Antiphase spiral coil transmitter + receiver

[WM6]

For those interested in spiral coil transmitter here one simple transmitter schematic, which anti-phase frequency outputs can be set from down to 1Hz to up to 10MHz.

Transmitter frequency is set by C1 and C2, by rule:

C1 = C2

Par example

- to get frequency of 1Hz then C should be about 50uF
- to get frequency of 10MHz C should be about 10pF
- to get frequency of 1MHz C should be about 200pF etc.

Coil inductance of receiver should be calculated according transmitter set frequency.

Telescopic antennas are all connected over capacitors (TX with 47nF, RX with 47pF respectively).

IC1 of receiver is symmetric supplied by two 9v batteries.