Unless a small reduction of RF energy fixed the problem, for example lowering
the voltage just under a semiconductor threshold, hardly those 6 turns works
like an effective choke at 7 Mhz.
Only chance is when parasitic capacitance of the coil skyrokets reactance
because resonance of the coil goes very close to the used frequency. In such a
case the coil made of cable acts as a trap, beeing this the method to choke
efficiently at a voltage node.
More probably you fixed the problem altering the cable lenght, or by collapsing
the line in the coil, or by legnhtening the coax for adding the 6 turns choke.
73 & HNY
Mauri I4JMY
>
> It depends on what you are using the balun for. I found 6 turns to be
> effective on 40m. in the shack between transmitter and ant changeover relay.
> I had an rf feedback problem on that band, that wouldn't go away no matter
> what (copper ribbon ground strap, 1/4L ground radials under the floor, rf
> chokes, bypass caps, etc). The 6-turn balun cured the problem immediately.
>
> Don K4KYV
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