The British Caving Association

HeyPhone project : After several email exchanges with John Hey and data collected on GREGJ, I would like to resume and give you some technical answers concerning the HeyPhone project. 1 - Toko coils : the original variable coils, L1, L2 and L3, can be replaced by fixed coils like Inductor axial 330µ...

Hi,

I am looking for 5.568 MHz quartz crystals used as local oscillator in the Heaphone project but I cannot found any crystal at this frequency.
Anybody has an idea ?

Greetings from France,
--
Daniel.