7372RE: [loopantennas] Loop Capacitance
- Apr 1, 2010All my loops have fed from the top and tune at the tune at the bottom as
the cap is heavy and the feed is not. The feed loop is untuned and the
line runs down the centre line of the support pole, keeping everything
symmetrical as reasonably possible although I wonder how much the feed
loop being unbalanced upsets the symmetry due to capacitive interaction.
Any thoughts on this anyone?
I think you will want to tune the capacitance of your 11m loop as it
will be tuning over ~1.2% and you can expect a Q in the 100s if the
thing is well built and if it isn't it won't work.....
For you're frequency, a simple DIY variable capacitor should be pretty
easy to conjure up as you only need 20pF or so. I have seen cute designs
using water pipe or copper sheet or PCB laminate.
From: firstname.lastname@example.org [mailto:email@example.com]
On Behalf Of ozzy_1kw
Sent: Thursday, 1 April 2010 7:12 p.m.
Subject: [loopantennas] Loop Capacitance
If the tuning is done by the small loop for best swr then for a single
band hf cb i can put the exact capacitance required or is the tuning too
sharp to cover the entire cb band??
what is the purpose for the variable capacitor ,is it multiband usage ?
PS, i see on youtube the guy that sells loops.his appear to be upside
down with the tuning capacitor on the bottom that he tunes with his
thumb. is there any issues feeding it from the top and running the coax
down the side of the loop ?
[Non-text portions of this message have been removed]
- << Previous post in topic