"Reg Edwards" wrote in message
...

"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 )..

Sorry, should read 15 to 40 meters..... :-/

=====================================
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.

My thoughts also on both likely answers Reg but the cap is a foot long 4
inch sq 12/14kv 26 rotary vanes, now 28 as i`ve added (squeezed) two more
rotaty vanes and four stators into the frame (came in kit form), also
designed the loop using loopcalc program which gives 407pf at 3.5megs...my
cap is supposed to be 500pf !!......

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.
----
Download program MAGLOOP4 from website below to give you some ideas.

Got it, good prog......

Thanks Reg...

Lee........G6ZSG......

.................................................. .........
Regards from Reg, G4FGQ
For Free Radio Design Software go to
http://www.btinternet.com/~g4fgq.regp
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