Need some help with my 5BTV

Discussion in 'Antennas, Feedlines, Towers & Rotors' started by N4FMG, Apr 9, 2012.

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  1. N4FMG

    N4FMG Ham Member QRZ Page

    I finally got my vertical up, Hustler 5BTV, the antenna is obove my shop with a metal roof, Roof dimensions are 32X31 feet.
    I wasn't sure what dimension chart to use for the assembly from DX engineering, so I Used the mounted on roof with radials.
    but there are dimensions also for tower with radials, ground no radials, ground with radials.

    I used the prefered radial for metal roof instuctions with 16 radials draped over the metal roof.
    I didn't connect the antenna gnd feed point to the roof ( wasn't sure if I was supposed to )

    Is there any best method for this installation on a metal roof?
    Any idea what dimension chart I should use?
    I was thinking about reseting it to the ground mount with radial settings as my radials are not tuned length just random length.

    Also the radials are all the same length with some of them hanging off the edge of the roof.
    I was able to get 10m to tune but 15 is way off it's lowest swr is 2.0 at 19.8-- mhz, Have a antenna analyzer to tune with (MFJ 259b) the other 20 and 40 are about the same and 80 I
    have a dip at 1.4 swr at 3.7815
    Not sure what I'm doing wrong here or what I should change on the setup.
  2. WB2WIK

    WB2WIK Premium Subscriber QRZ Page

    I think DX Engineering has done a great job of making a very simple antenna complicated.

    The "old time" Hustler instructions for a 5BTV (liek 40 years ago) was: Put it up, add radials, adjust the tubing lengths for minimum SWR on the frequencies of choice," and that was pretty much it. They worked great, simply following those instructions.

    You tune up each band from 10m to 80m, one by one, starting with 10m. The tubing lengths all adjust a lot in length just loosening the clamps and re-tightening them. Sounds like you're way off on 15m because the tubing between the 10m and 15m traps is set too long. Change that. 80m is usually the "last" adjustment you'd make, after everything else is done, and is adjusted by the whip length above the loading coil.

    It's a really simple antenna.
  3. N4FMG

    N4FMG Ham Member QRZ Page

    Any ideas on the ground plane, Should I just leave the radials I have draped on the metal roof, I dont have a connection from the antenna base and the
    metal roof at them moment.
    And will the length of the radials be important?

    There was one other thing, When I'm adj for resonance should I move the trap cover up or down or adj the gap between the trap and sleeve?
  4. KH6AQ

    KH6AQ Ham Member QRZ Page

    I would attach the 5BTV coaxial cable shield to the metal roof. If you do use radials use two 1/4 wavelength radials per band; not all the same length.

    You will need to tune the antenna band by band starting with 10 meters. If you are unable to obtain a good enough match (1.5:1 or lower) you might have to tune a trap or two. DX Engineering has directions on how to do this. An antenna analyzer such as you have is needed. Mark the trap with a permanent marking pen so you can reset it if needed. I've tuned the traps for a ground mounted installation and it's not difficult.
  5. W9GB

    W9GB Ham Member QRZ Page


    If this is a new BTV antenna, them Leave the trap covers ALONE !!
    ADJUST the spacing between traps, as outlined in instructions.
    DO NOT cut tubing.

    Plenty of damaged BTV antennas on used market due to pilot errors.
  6. WB2WIK

    WB2WIK Premium Subscriber QRZ Page

    I must agree with this. In the "real" Hustler instructions they never advise to adjust the traps in any way.

    DX Engineering's instructions do. I've never had to. The traps are sealed from the inside and the moment to move the trap upper cover to adjust one, you break that seal (and Hustler stipulates this also voids the warranty). I wouldn't bother with that.

    The tubing lengths (NOT traps!! -- just the sliding aluminum tubing sections that make up the radiating element) are all adjustable, bottom to top.
  7. N4FMG

    N4FMG Ham Member QRZ Page

    Got up on the roof last night and reset the antenna to the settings recomended from DX Eng. They recomended using the
    ground mount with radials for my base settings. Also did some more work in the radials laind out over the metal roof and added a way
    to connect the metal roof to the feed point of the antenna base so I can try it both ways

    It got dark out before I could tune it so that will be tonights venture

    Thanks to all for the tuning info, the DX eng. insturctions are a little unclear and confusing as to what section (the trap cover or the tube below it.) to adj for your tuning.
    I'll keep everyone posted.
  8. WB2WIK

    WB2WIK Premium Subscriber QRZ Page

    There's nothing the slightest bit confusing about the original Hustler instructions.

    If you look at this short instruction guide, dimensions "A" adjust 10m; dimensions "B" adjust 15m; dimensions "C" adjust 20m, and dimension "D" adjusts 40m. They must be adjusted in that order:

    None of that has anything to do with trap covers. They specifically advise:

    That's printed in bold lettering in the Hustler instructions.

    DX Engineering went on to create a 60-page "BTV" manual (!) which IMO is about 58 pages more than needed. It's a really simple antenna and there's not much to it, or to adjust. I'd never adjust the trap covers.
  9. KO6WB

    KO6WB Premium Subscriber QRZ Page

    You will find the radials you have will couple to the metal roof. It's sort of like you had it ground mounted with a bunch of radials. Tuning the radials is good but not necessary. The 5BTV will still work well.
    Use the instructions from Hustler and you should do well.
    Have fun
  10. N4FMG

    N4FMG Ham Member QRZ Page

    Ok got on the roof last night after resetting the antenna to the specs for ground mounted with radials.
    16 radials laid out over the roof and the metal roof attached at the ground feed point.
    tried it with out the radials attached and the band dip points dropped further down the bands.

    All the bands are tuning low in the band the best I can get 10m is 28.600 for its cener point.
    15 will dip around 20.700 at 1.9 swr , 20 meter dip is in the lower part of the band 1.6-1.7 swr , 40 meter is out of band on the dip as well. 80 m looks o.k it's 3.783 at the dip point at 1.3 swr.
    the gap at the 10m adj is complely closed and I cannot shorten the antenna any further,

    Not really sure where to go at this point. Should I add more radials and try for tuned lengths?
    I know the bands above 10m adj point will all be off till I get 10m sorted and can go up the antenna from there.
    15m bothers me because the lowest swr I see even out of band is 1.9 to 2.0 swr.

    I'd move to the ground and but I dont have any clear area that dosen't have metal around it, all closer than 20 feet from any mounting
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