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Old February 1st 05, 01:58 PM
Highland Ham
 
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Example : To make a 4 turns loop as above you would need 2*4 equals 8

metres
of 8 lead ribbon cable using end of lead 1 and 8 as ends of the loop ,

join
ends of lead 2 and 3 , 4 and 5 , 6 and 7.


Loops made of multi conductor cables in this way tend to have a very
large capacitance between turns and in the worst case the loop will
have a self resonance frequency below the desired frequency band. Even
if the self resonance is above the desired band, the amount of
external tuning capacitance is greatly reduced.

When a wide ribbon cable is available, it can be a good idea to use
only every other lead and let the intermediate leads floating to
reduce the capacitance between turns.

Paul OH3LWR

=============================
Paul , Tnx for the above advice ,although for a loop made with flat multi
ribbon to be tuned to 60 kHz , the self-resonance freq will highly likely be
higher than 60 kHz . The ribbon I have is 15 leads wide ,hence for higher
freqs I could leave out every other lead .
Tnx again , this is good education .

Frank GM0CSZ / KN6WH