I’ve hesitated to talk about the Tecsun R-9700DX radio much because while other reviewers like it, I was disappointed, and I didn’t want to bad mouth a radio unfairly. In this article, I’ll also refer also to my vintage Panasonic RF-085 receiver that I bought around 1985.
I’ve been listening to shortwave radio for a very long time, and I have owned over 100 radios. What I expected from the R-9700DX was a good example of where analog technology had reached in the 21th century. I expected to be impressed but I wasn’t.
Let’s start with sensitivity specifications. Here are the values for two radios:
|Band||Tecsun R-9700DX||Panasonic RF-085|
|MW||< 1 mV/m||200 µV/m for 50 mW Output|
|FM||< 10 µV||3 µV for 50 mW Output|
|SW1||10 µV for 50 mW Output|
|SW2||8 µV for 50 mW Output|
|SW3||5 µV for 50 mW Output|
|SW||< 30 µV|
That doesn’t help much because the Tecsun doesn’t specify a standard, and the Panasonic uses an uncommon one. I’ll assume the Tecsun is using S / N = 26dB, something quoted by Tecsun for other radios, and if so, the R-9700DX lags behind Tecsun’s DSP-based radios like the PL-330 and its digital display analog radios like the PL-660, both with 20 µV on SW and 3 µV on FM. MW is the same 1 mV. My personal observation is that the R-9700DX isn’t particularly sensitive. I get 7 MW daytime stations (weak signal area) on the R-9700DX, 12 on my Tecsun PL-660 and 20 on the Panasonic (that blows everything else away on MW). I mistakenly thought that a big heavy radio would have a big ferrite antenna and have good MW reception, but it really doesn’t. Shortwave performance was mediocre too.
Tuning range is a consideration. The Panasonic tunes from 2.3 to 18 mHz in 3 contiguous bands. The Tecsun covers 3,9 to 21.85 mHz in 10 non-contiguous bands; while the tuning range is larger, there are gaps between the bands on the Tecsun, so it’s a bummer that it can’t receive WWV on 10 and 15 mHz or CHU on 3330, 7850 and 14670 kHz, while all are there on the Panasonic. And what about MW? I can excuse the Panasonic for its limited MW band given its age, but how could a modern radio not cover 1620 – 1710 kHz?
I found the R-9700DX tuning knob stiff, but without noticeable backlash.
I told myself once that I would never buy another radio with an analog dial because it’s hard to identify a station with only an approximate frequency. This radio is not only analog (and approximate) but also inaccurate. A detailed test of all the bands (using a signal generator and frequency meter) found some of the frequencies were just wrong. The video following is a booming signal on 11930 kHz from Radio Marti (pretty much the strongest daytime SW station here) around 18:15 UTC with the Tecsun’s whip antenna. You can look for yourself, but I say the dial is not accurate (SW6 band) for that frequency. The dial pointer is above (lower frequency) than the 11.9 mark.
On the plus side, the Tecsun has a “big radio” sound and is pleasing to listen to for music on FM. It has a nice warm vintage dial light.It has a Local/DX switch. It comes with a power supply, case, manual (half a sheet of paper printed on both sides), earbuds and an external antenna. Both the Tecsun and the Panasonic have connectors for an external antenna and both can use it on MW.
I went outdoors in mid afternoon and hooked my 20-foot wire up a tree (WUT) antenna to the radio’s external antenna jack. I switched to SW3 (49m) and tried to find CFRX on 6070 kHz. What I got was very strong SSB transmissions all over the band. CFRX was not to be found. Figuring the radio was overloaded because those signals were not really on those frequencies, I flipped the DX switch to Local and got basically nothing but noise, no CFRX.
Then I disconnected the external antenna and tried the whip antenna alone. That got a decent signal from CFRX.
Then for one final experiment, I clipped on the long wire instead of using the antenna jack. The SSB overload was barely there and I could get CFRX.
Note: I didn’t have the overload problem (if that’s what it is) on higher-frequency bands.
For videos comparing the Tecsun R-9700DX to a bunch of other radios, check these out:
The Tecsun R-9700DX is an OK radio, but I was expecting something special. Its performance is lackluster, but I suppose reasonable for a $45 radio ($60 on Amazon). Some have suggested that the Chinese version (which I have) may not be subject to the same quality controls as the English version and perhaps uses cheaper components; this is just speculation as far as I’m concerned. Maybe I just got a bad one, but everything works, just not as well as I’d hoped. The radio was introduced 21 years ago, so who knows how many versions it has gone through in that time.
I couldn’t find a manual online, so here is a photocopied manual for the Tecsun R-9700DX, such as it is, for posterity, and for reference here’s the manual for the Panasonic RF-085.
Performance hint: the Local/DX switch applies to both the external and internal antenna.