"Tim Wescott" wrote in message
...
Leon Heller wrote:
"Gregg" wrote in message
news:t4eld.149312$df2.42254@edtnps89...
I stumbled across a few at surplus outlets, I'll see if I can dig up
URL's. $50 to $150 USD, depending on KW rating.
You can build your own fairly simple though, for a lot less :-)
An old-timer I used to know made his own from plastic drain pipe. He used
a lathe for cutting a spiral grove in the pipe for the wire, and machined
most of the other parts himself.
73, Leon
I'm not sure I'd qualify anything requiring a machine lathe as being
"simple".
It is if one has a lathe. 8-)
Strictly speaking, he wasn't making roller inductors, anyway, as the contact
was moving across the turns giving one turn resolution, like a rheostat. He
only used QRP. Making a proper roller inductor for high power like those
made by Henry would be quite difficult.
73, Leon
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