DIY Shortwave radio

A little quick Shortwave radio I put together just for fun, took 1-hour to create on the breadboard, and a little more fiddling with the various coils for different bands. Quite fun, and a lot better audio quality than my previous attempt.

This one uses 4 transistors, basically just an "amplifier" construction connected to a diode, coil and a few caps + one long antenna wire. Not getting ground from a transformer, it just uses a 9 volt battery.

[rEdf]

I just built a regnerative 2 tube set it gets great selectivity as wall as sensitivety compared to a SW crystal setup I am sure there are lots of transister regenerative SW radio schematics as well. or even a superhet design too.

[TommyHelgevold]

Indeed it had.

I've modified into a regenerative now by adding a 5'th transistor, a BF240. Very VERY noisy, have to work on it a bit, and then I'll upload a video when it's got a usable sound quality.

[TommyHelgevold]

@thewii552
Well, the construction is awfully simple, basically a transistor amplifier connected to a crystal-diode setup (no actual crystals used), but the same way a crystal receiver is constructed, check wikipedia to get the idea, I can't bring you links here, but google for crystal radio and click on the wikipedia link.

[TommyHelgevold]

@AbnormalEthnos, it really wasn't that hard. It's basically a Philips type 4-stage transistor amplifier (which you can find schematics on the net, google it) in combination with an absolutely standard crystal radio receiver. In other words - all you do - is to combine these two principles. You can't really make any mistakes. Re-generative receivers however...is a different story.

[thewii]

so crystal radio == SW radio? with a small coil?

[joeypc]

Oh I'd love to see the schematic. Could you please show me the schematic ?
Thank you !

[monkeyssj]

cool, so took get the circuit diagram

[TommyHelgevold]

@paulthez0mbie,
Well, since this was mostly built with parts I already had in my workshop, the cost was sort of ZERO. But if I were to guess the price of the parts, I know that the Breadboard itself cost about 30 bucks (they can be gotten smaller and cheaper), speaker...a dollar, 4 bucks worth of components I guess. All in all..you could probably build this for less than 10 bucks if you do some wise shopping around ;)

[adeshization]

i would really like to get a schematic for this, ..., neat n'nice

[choppergirl]

You should attach a digital frequency counter to it (you can get a cheap used one off ebay for $25) so you can see where you're tuning and figure out your frequency coverage with the number of windings you're using. Maybe wind several more coils attached to a selector switch so you could switch bands for more coverage. Also post a schematic.

[TommyHelgevold]

@monkeyssj5
Thanks, there will probably be a much better video for this stuff in the future, so stay tuned ;)

[hle]

I see 30 Winds on the coil. Where do you think you were receiving at?
Do you have a schematic too? :-) Thanks !

[whysguy]

I am looking to build my own front end radio to use with the iPad app "iSDR" can anyone point me in the right direction of a relatively inexpensive kit or DIY tutorial.