439
Item nr.
Pocket construction kit.
| Production | The Netherlands, 2016.
Price was 4€. |
|---|---|
| Bands | MW (525-1605kHz), TV/FM (76-108MHz). |
| Semi- conductors | CD9088 (FM tuner), TA7642 (AM tuner), TDA2822M (AF amp), LED. |
| Cabinet | Plastic. Size 10x6,5x2,5cm. Weight 73gr. |
| Power | Batt 2xAA. |
| Documents | Schema. |
| Obtained | 3/2016 from Aliexpress.com. |
|---|---|
| Condition | 6. |
| Disposed | Scrapped 5/2016. |
The radio came as a small construction kit, complete with all the electrical parts (except for one 4R7 resistor) and cabinet for just 4 euros. Assembly is probably supposed to be easy, and fortunately it came with instruction sheet, fully in Chinese! Well, at least I could look at the schema, for the rest it was all Chinese to me. 
Soldering the PCB was quite OK, but some of the parts can be mounted in two orientations and with the wrong orientation, the radio does not work. The three elco's must be placed with the minus side on the whitened half-circle, which I had correctly guessed. I had soldered the LED incorrectly, but when the light didn't blink I could swap it easily. For the CD9088, the drawing on the PCB was with a dent in one short side of the rectangle, while the chip actually had no dent but a dot in one corner. I chose to place the dot closest possible to the dent, which proved correct, fortunately. The tuning cap has four sections, of which just two are used! The two sections of 33pF are meant for FM and these must be oriented towards the CD9088. The sections of 150pF and 100pF are for AM, and these must be at the edge of the PCB.
I broke the lead of the loudspeaker, but I managed to open the speaker and fetch wires near the coil, after which the speaker worked again! Perhaps with smaller sensitivity, but alas. The radio is very difficult to align, because once inside the cabinet one cannot touch the screws anymore.
All in all a nice project, but I was not 100% satisfied with how I assembled it. So I ordered a new kit (Ali will deliver this stuff to your home for 4 euros!) and used the PCB as the FM unit of an experimentation project.
