Dear Group: I expect to craft a common-mode choke for 50 ohm coax that
works from 1.8 to at least 7 MHz using Type 31 (Fair-Rite) core material.
Use of any Fe material in coax at the lower HF frequencies is undesired - no
center conductors containing steel. Such coax should be able to tolerate
being bent with a small radius to facilitate multiple turns through the
core - no foam dielectric.

One such coax appears to be the expensive RG-400. Only need a few feet.

Question: What might be a source for short lengths of RG-400? I have tried
Newark, Mouser, and the like. . . .

Question: What other small diameter coax uses no steel and has a solid
dielectric?

Thanks. 73, Mac N8TT

J. C. Mc Laughlin
Michigan U.S.A.
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