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Author Topic: Need Antenna Suggestions  (Read 340 times)

NZ4Z

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Need Antenna Suggestions
« on: June 12, 2022, 08:35:46 PM »

What 2m / 440 antenna do you suggest for FT-400DR mounted hood opening on RAM? Thx!
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KF4HR

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Re: Need Antenna Suggestions
« Reply #1 on: June 12, 2022, 10:46:30 PM »

Where to mount an antenna on a pickup truck, especially if the truck is kept inside a garage, can be a tricky decision.  Of course all antennas work best when they are high and in the clear, and have a nice ground plane around the mounting position, which ideally on a pickup truck would be the center of the roof of the cab.  Although getting into a garage with a roof mounted antenna is not going to happen unless the antenna is very small, or you remember to remove a larger antenna before going into the garage, or you use a motorized fold-over antenna mount such as the Comet K9000. 

If you must mount the antenna on your truck's hood I'd recommend distancing it from the A-pillar as much as possible, to minimize the distortion of the radiation pattern.  There are also mounts that bolt to the edge of the truck bed so this may be an option for your to consider too, either pocket stake mounts, or other mounts that can be attached the inner edge the truck bed.  A bit of research will turn up several options for truck bed mounts.

As far as which antenna to use.  If simplex and repeater distance is of prime importance, choose a higher gain dual band antenna.  If range is not of primary importance there are several smaller antennas that are barely visible.  On my Ram I use a small Comet B-10 antenna with a lip-mount attached on the rear door.  The Comet B-10 has little to no gain, but since it sits above my truck's cab, it gets out pretty well, plus it is still small enough to allow me to driving into my garage without damaging the antenna.  Lot's of options out there.   GL
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WB6BYU

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Re: Need Antenna Suggestions
« Reply #2 on: June 13, 2022, 06:57:46 AM »

What sort of coverage do you need?  What is your terrain like?
Where are you trying to talk to?

That all makes a difference in the choice of antenna.

I live among hills, where the repeaters may be 2000 - 7000 feet
above the valley floor.  My coverage is more mostly limited by
the terrain, rather than antenna gain.  During my commute I
could switch between two different antennas and compare them,
and found only a marginal improvement between a 1/4 wave whip
and a 5/8 wave on the roof.  So now I just use a 2m 1/4 wave
with a little coil to make it dual band, leave the radio on low power.

But the circumstances are quite different over flat ground, where
antenna height particularly is more important, and antenna gain
and power can make more of a difference.  If you're just hitting
the local repeaters, the quarter wave whip may still be sufficient.
If you're trying to cover 50 miles on simplex, then you'll likely
want something taller.

The point is, not everyone needs the same antenna.  A big, high-
gain antenna isn't always the ideal solution.  In my experience,
taller antennas with lots of joints in them are more prone to
become noisy over time, and I lost one antenna to an overhanging
tree limb.

Meanwhile, at highway speeds, some of the 5/8 wave whips can
bend over towards the back of the vehicle enough to change
the pattern and polarization significantly, since maximum
radiation is from the upper portion of the whip.  So it makes a
difference whether you are more interested in operation while in
motion or at rest.  In one case, the antenna worked noticeably
better driving down a hill than driving up the same hill, because
of the way that the antenna flexed at speed.

When I worked for the Forest Service, the only VHF antennas on
the vehicles were 1/4 wave flexible whips, because that was what
survived best among trees and also bumping along rough roads,
that can cause a lot of sway in taller antennas, especially those
with "lumps" further up the antenna.

That's not to say that higher gain antennas aren't a good choice
in some circumstances, but what is best for you will depend on
how you plan to use it.

WA9AFM

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Re: Need Antenna Suggestions
« Reply #3 on: June 13, 2022, 10:35:19 AM »

Suggest the Diamond K400 antenna mounted regardless of which antenna you pick.
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K3CXG

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Re: Need Antenna Suggestions
« Reply #4 on: June 13, 2022, 01:29:19 PM »

Check the K0BG.com website for all sorts of good info on mobile installation and operation.  Good stuff there about antennas.
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W1MOW

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Re: Need Antenna Suggestions
« Reply #5 on: June 14, 2022, 08:03:17 AM »

If you can find one...I have had good luck with the Austin Antenna 500C. It's only about 18" tall. I currently have 3 that are being used, one since 1996.

I also never understand why people don't drill holes in their roofs and then complain that their antennas don't work. I trade my vehicles in every 3-4 years and have never had a dealer say anything about the holes, especially on my F-150's, or my wifes SUV. The past couple, to make my wife happy, I have painted a metal MNO cap with matching touch up paint. If done right, it looks like it belongs there.

Gary W1MOW
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The fundamental cause of the trouble is that in the modern world the stupid are cocksure while the intelligent are full of doubt - Bertram Russell (1935)

So not much has changed in almost 90 years!

WA3SKN

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Re: Need Antenna Suggestions
« Reply #6 on: June 20, 2022, 11:28:14 AM »

What type clearance do you require?  Are you planning to use it on maximum power?

-Mike.
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