Since becoming active in April 89, the majority of my antennas have been mostly indoor.
My first outdoor antenna was a Cushcraft R-7000 which, while much better than anything I had used to that point, was somewhat limited in getting out.
With the prodding of my buddy Carl, I ordered a replacement, the Hy Gain AV 18HT Hy Tower.
This antenna has a long track record and many are in use today both as stand alone multi band antennas, and also in phased arrays.
Getting the antenna erected was a simple matter, thanks to the excellent instructions. Not the ones that came with the
antenna, but from the excellent website of Carl Strode – WA7CS, it is so good in fact, MFJ has a link on there site
for those seeking information on the antenna.
I have now got the unit assembled and wait only to finish up the radial system and other items necessary to insure proper operation.
My observations to date are as follows.
First, I learned early on that MFJ tech support is very eager to serve, however as far as this antenna, they seemed
to be lacking in any understanding of how the unit worked.
When asked on several inquires about the specs on some part of the system, I was never able to get any real answers to the questions, and was simply informed that there are many of these in service and users love them.
Not much help in learning why the unit is capable of only 20% of rated power on one band.
My best source of information, both on installation & theory came from two hams.
Carl Strode - WA7CS, has a site covering the
installation.
His site is so good that Hy Gain had a link to it on
there own site.
The second Randy Crews W7TJ did a review at E Ham Net, and covered the theory of operation including instructions for making the coil used for 160 M coverage.
Both are must read if you plan to use the antenna, the information is better than anything your likely to find at company site.
If you opt to install the 160 meter base loading coil, Randy's review gives the instructions for winding this simple coil.
The savings of approximately $109.95 for that coil can be used to purchase the parts necessary to finish the antenna ( realistic ground radial setup, replacement locking collars of stainless steel in place of the shall hunks of flattened emt tubing that you run a screw into for adjusting the whips on two of the elements.)
Two other items of interest, are a static choke and some form of lightning protection.
The static bleeder choke is a simple 100 turns of wire wound on a 2” dia. PVC pipe and connected from the antenna to the ground plate. Hopefully this also will serve for any lightning that might visit the antenna.
I chose to run my ground / radials on this system from a substrate that was independent of the legs running into the base, in the event of a direct strike I am not sure of the effect that might have on the concrete so I opted to use a radial plate made of copper strapping soldered at the corners. I also mounted an SO239 to the same strapping for ease of connecting the coax.
If anyone has thoughts on this contrary to mine, I would like to hear from you.