Semier SM-838: Review before donation

OK, I had to have a radio under the Christmas tree, and as the last thing I really needed for Christmas was another radio, I went to the bottom of the barrel for this Semier SM-838 at the sale/coupon price of $9.99 plus tax (battery included). The sale price on Amazon today is $16.49 without coupon. So, is it better than its price-equivalence in Happy Meals?

Semier SM-838 radio
Semier SM-838 (Amazon product photo)

Features

It’s a shirt-pocket MW/FM/SW radio plus MP3 player. It covers the MW band from 520 – 1720 kHz with 10 kHz step, FM from 70 – 108 MHz and shortwave from 2.3 – 21.95 MHz. It comes with an instruction sheet, internal battery, USB-C charging cable, wrist strap and earbuds. The radio has a lighted display with 5 buttons, two side wheels and a switch. The non-user-replaceable lithium-ion is described as 1000 mAh. There is no clock.

Functional features include Auto Tune Storage (ATS) on each band. The instruction sheet doesn’t say how many ATS memories there are, but the number seems to be 50 on each band. It has only 2 digits to the right of the decimal for shortwave frequency display, leaving the resolution at 10 kHz, although it seems like the radio tuning wheel clicks twice between each advance in the display. The instruction sheet says that the SW step is 10 kHz. I was able to receive a strong station on 7.355 MHz when tuning the radio to 7.35 and 7.36.

The instructions say max audio output is 3W, and indeed the radio can be turned up very loud. The battery is only 1000 mAh, so operating the radio at its higher volume levels will deplete the battery fairly soon. This is less of an issue for personal listening or when using the supplied earphones.

This radio is tiny: 101.7 *18 * 56 mm. The antenna is 250 mm (10″).

Operation

The paucity of controls suggests simple operation and that’s the case. The large orange MODE button switches between bands, and can also select SD Card Mode if a card is inserted. The volume control wheel function is obvious, as is the tuning wheel. The PRE/NEXT buttons navigate through the ATS stored stations in radio modes and music files in SD Card Mode. The Pause/Repeat button mutes and unmutes the device in radio mode and has the usual function when playing music files. The SCAN/DELE button initiates ATS.

ATS on this radio scans the entire band, not just international broadcast frequencies on shortwave. The result is that ham radio operators and utility broadcasts can be stored. In practice, with a clip on antenna, lots of noise was stored also. An ATS scan on SW takes a minimum of 5 minutes. I measure ATS scans with the antenna collapsed so that it is not influenced by the time it takes to store individual stations. This radio pauses to play the found station for around 1 second before continuing the scan. ATS on FM tended to store a strong local station on 3 consecutive frequencies.

ATS on MW pointed out a significant problem: it skips all but the strongest stations. When I tried it in the evening, when manually scanning the bands turned up dozens of stations, ATS only stored 2.

I found it very difficult to read the button labels, but there were so few of them that they are quickly learned.

Accessing a particular frequency requires a lot of wheel turning; there is no shortcut. A technique that uses ATS storage to set up presets for broadcast band start locations does not work on this radio because there is no manual storage of presets, only manual deletion.

Given the small size, the MW internal antenna can’t be much. Sensitivity tests suggest that the loop stick is placed horizontally along the top edge of the radio.

I didn’t spend much time with the MP3 function; but I found that songs in subfolders on the micro SD card are ignored.

The radio arrived with only 1 bar showing on the battery, but charged to full in an hour or so.

Performance

The SM-838 shares a problem with many other small radios, noisy display electronics. It’s particularly noticeable on the MW band. There is a rough buzzing sound in the background. Whenever a control is activated, the display illumination comes on for 8 seconds on MW (15 on FM) and while it is on, the unpleasant sound is heard until the illumination goes off. The sound is less on shortwave, but it appears all the time, not just when the display is lighted. It’s not an issue with FM.

I suppose I have to do the Daytime MW/FM Performance test, so for posterity here it is:

Daytime MW reception is poor where I live and the worst radios are lucky to get 3 stations. There is nothing exceptional about this radio on MW, but it’s not the worst I’ve seen, and it should be adequate in an urban area with nearby stations. In the evenings I got a host of MW stations. An external magnetically coupled loop antenna would of course help. Rotate the radio for best reception.

FM on these DSP radios is typically good, and the SM-838 is no exception. I think it has the best FM performance I have seen in its price class. If all you want to do is listen to news or music when you jog, you might be well satisfied with FM performance, but no bass.

I did a brief first look at shortwave in the evening and picked up WWV from my central Virginia location on 10 and 15 MHz with just the tiny telescopic antenna. I got a very strong signal from Radio Marti (a US propaganda station aimed at Cuba) in the daytime. I was able to get a faint signal from CRFX 6070 kHz in Toronto. Shortwave reception varies by time of day and sometimes there’s next to nothing on no matter how good your radio.

While this is obviously a DSP-based radio, there is no chuffing sound when tuning; however, when listening to a weak station, it will drop out entirely rather than sounding weaker.

Small radios with short antennas need a boost to catch much on shortwave, but clipping on a longer antenna can easily overload them. I didn’t find overload a particularly bad problem here. I tried an MLA-30+ clip on in the daytime. This video was Radio China International on 13.63 MHz at 20:14 UTC. I had to get out another radio to verify the exact frequency.

Audio

As I’ve already mentioned, the radio is loud, but one can’t expect much bass from a radio with a 28mm speaker. Here’s a music clip from a local FM station.

As far as I can tell, there is no FM stereo (no mention in the instruction sheet). A good set of headphones didn’t improve the sound much.

Conclusion

It’s a foregone conclusion that without any way to tune shortwave without massive wheel turning, this radio is useless for me, and will be dropped off at the Goodwill store at the conclusion of testing. Nevertheless, FM reception is quite good and it could work for a jogging radio with the supplied earphones because of its small size. Just don’t expect bass.

About Kevin

Just an old guy with opinions that I like to bounce off other people.
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