"Lee" wrote in message
. uk...
Hi!....
I`ve just built a magloop 5`square and i find the variable cap only
tunes
down to 4.45mhz..
can i pad the cap out with a coaxial ur213 stub to reach 3.5mhz
???....
Lee.......G6ZSG.....
(The 1metre loop works fine - 15 to 7mhz ).. :-)
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Lee,
You will need at least 70 percent more capacitance.
But where you'll find that much, high voltage, high Q capacitance is
anybody's guess. You would do better to fit a larger variable
capacitor designed for the job. Or make a larger loop.
A lumped capacitor made from coax cable is low Q anyway because of the
small diameter of the inner conductor. Compare coax inner conductor
diameter with loop conductor diameter.
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Download program MAGLOOP4 from website below to give you some ideas.
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Regards from Reg, G4FGQ
For Free Radio Design Software go to
http://www.btinternet.com/~g4fgq.regp
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