| Author | Message | ||
     Anonymous |
I would like to know which of the radios that are listed here is the strongest because I am building a radio receiver for a school project. Also, would adding more batteries to what ever receiver is the strongest make it stronger? | ||
| Simon Quellen Field (Sfield) |
By "strongest" I presume you mean some combination of loudest and most sensitive. The Three Penny Radio is the best of the collection. Adding more batteries won't help. Adding a big antenna and a good ground is your best bet. Use the same trick as the 10 minute radio. Wrap one turn of wire around the ferrite, and connect one end to ground and the other to a long wire. | ||
| James Stanley (Stanley) Junior Member Username: Stanley Post Number: 5 Registered: 4-2007 |
Sorry to hijack the thread, but I have recently acquired a Germanium Diode. I connected it to some high impedance earphones like in the example, with a good ground (middle pin of a mains socket), and held the other end of the earphone lead. All I hear is crackling. Is this indicative of too low impedance or some other problem? The earphones I have are high impedance but not piezoelectric. I'd rather not buy some piezo ones if the problem is elsewhere. Thanks, James Stanley EDIT: I am talking about the two-component radio here, by the way... (Message edited by stanley on July 1, 2007) | ||
| Simon Quellen Field (Sfield) Senior Member Username: Sfield Post Number: 1716 Registered: 12-2004 |
Try a long wire antenna. You may not be close enough to a strong radio station to pick it up just using yourself as an antenna. | ||
| James Stanley (Stanley) Junior Member Username: Stanley Post Number: 6 Registered: 4-2007 |
OK, thanks a lot! When I do that I can hear the 50Hz tone of the mains electricity! I'm going to solder it together so that I can have free hands, then I'll try it on a water pipe, and I'll also try using a walkie talkie to transmit with. Thanks Simon! | ||
| James Stanley (Stanley) Junior Member Username: Stanley Post Number: 7 Registered: 4-2007 |
Aaaargh! I still can't make it receive radio! I even tried doing the first radio, the one with the coil and the diode. I wrapped about 20 turns of wire around a beer bottle, and I used a 3m antenna. When I did this I didn't even hear the crackling. Is it likely that my diode is broken? Or that I haven't got a long enough antenna or coil? (I don't have any more wire). If I recall correctly, my Dad bought a kit crystal radio a few years ago, and he could never pick anything up on that. Unless there's anything else you think could be wrong, I'll scour the internet for all the advice I can get. Thanks, James Stanley | ||
| Simon Quellen Field (Sfield) Senior Member Username: Sfield Post Number: 1720 Registered: 12-2004 |
Twenty turns is not enough, and a 3 meter antenna is not enough. You didn't mention what you were using for a high impedance earphone. You will know the earphone is good if you can hear crackling when you touch its leads together. The kits we offer for sale come with a 100% satisfaction guarantee. | ||
| James Stanley (Stanley) Junior Member Username: Stanley Post Number: 8 Registered: 4-2007 |
OK then, I'll see about getting a bit more wire. The headphones I'm using do not crackle when I touch the leads, so I'll get better headphones too. They are high impedance morse operator headphones that my Dad used in the army about 20 years ago. Thanks. |
