What is the best 2M mobile antenna?

Discussion in 'Antennas, Feedlines, Towers & Rotors' started by W5XXL, Nov 28, 2010.

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  1. K7JEM

    K7JEM Ham Member QRZ Page

    DB224E would be a good choice, if height and mounting are not an issue.

    [​IMG]

    Can't find a picture of one mounted on a vehicle, though.

    Joe
     
  2. WB2WIK

    WB2WIK Platinum Subscriber Platinum Subscriber QRZ Page

    It's a good choice for mobile work, you just need the base tilt bracket to tip it over when driving under bridges and stuff.
     
  3. K7JEM

    K7JEM Ham Member QRZ Page

    Probably will affect gas mileage.

    Just sayin'
     
  4. WB2WIK

    WB2WIK Platinum Subscriber Platinum Subscriber QRZ Page

    If well attached to the roof, it might also modify your car from a hardtop to a convertible, just by driving.:)
     
  5. KF5FEI

    KF5FEI Ham Member QRZ Page

    Is this am being it???

    http://www.hamradio.com/detail.cfm?pid=H0-003363
     
  6. K9ZMD

    K9ZMD Premium Subscriber QRZ Page

    Hamstick-style Collinear for 2 Meters

    The Lakeview Company used to market a 6 dB collinear antenna for mobile use. It was about 7' tall, and the bottom had a 3/8" X 24 stud to screw into a standard 3/8" X 24 mobile or mag mount. The Lakeview collinear is still sold, but seems to only be advertised as part of a base antenna assembly, complete with a mounting bracket and radials. See it here.

    I used a Lakeview collinear with a triple mag mount atop my Durango for the many years I helped with rally communications in SoCal. It was a great performer for simplex rally comm. I found that the collinear stayed upright well enough on freeways; however, it was definitely not advisable to keep it installed while driving to set up the back-country rally stages. I did that just one time, after which the gang dubbed my antenna "the tree killer".

    After seeing how much that collinear improved stage communication for me, one comm captain bought several of them to issue to members of his own comm crew. He also bought a bunch of those "quick disconnect" couplings so the collinear could be easily installed once stationary, and just as easily replaced by a shorter antenna before going mobile again.
     
  7. WB2WIK

    WB2WIK Platinum Subscriber Platinum Subscriber QRZ Page

    Gary, I've used those, too, as well as the Hustler CG-144 which has been on the market for about 40 years now and is still sold.

    The problem with them is the feed system is inefficient. A 3/8-24 stud has to screw into something, and that something always has inductive reactance at 144 MHz. The ground point is too far from the base of the antenna, always, no matter what kind of mount you use, for such a high frequency.

    The NMO is a vastly superior design because it's actually good up to about 1 GHz or so without any reactance. The ground is right next to, and very close to, the center conductor so the connection leads can be kept extremely short and not add inductance.

    When I was VHF Editor for CQ magazine, I ran tests on a flat beach at the Jersey shore (flat as a pancake, no local obstructions, buildings, hills or anything else -- it's a near perfect antenna range) for close to two weeks and many participants tried everything, including the Lakeview, the Hustler collinear, stuff from Antenna Specialists, Cushcraft, Hy-Gain, Kreco, just everything, and we weighed them against my simple Larsen NMO-150 in a through hole mount in the center of the roof of my station wagon.

    We did this with six repeaters about 90 miles away each, in all different directions, and we drove in a continuous circle during all the tests (we made a "track" on the sand about 100m in diameter, and just continuously drove around the circle, to help smooth out the effects of antenna mounting location), and in real-time, transmitting within a few seconds of each other, we got continuous quieting reports from the repeaters. We calibrated our output powers to be 25W plus or minus less than a Watt, using the same meter to measure all the transmitters. My Larsen 5/8 wave whip beat everything else, consistently.

    I was actually surprised about that, since some of the antennas were 2-3 feet longer and had claimed substantially greater gain. But it just didn't show up, ever, on six repeaters that were way over the horizon in all cases.

    One of the repeaters we used was 147.06 in Philadelphia, which had a SINAD reporting system that would actually tell you how strong you were every time you keyed up. A hundred times in a row, the Larsen beat everything on that.

    During one of the many circle jerk tests, I found I could key up the 146.91 repeater on Mt. Greylock, MA, which was 188 miles away. So, we all QSYd to that frequency and all tried it. I was consistently the only one who could actually talk to someone through that repeater, while the others tried but couldn't quite connect.

    This was a very telling test; not just about the antennas themselves, but their mounting, grounding and installation variables. Some of the guys were using mag mounts, including 3 and 4 magnet designs. Some were using the big 7 foot collinears. Some used homebrew designs they felt positive would outperform everything. Nothing did.

    This was in 1986, but not much has changed since then. I wrote an article about the test, with photographs, etc.

    I've used the Larsen NMO-150 5/8-wave 2m whips ever since, and still use them. But of course, it's not just the whip, it's also how and where it's installed. Through hole NMO mount, center of roof, wins.:)
     
  8. KG4ZAR

    KG4ZAR Ham Member QRZ Page

    OOPS!!! Wrong inputs!!!
     
    Last edited: Nov 30, 2010
  9. K9STH

    K9STH Platinum Subscriber Volunteer Moderator Platinum Subscriber QRZ Page

    Back in 1971 Hustler/Newtronics made 3 copies of a prototype mobile antenna that fit on an NMO mount. That particular antenna worked even better than the Larsen NMO-150. It was slightly over 5 feet long. Unfortunately, that antenna never went into production. When I was the first FM Editor of CQ Magazine they sent one of the 3 prototypes to me to try. Although I did not have a real antenna range, I would work stations on FM simplex and drive out until the Larsen was not really working. Then I would remove the Larsen and put on the Hustler. On average, from the mobile I could always drive at least another 30 miles, and sometimes more, before even getting "scratchy". The terrain was varied from relatively flat land to some pretty good hills.

    One evening I started out from the north side of Dallas, Texas, was working a station on the south side of Fort Worth. The Larsen gave out at Howe, Texas, which is about 45 miles north of Dallas. I changed antennas and kept on driving north. I was about 20 miles into Oklahoma before the signal from the station on the south side of Fort Worth even started getting any noise at all. So, I turned around and came back home.

    Newtronics, for some reason, had not really documented how the antenna was manufactured. Of the 3 prototypes one was lost in the mail and the 2nd one that they had kept was destroyed trying to get the coils out of the "potting material" that was used to encapsulate them. So, they asked me to send back the one that was sent to me. I did send it back. But, after that I heard absolutely nothing about the antenna. The version that they introduced a few months later looked nothing like the prototype that had been sent to me. This "new" version also performed no where near as good as the prototype. I have no idea as to whether or not they were even able to dissect the one that I used or if actually producing that particular antenna was way too costly. But, I have never discovered a mobile 2-meter antenna that worked as well as the prototype Newtronics/Hustler.

    Glen, K9STH
     
  10. WA4OTD

    WA4OTD Ham Member QRZ Page

    I remember you talking about this antenna before and glad it came up again. I would like to try one of these at the next opportunity. The height of this will be whacking into stuff like my 40M hamstick!

    What about the Larsen dual band (2M/70CM)?

     
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