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Author Topic: best ant for parked mobile?  (Read 569 times)
KB1CIW
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Posts: 3




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« on: August 31, 2002, 09:36:20 AM »

What is the best mobile whip antenna for parked mobile use ? The big Bugcatcher at around 13 ft should work better than a hamstick on 20 and lower,but a 17 foot whip using a tuner as close as possible might be event better.Is there a company that makes  a long whip ? I would not be driving while using this antenna but would like to be able to mag mount it when parked.
tnx
Bob, KB1CIW
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K0BG
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« Reply #1 on: August 31, 2002, 09:40:22 PM »

Look up my call on this site to see a picture of my 13.5 foot mobile antenna.

Texas Bug Catcher makes all sorts of 80, 40, 20 meter coils in 3, 4 and 6 inch diameters, and a variety of different lengths of masts. Others do too, but I have not had any problems with anything I purchased from them. As for the whip, what you see in the picture is a standard Radio Shack 102" whip which cost all of $10.

TBC makes an 8 foot mast, and along with an 8 foot whip,  spring and mount will resonant on 20 with out a coil.

The old adage is, the longer the better.

Alan, KØBG
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WB2WIK
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« Reply #2 on: September 03, 2002, 07:31:55 PM »

But the post said "mag mount it."  I'm not sure I'd use a mag mount for a very large HF mobile antenna...sounds like scratches & dents just waiting to happen.

If the intention is to always use this antenna when parked and absolutely never use it when moving, an off-vehicle antenna might be best; that is, an antenna located near the car, but not on it, with the feedline coming through a door, vent or window.

I installed a 40 meter 1/2-wave inverted vee in a 40' tall tree in a park near the beach here, more than five years ago.  It's fed by about 75' of RG8X coax, which is normally coiled up and hung from a lower branch at about 7' above ground.  It's still there, or was last time I checked a few weeks ago.  Since it's nearly invisible, even the local kids never bothered it.

When I want to go "parked mobile" in that area, I drive into the parking lot and find a space near that tree, unroll the coax and plug it into my mobile rig.  I've won many a "mobile shootout" this way.  No matter what anybody has mounted on their car, truck or RV, when they pull up near me and use it, I always clobber them on 40 meters with my 66' long inverted vee at 40' as a "mobile" antenna.  Another benefit of this antenna is that it cost about $5 to build.

Something like this might be worth considering.

WB2WIK/6
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KB1CIW
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« Reply #3 on: September 03, 2002, 10:53:21 PM »

Tnx guys,
Well I guess I should have said "best *Quick, *easy, *mag mount, mobile antenna" I live in an area of a city where it is best to keep antennas in the trunk until it's time to use them.I already have a ladder line fed dipole and a 33 ft telescoping fiberglass mast. This works great on the rare occasions when I have time to drive down a dirt road in a *real park. I'm more likely to be operating in a parking lot or by the side of a small city basketball,playground park. Some times I drive up to the top of a hill(CT) where there is a small parking lot and picnic-ers,young lovers and dogwalkers strolling about. I also do lunch break radio. One 30 minute lunch break = 5 minutes to use the facilities +10 minutes to eat +3 minutes to set up the antenna +10 minutes to operate, +2 minutes to take the antenna down. What I'm really looking for is a lightweight 16 foot fiberglass/whip antenna in 4 4 foot sections.
Nott makes a 22 foot telescoping whip intended to be used with their screwdriver antenna. I think it can be used by itself but I imagine a 22 foot telescoping whip must be a bit fragile and easily bent when dropped.

I'm told that one of the 20 meter county hunters used to make a custom built big sectional antenna for county hunters but I don't have any more information than that.

I'm considering modifying the coil on a hamstick base and screwing a 102 " CB whip into it. That might give a 13 + foot antenna with helical winding for 20 meters.
   Another possibility would be the 13 foot Outbacker,but I think it's  rather expensive for an antenna that is just a tapped coil and whip.
   I know the maker of the "minuteman portable antenna and he said he could make me a 3/8 mounted version of it for parked mobile so I'm considering that also.
tnx & 73
Bob KB1CIW
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AB8JC
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« Reply #4 on: September 05, 2002, 04:41:49 PM »

How about some of the military screw-together whips?  You can get them up to 16' really easily, and a guy here at work has one that'll go up to 32' IIRC.  Just might need an adapter to go to 3/8-24 thread.  A tuner would be needed, of course....  Check our www.fairradio.com

Steve AB8JC
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KE4SKY
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« Reply #5 on: September 24, 2002, 02:45:48 PM »

I carry 55 foot (for 75m) and 32 foot (for 40m) lengths of AWG14 gage wire, each with a crimped and soldered 3/8" ring lug on one end, bolted to a Hamstick quick disconnect.  The other end of each wire has a "dog bone," insulator, 50 feet or so of 150-lb. test nylon construction twine and a 2 ounce surf casting sinker.  The whole thing is wound around a cheap Walmart extension cord storage reel.

When I want to operate HF mobile for public service events I simply throw the weight up about 25-30 feet up into the nearest tree, tie it off, then remove my regular Hamstick and attach the QD on the wire of choice to the vehicle ball mount and drive forward enough to stretch out the antenna out as a sloper.  

You may have to fool with the length of wire to get a good match for your vehicle on your working frequency. On my Jeep Cherokee, a full sized pickup or an RV the end-fed quarter-wave wires load up fine on 40 or 75 meter phone bands without a tuner, but with a compact car you may need to stake out and attach a few  counterpoise wires to the vehicle.  Using the internal tuner on my FT900 I can work the whole band.

It isn't as efficient as a full-sized wire dipole which is resonant on your working frequency.  It is better for "short path" NVIS operation than typical vertical mobile whips because it is horizontally polarized.  Its a full S-unit better than a hamstick dipole on 40 or 75 meters and it's a cheap and easy field expedient antenna you can teach your RACES operators to set up and use which doesn't take a whole crew to erect!


73 de KE4SKY
Virginia RACES State Training Officer
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KB1CIW
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« Reply #6 on: September 27, 2002, 08:47:38 AM »

tnx KE4SKY
Unfortunately most of my operating occurs in treeless parking lots for less than 30 minutes at a time, so I really need a whip. I've ordered a "Park 'n' Talk Whip" made by Not Limited and sold through Antennex.com. I'll let you know about it when the box  comes.
73 Bob KB1CIW

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KE4SKY
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« Reply #7 on: September 27, 2002, 09:06:45 AM »

Another viable option for parked mobile in a treeless parking lot, which gives better results than a vertical whip on short paths is the hamstick dipole.

If you would like the handout which we distribute at our RACES training sessions just send me an email and I'd be pleased to send the Word document.
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