feed line length for an antron 99 as a counterpoise

[k4get]

I have an Antron 99 what is the proper length of rg213u or lmr400 for a counterpoise ? I've heard 50ft. but not sure if this is correct.
I do have a ground plane kit coming soon.
I guess iam looking for the best length of coaxial for best swr and resonance.
thank you for any help.

 

[mmckenna]

Counterpoises are usually 1/4 wavelength or greater. So you'd want at least 9 feet. More won't hurt. But the ground plane kit is a much better approach.

As for "best length of coax", the best length is whatever length you need to get from the antenna to the radio. No more, no less. Any talk about specific lengths of coax necessary are pure fiction perpetuated by CB'ers.
You can use specific lengths of cable to "hide" mismatched antennas, but that's all it does, hide the issue, not fix anything. A properly installed and tuned antenna will not require specific coax lengths.
The rumors of specific lengths of cables never take into the account the different velocity of propagation of individual types of coax cable.

 

[TheSpaceMann]

You can duplicate the ground plane kit using wire!

 

[W5lz]

There is no 'proper' length of coax for a counterpoise for an A-99. There is a minimum length though, and that's probably around 8 - 10 feet. That length is typically at least what it takes to get from the antenna to the radio so it's a sort of an "ain't no thang" thing. If a metal pole is used for it's support, it's part of the 'counterpoise' too. And since that A-99 is tuneable, you tune for the best you can get. See?