Reg Edwards wrote:
Folding is quite beneficial then at 1.9 MHz.

Not only beneficial for 160m but also acceptable for all of HF.
It's a win/not-lose situation.

How did you find what the loss actually is? Did you model it?

I modeled it using #14 copper wire and EZNEC and comparing the
maximum gain to the maximum gain of a dipole.

How far apart are the 3 wires?

EZNEC forced me to put them ~7 inches apart (minimum spacing on 160m).
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73, Cecil http://www.qsl.net/w5dxp