Measuring Common Mode Rejection

[WA2SQQ]

I'm doing some antenna work and I'll be adding a few "chokes" to keep RF off the line. I plan on using some RG-142 cable and some 2.4" "43 Mix" ferrite. Common Mode Rejection is usually measured with a VNA, which I don't have. I'm wondering if anyone knows how / if this might be done using an antenna analyzer?

[W1AEX]

If you don't care about actual lab measurements you can get a relative indication with a simple field strength meter. That's what I do when I am mainly interested in blocking common mode RF paths back into the station. Before installing chokes, I take a reading with the field strength meter ~1" away from the common mode ingress conductor, then repeat the measurement after installing the choke(s) to get a relative indication of the reduction of RF ingress.

73,

Rob W1AEX

[W1ITT]

If you haven't already done so, you might look at the "cookbook" that K9YC worked up.  He tends to favor Mix 31.  Lots of good info, no matter what mix you go with.

http://k9yc.com/2018Cookbook.pdf

[WA2SQQ]

So mix 31 will be used for 160/75/40. Triband feed will use mix 43. Read several articles and they all seem to say more turns is not necessarily better performance. That’s why I was looking to do some measurements and experiment.