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Old April 3rd 08, 11:30 PM posted to rec.radio.amateur.antenna
Wimpie[_2_] Wimpie[_2_] is offline
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First recorded activity by RadioBanter: Mar 2008
Posts: 329
Default through glass coax coupling

On 3 abr, 23:42, Haines Brown wrote:
Wimpie writes:
Why not using inductive coupling? You can get reasonable coupling as
wires are just mm away from eachother, so you don't need high Q factor
circuit.


Didn't occur to me. Are you suggesting a couple coils sharing an axis,
one just inside the window and the other outside? Would the two coils
simply be designed for a 50-ohm impedance at, say, 10 meters?

I can imagine wrapping a 50-ohm coil on pvc, and inserting it into a
larger diameter pvc that is capped and which has a coax connector passing
through it. and the whole attached to the glass with silicone
adhesive. One on either side of the glass.

Matching indoor only is possible (so you don't need matching outside
to interface to 50 Ohm coaxial cable).


Not sure of your point. It seems I need to match outside.

Another problem just occurred to me. I'll use a MFJ magnetic loop, and
its tuner, if I recall, depends on an uninterrupted electical connection
through the coax. If so, I'm stuck.
--

Haines Brown, KB1GRM


Hello,

I was thinking of just 1 turn windings glued on the window of about
D=10'' (correctly aligned), in combination with a two trimmer
capacitor match (from which one can probably be a fixed value after
experimenting).

When you would do matching both inside and outside you can get a
broader response. Window glass is just about 0.15'' thick, so I think
a single match (inside) would have sufficient bandwidth (especially
when you would use foil/strip material for the two single turn
windings).

Best regards,

Wim
PA3DJS
www.tetech.nl
please remove abc from the address.