The VHF Ear – Amplified Crystal
Popular Electronics July 1957
This is an interesting circuit a for several reasons
Its a Crystal Receiver intended for VPF
It uses a very small coil
It uses a very small antenna
Very little Adjustment is provided via the 9 pf variable capacitor
If this were built today, several changes are required
Adjustment for current frequencies, updated transistors, and maybe a change in impedence to use modern headphones, but a crystal earphone seems like a natural fit – Lots of good experimenting!
The VHF Ear – Amplified Crystal – Popular Electronics July 1957
