On Saturday, 02 June, 2001 12:35 AM, Jon Ogden [SMTP:jono@enteract.com]
wrote:
> My wife and I have just installed some rather expensive kitchen cabinets
> that have low voltage touch lighting sensors underneath them
> It is made by Hera who I believe is from Israel.
> I've been able to get the lamp I am working with clean on all bands but
10
> meters at full legal limit. Here's what I have so far. All torroids are
> Amidon FT-77 material.
Jon, Were you getting into the lights on all bands? Or just the high HF
bands?
The RFI book suggests using #75 material for low HF and #43 material for
upper HF bands and VHF. Other info says 43 has optimum attenuation from 14
MHz to 450 Mhz with a peak near 200Mhz. While it says J or 77 is close to
75 with its peak attenuation near 6Mhz making it good for MF & Low HF
attenuation. 73 mtl attenuation seems to peak a little higher than 75 or
77/-J near 25 MHz so that might be the best to use for 10 meter problems.
> One small torroid has about 15 turns of the touch sensor wire wrapped
around
> it.
RFI book also suggest placing a 4K-ohm resistor and a 10-microH inductor in
series with the "sensing" line. I've also seen some recommendations for 3
to 4 millihenrys for the choke so try both if you can and let us know what
works!
> And no cracks about how I shouldn't have touch sensors and no religious
talk
> about how I should operate QRP.
Life's too short for QRP!
The world shouldn't have touch sensors, but they do anyway.
Thank goodness they don't generate the packets of HF noise usually created
by the free running oscillator. You'd never work any DX!
73,
de ed -K0iL
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Ed Edwards -- K0iL
PO Box 375 k0il@arrl.net
Elkhorn, NE 68022-0375 k0il@qsl.net
496-3415 home 552-5425 work 552-5505 fax
Visit my web site: http://www.qsl.net/k0il
or HDXA's web site: http://www.qsl.net/hdxa
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