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Extend your coverage down to 10 kHz with this Very
Low Frequency Receiver, 10 - 150 kHz, direct conversion for morse, 50 k ohm input
impedance for 15 m antenna, needs 12 V at 10 mA, 4 x 7 x 13 cm, 250 g.
| "very interesting to hear stations on VLF", FR in High Wycombe,
Bucks. |
| "excellent little set", THR in Worthing. |
| "neat and works very well", CGM in Jersey. |
This fun-to-build kit used to include all parts, tinned drilled fibre-glass pcb, case, connectors, screws etc
as well as detailed assembly and operating instructions including circuit description and diagram.
Please e-mail martincambridge@live.co.uk
for
any extra parts now neeeded.
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VLF ATU
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Take the output from the emitter of T1 in the 100 - 600 kHz Converter,
via a 100 nF capacitor.
Add 33 mH in series with L3 to tune down to 15 kHz.
This works well with a short antenna.
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ULTRASONIC
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Use an inexpensive 40kHz transducer to the antenna input
to detect high frequency sound from gas leaks, bearings running dry or bats -
attract them by throwing a tennis ball high into the air at dusk.
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