Michael A. Terrell wrote:




It was RG62 93 ohm coax.

Certainly not in older radios. I don't know what they sell nowadays.

I've seen that 'spiral' type of cable. They basically used the spiral
as a means of maintaining the centre conductor in the average 'middle'
of the hollow dielectric.

The combined inductance and capacitance of the old cable was somewhat
critical but the older radios provided an antenna trimmer to compensate
for the variations. The electrical model was essentially a "voltage
probe" and doesn't necessarily follow common antenna/feedline rules and
thought.

-Bill