I am announcing my support for Choke Baluns! Lots of folks say they don't matter much. I disagree based upon my own research here at the KI4FH labs! With a Coax Choke at the feed point both my 40 Meter dipole and 20 Meter Dipole, both flat-tops, are pleasantly broad banded and offer a low SWR. Without the choke, there was resonance to a degree but the antennas were not as broad banded.
So I have played around with several iterations of center feed insulators. All homebrew using Sched 40 PVC. I have also hidden a #73 Bead Choke Balun inside a PVC tube but the weight is too much for the occasional torrential summertime Florida storm. I now incorporate a waterproof taped piece of Coax with 50 #73 torrid beads on the cable. This is working out excellently although it is ugly. To lower stress point issues on my 8X center conductor and braid, I have them fed into a straight through PVC cap to an SO-239.
I prefer the bead balun when the number of turns of cable to effect the same result would cause a lot of weight at the center. On the 20 meter antenna, the turns are about 6 with a 4 1/2" air core The cable is strapped together with UV resistant ties. This works great.
To round things out, I purchased a Budwig Center Insulator from WizeSupplize and am now experimenting with that as opposed to one of my waterproof home brew centers.
It seems pretty tight!
So, that is it for now.
73, KI4FH
SK
