DIY Radio Kit CF210SP AM FM Crystal Radio Kit Band Radio DIY Electronic Kit

I bought this item for my youngest grandson thinking it would be a goo learning experience for him. I thought it would be a genuine crystal radio like the ones I played with when I was a kid. You know, where you probed a crystal with a cats whisker til you found a nearby radio station you could listen to through headphones. No, nothing of the sort. Its a miniature radio kit replete with a printed circuit board and electronic components and a miniature speaker. Still, though, I thought this might be a good teaching tool. To my dismay the instructions were written in only kanji characters, undecipherable to an 8 year old kid, The kit turned out to be totally useless and wound up in the trash.

I've recently built several of these. These kits are very inexpensive for what they are, but are not old style crystal radios. Rather, they use nomodern chips- one for FM band, one for AM band, and one audio amplifier in bridge mode driving a speaker or headphone jack. The design is quite clever mechanically, but requires intelligence to put together as the instructions are in Chinese. My opinion is that if you are talented, and not "all thumbs", you can figure the assembly out yourself. You can also look up the chips on the internet, and follow the illustrations on the included 2-sided sheet. If that seems like too much, then you may not be a good candidate for this type of work. Further, you need to have good soldering skills, eyesight or a magnifier, as with any modern day electronics. The parts are all labeled, but if you can't read some resistors, you could measure them with a volt-ohm meter. If you mess up and ruin the circuit board by resoldering, you can buy another kit at this price! I do have several suggestions. 1) Make sure all parts are properly located in an area BEFORE soldering(welding). 2) The LED must be adjusted for the correct height of the circuit board(PCB) which can be determined mechanically. If it's too high, when you assemble the case, you will push the soldered lands off the PCB, thereby making repair difficult as other components are connected in close proximity. 3) I used two different sized soldering iron tips- 1mm small for tight spots and 4mm for tuning cap, volume control, etc. 4) the speaker connections on the PCB are best made at the phone jack and can be confusing due to markings there- note the semicircles. 5) slip a thin wire through the antenna mount after soldering it to the PCB. Avoid soldering to the antenna. I found drilling case holes to coincide with the trimmer screws on the tuning capacitor to be necessary in order to adjust the FM station frequency alignment to the the face plate markings. I also had to spread the 8T5 coil(L 2) to get the lower parts of the FM band in alignment, and the lower trimmer screw for the high part of the FM band. These are things radio guys already know. You will find the AM tuning to be broad as this is a TRF AM radio design and the Q of the single tuned coil establishes the selectivity. I think it's a great, but simple design. It is not waterproof, nor is it like a radio for grandma to use on her nightstand!

Nice little kit, but instructions are Chinese only. No English.

A crystal radio does not use batteries, it is powered by the transmitted radio signal.you

It’s awesome my grandson likes to put stuff together he put it together and listens to music on it it’s cool

Not a crystal radio, just an FM/AM radio, also in Chinese, I had Google Lens translate, I'll share the translated copy. Aslo, too expensive for a unassembled radio, you can find some at similar prices that are assembled and sometimes cheaper.

My husband built a crystal radio when he was a boy, so I wanted to get him another kit. He was pleased and is looking forward to putting it together. Unfortunately, all directions are in Chinese, although there is a diagram.

I have bought several of these just for parts alone, great for making a simple crystal radio.