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using a vhf 1/4 wave antenna for dual band

Discussion in 'Mobile Radio Systems' started by WB7OXP, May 5, 2016.

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  1. WA7ARK

    WA7ARK Ham Member QRZ Page

    I have a D710 dual-band rig in my Cessna 182. Antenna is a 1/4 wave NMO on the belly, aft of the main landing gear. It works fine out to several hundred miles on 146 or 445MHz, but then a wet noodle would work from 12oooft agl.

    I couldn't use a longer whip because the tip is only 2" from the runway. If I make a hard landing, I can hear it scrape, like "gutter feelers" of yore... ;)
     
    WB7OXP likes this.
  2. VE7DQ

    VE7DQ Ham Member QRZ Page

    Mike, about one-third of the way down the whip, bend it 45 degrees (more or less) toward the tail. It won't affect the performance much, and gives more clearance for those '182' landings, of which I've had some past experience. An NMO mount and thin-wire VHF 1/4 wave is also on the belly of 'our' 172M (it's the wife's; I do the grunt work, own the hangar and get to fly it occasionally). Depending on the mission, I use an Icom A-21 (mine), A-22 (hers) or an IC-32 for VHF and UHF ham stuff.

    On my various vehicles, from time to time, I've used a VHF quarter wave antenna on UHF when I've been too lazy to change to a dual-band or UHF antenna.
    I've never been overly-concerned with vizwarz.

    Currently, I use PCTEL BMAX140/440 antennas on the daily drivers. If the OP is concerned about the length of the more common dual-band antennas, the BMAX140/440 is only 19.75" high, almost exactly the same as a 1/4 wave 2M antenna.
     
  3. WB7OXP

    WB7OXP Ham Member Volunteer Moderator QRZ Page


    first off - not concerning yourself with vizwarz is very zen sounding :)

    these guys trash, roll, and other wise brutalize their side by sides. the little sticky uppy antennas are consumed faster then fuel, they are really one of the only vulnerable components "out side" the roll structure

    being able to use cheap and robusto 1/4 waves seemed like a good solution. it also makes it easy to carry and posses spares. or even cheese one out of "bailing wire"
     
  4. WA7ARK

    WA7ARK Ham Member QRZ Page

    Already done. It seems to minimize whip vibration, too.

    on my previous '182, I had one mounted up on the fuselage, where you could see it out the rear window. Without the bend, it oscillated back and forth in the slip-stream, but with the bend in the whip, it just stayed steady...

    Today's flight
     
    KD5BVX likes this.
  5. N7WR

    N7WR Subscriber QRZ Page

    I'll go with K0BG's comments over your pompous remarks any time, any day. FWIW I have used a VHF quarter wave with great success on UHF for years. I will go with my in the field, real time performance over your alleged field experience anytime
     
    KD5BVX and WB7OXP like this.
  6. WB7OXP

    WB7OXP Ham Member Volunteer Moderator QRZ Page

    wow 124 km/hr, you must have been really flying :)
     
  7. WA7ARK

    WA7ARK Ham Member QRZ Page

    In the landing pattern at Big Springs. Practicing landings. Follow the flight backwards toward Parks, AZ, click on the red dots, and you will see some packets reporting 160mph (257kph).
     
    WB7OXP likes this.
  8. WG8Z

    WG8Z Ham Member QRZ Page

    We (and many others) run a 6" nmo whip on the race car for years (UHF).
    Only recommendation is nip the ball off if your planning on speeds over 150 mph.
     
  9. KC3ECJ

    KC3ECJ Ham Member QRZ Page

    The 1/4 wave 2 meter antenna is terrible in my area for UHF. Too many hills mountains and buildings. The signal needs to move in more directions. So on a car I use a diplexer with 1/4 for vhf and a 1/4 for UHF, two antennas.
     
    K5BBC likes this.

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