Getting Back into (Crystal) Radio sort of

[KG4CGC]

I was under the impression that ants only needed to use mandibles.

[PA5COR]

Look at the last schematic diagram, the double diode detector.
More sensetivety, more output too.

[kd8dey]

Look at the last schematic diagram, the double diode detector.
More sensetivety, more output too.

Seen those on another site :)
On that last one they list L1-L2 as 60 turns and 30 turns of litz.

I would have been better if they had listed a little more info on the coil. IF I remember correctly The tap point depends on sensitivity vs selectivity and builders usually tapped at about the top 1/3 of the coil length as the best compromise which this one follows, SO using the L/C formula and the 1/3-2/3 coil split you should be able to place it where you want it in the bands :)

[KA5PIU]

Hello.

If you are into active devices you can build a tube type radio that runs on 12 volts.
http://makearadio.com/visitorsprojec...tube-radio.php
Yes, if you are so inclined you can build a 5 tube AC/DC that runs on 12 volts AC/DC
The trick is to do all of the diodes in solid state and think of the output section with a transistor in mind, or not.
Think of how a switching power supply works, it will run on DC as well as AC.
Computer supplies that have failed are very common and can be had for nothing most of the time.
This is something to think about once you want something more advanced but are concerned of safety.
I no longer connect the filaments in series and run off 110 but run everything off 12 volts with a switcher somewhere in line.
The absolute highest voltage I want to see is 48 volts nominal, something I can boost to whatever I want while limiting the current internally.
I can get up to 3 watts out of a TV sweep tube with very much safe voltages and current.
This being 1/2 of a push-pull circuit and a transistor providing up to 12 watts I can get that tube sound with transistor volume.
Dump that into a quality single cone speaker and you have it made.
Farm radios ran on as little as 32 volts and were common, in fact the conversion was sometimes done at the point of sale.
http://www.vintagetunesradios.com/an...-for-sale.html
This gives you a beseline to work with.
Note that I do not approve of anything like the "Solid state B+ supply as this is a hot chassis design.