Hm, I'll have to think about that one a bit. I checked out the Elecraft
info and it appears that the balun is wound on a single binocular core,
not two separate cores. You could make a 4:1 current balun that way if
you could manage to keep the flux from one pair of windings from
coupling to the other, but I don't know right off how you'd do it. I
suspect that some sort of complex winding scheme might make it work. But
if the one you're trying to measure really has two separate cores, I
suspect that measuring the Elecraft might not be a good test of the method.

Roy Lewallen, W7EL

Danny Richardson wrote:

Yes, I measured with the leads connected together as you described.
However, after I posted my question this morning I looked around and
found I had an Elecraft BL-1 current balun. This balun can be
connected as a 1:1 or 4:1 by just moving two wires on the circuit
board - no other changes are necessary.

I measured the BL-1 in both configurations, using identical methods
which show close agreement.

You can see the results at: http://k6mhe.com/elecraft.html

Danny, K6MHE