Hustler 4BTV

[KC8CAY]

I have a 40 foot tower that I just erected. We placed the 4BTV at the top but I have 2 questions hopefully someone can answer...
1) Do we still need to put radials at the bottom of the tower?
2) I can't get this antenna to tune on 40m and the best I can do on the other bands is 3.0/1. Does anyone know of any numbers for the distances between the traps that could get me in the ballpark? The numbers the factory gave me in the manual are way off.

thanks again!

KC8CAY/Ben

 

[W5LZ]

Actually, those numbers the manual gives you are very close. Alittle adjusting from them if normal. The key word in that is 'little'.
While a good ground system at the bottom of a tower is always a good idea. Unless the tower becomes part of an antenna, that ground system is a safety ground. That antenna you have would bebefit from having a 'ground' at the base of the antenna, not the base of the tower. A top set of guys would be very handy in that regard...
- 'Doc

 

[RickC.]

Hey Ben,

In that installation for the antenna to operate properly you'd need to have it insulated from the tower either multiband radials or separate ones for each band (except 40/15).

Can you give more details about how it's configured?


Rick

 

[KC8CAY]

Sure, I have been scolded already for putting a vertical atop the tower. So everyone says that I need ground radials. My next question is if I bring the antenna down and mount it against the side of the tower and run ground radials, will the tower affect the performance?

Ben

 

[Robb]

Yes; it will interact with the tower.

These particular antennas require ground radials as a counterpoise to keep the antenna operating as designed. This should also keep the SWR where you need to see them too.

Doc's idea of running radials at the base of the antenna at a downward slope may work. But you will need at least two for each band, and the will need to be cut to 1/4 wave in length for each band. All you need to do is measure and cut enough guy wires and attach them with enough guy rope to keep them insulated at some point below. The ANGLE of these radials MIGHT be a problem for getting the SWR correct.

Just $.02 . . .

 

[W5LZ]

If you have three guys at the top of the tower, and can make them at least close to 1/4 wave on 40 meters, they will also act as a counterpoise for the other bands. Do it well? No, but they'll at least 'work'. On second thought, forget about a 1/4 wave on 40 meters, they'd probably be long enough, and even 'too long' is better than none at all. Just attach them to an anchor at ground level as you normally would.
That would mean doing some more tuning on that antenna to compensate for the 'too long' radials. It still should do better than what you've got now anyway.
- 'Doc

 

[RickC.]

I would expect that to be a very effective antenna elevated at 40', especially on the higher bands-- with it insulated from the tower and with resonant radials (even one per band would work though it would not be optimal), but having it grounded to the tower is playing havoc with your tuning, and adding radials on the ground (which is what I think you mean) isn't likely to help that much.

From your callsign, I take it you're a relatively new ham-- congratulations! We've all been there.

Have you read this-- the DX Engineering Hustler High Performance Installation Instructions?

DX Engineering - Antennas, Antenna Systems and High Quality Antenna Components! Look on the 4BTV page, at the bottom.

Peruse the installation guide w/r/t elevated mounting. Do you happen to have an antenna analyzer?


Rick