crystal radio

Time for me to pick your brains.
My boy turns 7 tomorrow and we got him a crystal radio kit as one of his presents.
Got it all together and nothing. It has been a long time since I have made one, so I have no idea what is wrong with it.
The germanium diode measures around .287 and I have continuity I think everywhere necessary.
Can someone give me a couple of suggestions please?


Thanks I know atleast several of you know how to help.

mut

I bought a crystal kit from radio shack a few years ago. You have two wires, one for ground that I hooked to a water pipe and the antenna I ran along the celling and back. The longer those wires are the better. I got a faint signal on the ear piece and it was picking up stations on the AM dial. WRVA came in loud and clear, not much else. It used a tiny tiny diode and had a varable capaciator to tune it and a ferrit coil antenna.

I second Cobb's advice about a good ground and a looooong wire antenna. I built a crystal set as a kid and as I recalll I could only pick up a couple of really strong stations. It did work though and I was amazed!

Have you tried measuring the diode in both directions to make sure it's not shorted?

Happy B-Day Photon Wrangler!

Could you take a picture of your connections?

Likewise when I built one some years ago, only got the one local station and it was faint.

I made one of those too. Yes, you do need a good ground. I have one AM station very close by in Pomona that I was able to pick up but nothing else.

Other possibilities I did; make a larger antenna to pickup more stations. Make a small amplifier for the sound output.

Speaking of this, I wonder where I even put that set. I'll have to search my junk box.

MScottz said:

Happy B-Day Photon Wrangler!

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Thank you! Older but not necessarily wiser! :laughing:

Thanks and habby b day. Yeah, the stock antenna the kit came with didnt cut it. I think I read somewhere the best antenna was like 1800 feet, so I did the next best thing and got a 100 foot roll or small diameter wire. I ran it out a window and along the top of the fence a few times. It made the one local station stronger to the point you didnt need to jam the ear piece in your ear to hear it. It used a piezo electric element in the ear piece.

If you have a TV antenna hook it up to that. Chances are it points in the right direction.
I did that many years ago with a cheap transistor radio which picked up a few local AM stations.
with the antenna I couldn't find anyplace on the dial wher there was not a station.

I had a cable contractor that was less than professional tell me to hook a radio antenna to the cable wire and I could get signals and stations from all over the US. He said he does it and listens to this station in PA.

cobb said:

I had a cable contractor that was less than professional tell me to hook a radio antenna to the cable wire and I could get signals and stations from all over the US. He said he does it and listens to this station in PA.

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Umm, right. And make sure you have some milk and cookies ready for the compliance guys when they discover all that signal leakage. And if there's an airport nearby, you might have to pacify the FAA also.

:tsk:

PhotonWrangler said:

Umm, right. And make sure you have some milk and cookies ready for the compliance guys when they discover all that signal leakage. And if there's an airport nearby, you might have to pacify the FAA also.

:tsk:

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not to mention all you will hear is noise and video (sync pulse) buzz

Thanks guys.
I knew you all would have some good advice.
We didn't get to do any more with it today. Too much cubscout things going on.
But we will work on it some more tomorrow......I hope. I just hate leaving things not finished

Thanks again.
mut

I remember the one I had as a child. I could only pick up stations if I stood by a utility pole that supported a large transformer or connected the ground clip to a metal fence.

Here is a link to a page with one of them on it.

mut

Is there an easy way to amplify it?

mut

When I was a child of 9 or 10, I built one using a chunk of galena (lead sulfide I think) as the diode, and it picked up both AM stations that were broadcasting at the time (KJNO 630 and KINY 800).

I think KJNO had a broadcast power of 1,000 watts and KINY was 5,000 watts.

mut said:

Is there an easy way to amplify it?

mut

Click to expand...

There might be but it would probably take the fun out. This link on a
foxhole radio might be of interest.

Hmm, I've got a chunk of galena laying around here somewhere...