook hooked up.

You might use this as a rudimentary, compact, FM/AM listening post with Lithium-Ion battery for on the road (Fig. 1); or as a ‘monitor’ for just one, or a few, utility data/ voice stations, such as HF VOLMET.

However, in general, I just left the telescopic on and enjoyed medium wave sports coverage on the go. At night, I could receive all my favourite larger short wave stations, for instance, China Radio International, Radio Romania International, and the Voice of Greece, plus a few smaller ones. I was also able to listen in to radio amateurs on SSB, to HF VOLMET, CW, and to RTTY. Sensitivity was good, for what it is, but, of course, this is not a DX machine. However, I had a lot of fun using this small device. There has been some criticism of the bandwidths provided (1.0, 1.8, 2.0, 2.5, 3.0, 4.0, and 6.0kHz), but I did not find this an issue – maybe this is related to an earlier model of this radio.

Fig. 2: Frontal view of the ATS-20 SI4732 Radio Receiver.

Fig. 4: The radio’s key technical specifications, as per its product leaflet. Fig. 5: That’s about the size of it.

As I am writing this, another (ATS-25) model is also out there, offering touch­screen functionality and wideband recep­tion. Go on, treat yourself to one now, tinker a bit and beat any emerging Christmas boredom. But have your glasses ready …

Fig. 3: The rear of the branded version.