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MFJ-1976 10 foot telescoping whip RV ladder mounted

Discussion in 'RV Operating and Camping' started by K6EEN, Dec 4, 2021.

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  1. K6EEN

    K6EEN Ham Member QRZ Page

    Here's an SWR chart of the MFJ-1976 telescoping whip from a RigExpert AA-650 Zoom analyzer, with a 2 ft coax jumper between the feed point and the analyzer (i.e. no long coax in the measurement). The antenna is mounted on a 3/8x24 trucker's mirror mount on the rear ladder of the camper. There's a 1 inch braided ground strap running from the antenna mount to a frame bolt on the rear of the RV. Seems to do a good job resonating on 12 meters and 11 meters. I bring it down to 1:1 with a MFJ portable tuner near the radio.

    MFJ-1977 SWR chart RV mounted.png 20211106_130948.jpeg
     
    Last edited: Dec 4, 2021
    KG4RRH likes this.
  2. KG4RRH

    KG4RRH Premium Subscriber QRZ Page

    I've got an MFJ-1979 (17ft) that I've been thinking about trying the same thing on. I've used it before on 10m by adjusting sections are out.

    Unfortunately, our RV is still in the factory:(
     
  3. K6EEN

    K6EEN Ham Member QRZ Page

    I've tried the 15 meter band MFJ-1977 which is 12 ft long. The antenna separated at the bottom two sections after only extending it twice. The shorter ones seem slightly more hardy (12 meter and 10 meter band, 10 ft and 8 ft models MFJ-1976 and MFJ-1974) because of less stress at the joints due to less overall length and weight. I'm waffling on trying the 20 meter version (MFJ-1979) as after my experience with the 12 foot 15 meter band model, I think a 17 footer wouldn't last more than a few hours!

    The on-line reviews for the MFJ-1979 seem to shift around the year 2017 from "great antenna" to "falls apart easily". My guess is MFJ switched their supplier around that time and went with cheaper manufacture & materials. The older pictures show a brass base to these whips, the newer ones look like stainless steel bases, not brass.
     
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  4. KK4OBI

    KK4OBI Ham Member QRZ Page

    I have three MFJ-1979 telescoping whips for my RV. Why three when you only need one?
    First, 10 metes was working way back when so all I needed was a vertical around 8 ft 3 in. and a single wire radial taped to the roof and adjusted in length to get the lowest SWR. (Trying to use the ladder or RV frame for ground plane just did not work). Turns out this one radial lash-up is directional so I put the wire on a bamboo pole so I could aim the radial towards where I wanted the most signal.

    Next, sun spot activity dribbled out so 20 meters became the only game in town. Now I needed a 17 ft. vertical... MFJ-1979 to the rescue. But the bamboo pole support for the radial left a lot to be desired... another MFJ-1979 to the rescue. But, darn it, two 17 ft elements are too short so I added wire extensions to get the antenna to tune around 14.2 MHz. Then one of the telescoping sections quit telescoping. Got tired of using tape to hold it in position so I bought a third MFJ-1979 as a replacement.

    Just before the Covid situation developed I got gave up on ever working 17 or 15 meters and decided on only 20 meters. I replaced the MFJ-1979 radial with a 20 meter Hamstick. This is more compact, eliminates the wire extensions and is considerably easier to tune. Modeling shows the difference between the long and short radial is too small to hear.

    That's my story and I'm sticking to it. Maybe there is an idea in there for you
     
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