I had a caliper and Johnson model 226-1 handy. The ribbon coil is .125 x
.250 silver plated copper. This model has 5 turns wide spaced and the
remainder close spaced. Johnson made other models besides this one.
I was asked at one time why an amp using a roller coil arced. If unused
turns are not shorted out a transformer is created. Depending on where
the coil is tapped the open end can develope a rather large voltage (rf)
and really play havoc inside an amp. ALWAYS SHORT OUT UNUSED TURNS OF A
TANK COIL, whether a roller or switched circuit.
Many roller coils by numerous manufacturers are made differently. I have
about 4 differnet types of large roller coils, most use ribbon and
several use wire (round). BTW, NOT FOR SALE. Will be using several.
73 de Arne N7KA
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