[AMPS] E F Johnson Roller

[Rich Measures]

>
>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.
>
€  Amen.  And the short should contain minimal R.  


Rich...

R. L. Measures, 805-386-3734, AG6K, www.vcnet.com/measures  


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