I sold about 80 radios on eBay, but there were just a few that nobody wanted. I went through those to see if there was anything worth saving from storage. One radio looked like it might be worth further study, a Kaide KK-MP903.
It’s a remarkably simple radio, with only 4 buttons, a volume wheel and a tuning wheel, but it is an 11 band radio, clock, alarm, calendar and MP3 player. The radio uses 2 AA batteries and has an earphone jack and a jack for an external 3V power supply. The antenna extends to 17.5″ and swivels allowing it to be vertical when the radio is on its kickstand, a fob on the end of the carrying strap.
It has AM (MW), FM, FM1 (70-88 MHz) and 8 shortwave bands from 5.95 – 21.85 MHz. The chart later on shows discrete ranges for the bands, but in practice, there are no gaps between bands; coverage is continuous. Tuning is digital. Repeatedly pressing the FM button switches between the FM and FM1 band. Repeatedly pressing the SW button sets the tuning to the start the next shortwave band.
Inserting a micro SD/TF card in the slot in the side converts it to an MP3 player. The same 3 radio operation buttons work as MP3 player controls, with function labels on the top of the radio.
This description was found on the internet, translated by Google from simplified Chinese:
The performance improvement brought by DSP technology to this radio section product: digital filtering, strong selectivity, no tandem; full-band frequency tracking and locking technology, no image and frequency drift phenomenon in short-wave reception; digital processing technology makes the sensitivity comprehensively improved, There are many receiving stations; built-in digital power amplifier, high power, low distortion; FM stereo output.From https://www.gdjyw.com/myfile/count.asp?id=512
Also at the same site these specifications:
- Frequency coverage
FM: 87 -1 -108 +1 MHz
MW : 520 -60 – 1710 +60 kHz
SW1: 5.95 – 6.20MHz
SW2: 7.10 – 7.30MHz
SW3: 9.50 – 9.90MHz
SW4: 11.65 – 12.05MHz
SW5: 13.60 – 13.80MHz
SW6: 15.10 – 15.60MHz
SW7: 17.50 – 17.90MHz ( Shortwave frequency coverage is not narrower than the above requirements )
- Noise limiting sensitivity
FM : 30 Noise Limit Sensitivity 10 dBu
MW : 26 Noise Limit Sensitivity 70 dBu
SW : 26 Noise Limit Sensitivity 35 dBu
- Signal-to-Noise Ratio
FM: 98 MHz ≥ 50 dB
AM : 1000 kHz ≥ 40 dB
- Selective MW: 1000 kHz +/- 9 kHz ≥ 40 dB
- FM stereo separation: ≥25 dB
- Maximum current consumption: ≤ 180 mA
- Maximum output power: ≥100 mW, maximum distortion ≤ 20 %
- Size: 124*77*21mm
A brief test using just the whip antenna picked up many stations on shortwave. Here’s Radio Romania International on 7420 kHz on June 5 at 0010 UTC heard in central Virginia.
The functions of the 4 buttons were easy to discover. There are basically 3 sets of functions, when the radio is off (clock, calendar, alarm functions with dates and time selected with the tuning wheel), when the radio is on (band selection), and when the radio is on and a micro SC/TF card is inserted (next track, play/pause, previous track). Counterclockwise rotation of the tuning knob increases frequency.
The small speaker does not produce rich sound on radio, nor is there any significant bass response even with good earphones. Sound is much better playing MP3 files.
The display is large and easy to read. In radio mode, the band is displayed along with the time and frequency. There is also a stereo indicator for FM. When the radio is first turned on, a button is pressed, or the tuning wheel turned, the display is illuminated with a pleasant orange glow. When the radio is off the radio displays the date and time. In MP3 mode, the radio displays the time of day, the track number and the elapsed time played in the current recording. It does not play files in the WMA format.
My only puzzle is how (if possible) to set the AM tuning step to 10 kHz instead of 9. I’ve found virtually nothing about this radio on the internet. I probably bought it on eBay a dozen years ago. One Chinese exporter still sells it for $25 (one presumes it’s legit).