A crystal radio is often a kid’s first introduction to building something electronic. [Billy Cheung] is a crystal radio builder who wants to “make crystal radios as easy to use as regular radios.” He’s built many sets, but his latest is one that not only fits in a matchbox, but uses the matchbox as a variable tuning inductor.
There’s no oatmeal box in this design and just a few components. The matchbox contains some ferrite rods and two different windings. By moving the inner part of the matchbox, you can tune different stations. Although the design calls for two fixed capacitors [Billy] found he had enough self resonance (presumably from stray capacitance) that omitting them didn’t hurt his reception of strong signals.
[Billy’s] web site has a variety of crystal radio builds. You can find radios built into pens and even some capable of receiving FM stations. Because of their simplicity, many people have built them from junk they find lying around.
Murloc Sounds on AM radio?! What kind of crazy station is that? :D
Morlock Sounds? Must be some underground station.
lol i heard salad fingers on FM once
I gotta take a little time, a little time to think things over
I better read between the lines, in case I need it when I’m older
Now this mountain I must climb, feels like the world upon my shoulders
Through the clouds I see love shine, it keeps me warm as life grows colder
Better hurry up cause AM’s going down the tube. There is a way of making a slope detection crystal work on FM vhf.
I hear about this alot, how is it done?
I mean actual practicals, I understand the theory.
The linked site has some FM examples.
http://theradioboard.com/rb/viewtopic.php?f=2&t=6518
is a dead link, darn.
In case anyone is looking for Billy’s web site after all these years, http://billycdiy.blogspot.com/ (archive.org: https://web.archive.org/web/20231223180218/http://billydiy.blogspot.com/) is gone but it looks like he has most of the same material up at http://billycdiy.blogspot.com/.