> I have an idea of resonating my existing vertical on 8 kHz.
> Is there a practical way to construct a 600 mH loading coil, withstanding
> 3-4 A and high voltage? Any *large* toroids on the market?'
> /Christer
> sm6pxj
Are we locked into HF thinking here? Why not use an iron cored
inductor such as the output transformer from a QRO valve audio
amplifier?
Mike, G3XDV
Although an output transformer might be fine for a matching
transformer it would not be suitable for a loading coil because of
the high voltage across it. It might be more practical to use several
coils in series with the lowest one being a variometer.
On 136kHz I now use a variometer and coil designed for 500kHz with
the additional inductance mounted in a weather proof enclosure
outside the shack.
On 73kHz I use the variometer and 136kHz loading inductance inside
the shack with an additional inductance outside the shack, thereby
spreading the voltage gradiant over this three-stage booster.
On 8 kHz this could be taken the necessary stages further.
Whichever way you play it you will need a lot of wire!
While on the subject of 73kHz I hope to be on tomorrow at the bottom
of the band before 1000UTC
Regards, Peter, G3LDO
<[email protected]>
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