[ELECRAFT] Using XG1 to measure feedline losses

[Ron D'Eau Claire]

Stuart K5KVH wrote:

An external 4:1 balun is typically less lossy than the built in 4:1 baluns.
Better still, use the W5YR idea, a bead ferrite choke on the coax output,
then connect there with a coax to binding post adapter for balanced line,
and you eliminate questions about your balun.

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Beads are great if you're using coax, mostly because they are low-loss and
don't change the impedance presented to the tuner. 

Sometimes a 4:1 balun is the worst choice. It reduces the impedance the
tuner 'sees' for a load. If it's being used as it was intended - in a
fairly-well matched load such as 300 ohm line to a folded dipole cut to
length - it's FB. In that case it'll translate the 300 ohms to 75 ohms, and
easy match for the tuner. 

But, if the 4:1 balun is looking into an antenna or feed line with a high
SWR the impedance it's driving might be very low, perhaps only a few ohms.
If the 4:1 balun can handle it at all, it'll divide that impedance by four
again, making it a very tough match for most tuners. 

Ron AC7AC