Discussion in 'Antennas, Feedlines, Towers & Rotors' started by AE7F, Jun 18, 2015.
I don't think people ought to read antenna ads, unless they start with "Once Upon A Time..."
"It was a dark and stormy night..."
"Hope and change..."
LOL. You win.
I consider the 160 meter capability of my 43 footer, an MFJ fed through their 4:1 un-un, to be a small bonus. I think with an appropriate matching coil at the base, it could be made to work well there, and probably also on 80. My 43 footer outperforms my other two antennas for 40 meters, though, and the internal tuner on my ICOM will tune all bands from 80-6 with it. I really like it on 40-17 meters.
They do make a distinction on the specific antenna page itself that the 5KW UNUN version still needs a tuner at the operating position and 100-150ft of coax to obtain low SWR but on the verticals category page, they do not indicate that. Also considering both the length of coax and that a tuner is required really means that the antenna should be advertised as something more of a 10-60 meter antenna. Then, in the manual, it is stated that different transformers are available but one selection renders the antenna inoperable on 160m.... There is little or no modeling or electrical information posted on the main pages or in the manual.
Now, the antenna is still a good antenna, especially when modified and/or properly configured for more specific operation and it is one heck of a tough vertical antenna. Build quality is great, components and materials are great. Tom is good to work with. Definitely not bashing ZF or its products.
There is not a question about zero five build quality as it is very good. Rather it is about its operation and effectiveness vs a true resonant vertical.
I removed the 160m kit to test it. Maybe bad caps.... Anyway, I tuned up 40 and 80 how I like and here is the result at the antenna feed point:
40 meter plot:
80 meter plot:
Easy to tune, looks great installed, works well as a shortened antenna on appropriate bands.
It isn't without its compromises. According to the VK1SV calculator (http://people.physics.anu.edu.au/~dxt103/calculators/Rrad.php), efficiency on 80 meters is about 14% and efficiency on 40 meters is about 38%.
Hopefully I can get 160 working to look at some data there.
Unfortunately nobody remembers the 43 FT vertical is designed primarily as a 5/8 wave 20M antenna, with a user supplied matching network to 50 ohm coax feedline, added at the base ! (it sure is a terriffic 1/4 wave 60M ant also, but who ever heard of DXing on 60M )
A similar situation with the G5RV being optimized as a 20M antenna that just happens to "kinda work" on some other bands, with a user supplied tuner.
Try a top hat. I have a DXE 43 footer but haven't bored the mounting hole for it yet. Good platform for experimenting on.