LF: RE: Variometer positioning

[Rik Strobbe <rik.strobbe@fys.kuleuven.be>]

Hi Chris,

 

for practical (safety) reasons I would place the remote controlled variometer at the low voltage end of the loading coil (before the loading coil, seen from the TX).

 

73, Rik  ON7YD

 

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Van: owner-rsgb_lf_group@blacksheep.org [owner-rsgb_lf_group@blacksheep.org] namens Chris Wilson [chris@chriswilson.tv]
Verzonden: donderdag 19 november 2015 13:10
Aan: rsgb_lf_group@blacksheep.org
Onderwerp: LF: Variometer positioning

19 November 2015


I am adding remote variometer control to my 136kHz loading coil. I
would like to know what impact the placement of the variometer has.
For example, I could add it before the bottom winding of the loading
coil, in the middle, by splitting the windings, or at the top, between
top winding and aerial. I am guessing I should place it before the
coil's bottom winding to minimise voltages on it, but am unsure what
other impact this may have. I am hoping to use this ex Russian device
in the link below, motor driven via its reduction gear quadrant, via a
1 RPM drive motor. It goes from about 16 to 100uH with the windings
wired in series.

Images of variometer here: http://www.chriswilson.tv/variometer.zip


Thanks.



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Best regards,
 Chris  2E0ILY                           mailto:chris@chriswilson.tv