How To Add 17 Meters and the "Ugly Balun" 
to a Fence Mounted Hy-Gain 18AVT Vertical Antenna
by N6JSX/8, MS-EET 02/2012

I bought this used Hy-gain 18AVT 5-band (80/40/20/15/10m) vertical in the mid 80's. I mounted it 12" off the ground in California, it sort of worked but I was NOT impressed with few DX contacts. Now with +40yrs of HAM'ing, all the internet articles, and QSO's that continue to tout HF verticals being the theoretical best antenna for DX it was time to resurrect my moth-ball from the rafters.

Here is what I did to restore my 18AVT, making it one of my NEW FAVORITE HF antennas at my Ohio country home.

First, I refurbished the antenna making all joints shine, again. Applied liberal amounts of Penetrox to all joints, replaced all clamps with stainless steel clamps, made new top hat radials (using copper coated steel brazing rods - bird strong), cleaned up the 80m coil and re-hot glued it back together. I replaced the old stinger cut for 3925 with a new stinger cut/tuned for 3800 (what a hassle that was to buy from MFJ/Hy-gain).

I course adjusted all traps to cover "my" SSB selected centers; 28,500, 21,275, 14,220, 7,180, & 3,800. Mounted and retuned all traps starting at 10m working down to get a 1:1 on all selected centers using a MFJ-269. It's a lot of up-down work (why I use wing nuts on the U mounts) but worth the time. I use nylon guy rope for added stability due to serious open county Ohio winds.)

I dislike ground radials due to all the required work to install properly; so here is where I was going to experiment. I mounted the AVT to the fence post of our new chain-link fence.

{ Recently we installed a fenced area behind our house-garage to allow our Jack Russell Terrorists free but controlled roaming then installed doggy doors to the area. One of my better home improvements that "bought" me favorable accolades from my XYL! }

The 5' chain-link fence is mounted at 4' height (burying one foot into the ground for anti-dog dig-out). The near house section is 18' long (up to the side gate) where the AVT is mounted as seen in the photo below.

18AVT and "balun" mounted on chain link fence

I've read about the attributes of the Ugly-Balun, here was my opportunity to test it.

http://www.hamuniverse.com/balun.html

My Ugly balun is made on 4" PVC with 26 wraps of RG-8x (~30' of wrap), used hot glue at the holes and electrical tape on the ends - easy. Bent up some mounts and attached itto the fence - high enough to insure the lawn tractor misses it too. The fence has anadded bonus of providing a nice off ground coax run to the house.

The Ugly-Balun really made my vertical a performer. I now got into EU, Med, Africa, and Asia (as well as all points North America). This vertical NOW impressed me and was living up to vertical DX claims. Using my IC-746P and MFJ-989c I was making solid DX contacts even during flaky band conditions. I only need to use the tuner for 75m outside 3725-3875 and the extreme edges of 40m SSB due to >2.5:1 swr. The recheck of my 18ATV center frequencies showed all to be 1:1.But I was still not happy with the 18AVT as it isonly five-bands (80/40/20/15/10m), myfavorite day time band is 17m.

More........See the entire article and read how I added the balun and 17 meters to the Hy-Gain 18AVT! PDF file download. Enjoy! N6JSX

Also see an updated refurbishing project on the same antenna here!

Editors note: The 17 meter modification and the Ugly "Balun" can be used on many verticals including all of the Hustler 'BTV' series and many other verticals. Have fun and remember to have an antenna party, not a funeral when working near power lines!