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Rich: Created page with 'Antenna comparison http://www.interceptradio.com/files/wiki/antennas.jpg 20 antennas were tested to see which ones were the best for receiving. All the antennas are 3/4" Mo…'

2010-01-06T02:19:42Z

Created page with 'Antenna comparison http://www.interceptradio.com/files/wiki/antennas.jpg 20 antennas were tested to see which ones were the best for receiving. All the antennas are 3/4" Mo…'

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Antenna comparison

http://www.interceptradio.com/files/wiki/antennas.jpg

20 antennas were tested to see which ones were the best for receiving.

All the antennas are 3/4" Motorola TAD/TAE mount (aka "NMO").

The following lists are ordered as per what you see in the picture (left to right).

General information:

Manufacturer Model Type Freq rating/gain
------------------- ------------------ ---------------------------------------------- -------------------------
Larsen NMO-27 (new style) 1/4 wave base loaded 27-28/0dB
Radiall/Larsen NMO-27B 1/4 wave base loaded 27-28/0dB
Larsen NMO-30B 1/4 wave base loaded 30-40/0dB
Larsen NMO-50C 1/4 wave base loaded 47-54/0dB
Larsen NMO-2/70 (old style) loaded 1/2 (VHF), closed coil collinear (UHF) 144-148/6dB 440-450/3.5dB
Larsen NMO-150 (new sytle) 5/8 wave base loaded 144-148/3dB
Larsen NMO-Q 1/4 wave 150-170/0dB
Larsen NMO-Q 1/4 wave 95-105/0dB
Antenna Specialists ASPRD1615 1/4 wave 430-470/0dB
Maxrad BMUF9000 1/4 wave 896-940/0dB
Larsen NMO-450 5/8 over 1/2 wave closed coil collinear 450-470/3.4dB
Motorola TDE6082A (?) closed coil collinear 460-470/5dB
Larsen NMO-UHF 5/8 over 1/4 wave open coil collinear 450-470/3.2dB
Maxrad BMUF8125 1/2 over 1/2 over 1/4 wave open coil trilinear 806-866/5dB
Maxrad BMUF9043 1/2 over 1/4 wave open coil collinear elevated 896-940/3dB
Larsen NMO-800 5/8 over 1/2 wave closed coil collinear 806-866/3.4dB
Maxrad unknown 5/8 over 1/2 wave open coil collinear 806-866/3.4dB
Larsen NMO3E825B 5/8 over 1/4 wave closed coil collinear 825-896/3.2dB
Larsen NMO5E825B 5/8 over 5/8 over 1/4 wave closed coil trilinear 825-896/5dB
Maxrad BMAXSCAN1000 double 1/2 over 1/4 closed coil collinear (800) VHF/UHF/800

Performance:

Model LW AM SW CB VHF-Lo FM Air VHF-150 VHF-165 VHF-TV 220 MilAir UHF-Lo UHF-Hi UHF-TV 800 900
-------------------- -- -- -- -- ------ -- --- ------- ------- ------ --- ------ ------ ------ ------ --- ---
NMO-27 (new style) 2 5 5 7 2 2 - - - 2 1 - 2 - 2 6 4
NMO-27B - 1 4 7 5 4 4 2 3 4 4 1 2 1 5 4 4
NMO-30B - 1 4 7 5 4 2 1 2 4 5 - 2 1 5 1 3
NMO-50C - 1 2 2 7 5 3 7 6 5 3 - 1 - 3 2 4
NMO-2/70 (old sytle) - - 1 - 2 4 3 6 7 6 5 2 8 8 5 3 4
NMO-150 (new sytle) 2 6 5 4 5 5 4 7 5 5 5 - 2 2 1 1 1
NMO-Q (150-170) 1 4 3 2 2 4 5 4 8 6 5 3 5 4 5 4 4
NMO-Q (95-105) 1 5 5 2 4 6 5 3 5 5 2 1 4 2 5 3 5
ASPRD1615 - 2 3 - 1 3 1 1 2 4 2 1 7 6 4 5 5
BMUF9000 - 1 1 - 1 1 - 1 1 3 1 - 1 1 4 7 6
NMO-450 2 5 5 3 4 6 5 2 6 5 2 2 6 5 4 5 6
TDE6082A (?) 2 6 5 3 5 6 4 2 4 5 5 1 5 4 3 2 5
NMO-UHF 2 5 5 2 4 6 4 2 5 5 2 1 6 5 4 5 6
BMUF8125 - 6 5 2 5 6 5 3 5 5 5 1 2 - 4 6 7
BMUF9043 1 7 5 3 2 5 6 5 6 6 5 2 2 1 5 7 7
NMO-800 1 6 5 4 3 5 5 4 8 6 6 3 4 3 6 8 8
Maxrad (800) - 3 2 3 2 5 4 3 6 6 5 1 2 2 5 6 4
NMO3E825B - 5 5 2 1 5 3 2 6 6 5 2 3 2 6 6 4
NMO5E825B 1 6 5 3 3 6 5 3 5 5 2 2 1 1 3 6 4
BMAXSCAN1000 - 3 5 2 2 5 5 4 6 6 5 1 7 6 6 4 5

- = Absolutely no reception
1 = Extremely bad reception, you might barely receive some very strong stations.
2 = Bad reception, strong stations come in very weak but can be heard.
3 = Limited range reception, stations come in about 1/4 - 1/2 the strength compared to an average antenna for this band.
4 = Below average reception, stations come in about 3/4 the strength compared to an average antenna for this band.
5 = Average reception. Stations come in at reasonable levels.
6 = Slightly above average reception, perhaps 1/2 to 1 S-Unit above an average antenna.
7 = Above average reception, perhaps 1 to 1.5 S-Units above an average antenna.
8 = Great reception, perhaps 2 S-Units above an average antenna.
9 = Too good to be true.

All tests were done with an AOR-3000 receiver.
Minimum of 5 measurements per band from fixed stations at varying distances and power levels.

Comments:

Yes, I know the NMO-30B has the wrong whip in the picture. I tested it with the correct whip.

The MilAir readings are somewhat pessimistic since all I had were a handful of
weak stations to test against. It wouldn't be unreasonable to knock the numbers
up a few notches to estimate how it would perform in general operation.

The lower-frequency base-loaded antennas tend to block out VHF/UHF, most likely
because of impedance issues where the coax couples to the loading coil. Its
interesting to note how the 3rd-generation Larsen NMO-27B has partial VHF reception
while the 2nd-generation NMO-27 does not. My guess is that Larsen made an engineering
change to accomodate CB radios like the Cobra-29WX which include a VHF weather-band
receiver. Another interesting thing to note is the 800mhz reception. While I certainly
wouldn't count on a low-band antenna for 800mhz, whats likely happening is the loading
coil itself is acting as the receiving antenna given the short wavelength of the signal.

The Larsen dual-bander (NMO-2/70) is totally deaf below VHF. Probably another loading
coil impedance issue since it will have a base-load to correctly match the half-wave
VHF radiator.

The Larsen NMO-150 works great for VHF, shortwave and AM but chokes on UHF and 800.

The quarter-waves and other antennas lacking a base-load (800mhz collinears, etc) all
seem to work great at lower frequencies, since there are no impedance issues with
loading coil coupling. Likewise the lower freqs see it as a chunk of wire, minus some
miscellaneous impedances when it hits the coils on the antenna rod. The only exceptions
to this rule are the UHF and 800/900mhz quarter-waves where the antenna is physically
too short to have any receive efficiency on the lower frequencies.

As per the above note, the open-coil Larsen NMO-UHF turned out to be a real
winner. While slightly less performing on 800/900 since its not designed for
it, this would be a great selection for an "all-band" antenna to connect to
a wideband receiver like an AOR or a Yupiteru.

Now for the curve-ball. Look at the Larsen NMO-800. Given its short size I kind
of scratched my head at the lower-frequency performance, but the tests don't lie.
Nonetheless I probably wouldn't count on it compared to the much longer NMO-UHF
for broadband reception, but if very small size was a requirement this would definitely
be my second choice for a compact antenna. Notice the performance difference compared
to the Maxrad 800 which is of identical size and electrical design, with the only
difference being an open coil compared to a closed coil. Even the most minor differences
can make a large impact on performance.

So.. my first choice for a compact antenna would be the Maxrad BMAXSCAN1000, since
it has much better UHF performance than the NMO-800, and reasonable performance
on the other bands.

I had hoped to see the Maxrad elevated 800mhz trilinear be the winner since it
had the combination of long physical length, high 800mhz gain, and no base-load,
however it ended up being so-so on VHF and pretty crappy on UHF. Still not bad in
the overall scheme of things.

The big Motorola 5db UHF did surprisingly well on the lower bands, but the
thing is just too darn ugly to put on my car.

The Larsen 3E825 was one of their Nextel OEM's. The 5E825 was on a Larsen "Special"
base. The 5E825 was pretty awesome when it came to broadband operation, except it
was somewhat deaf on UHF which was sort of a party-pooper.

Now its brand-preference opinion time !!

First, always use NMO mounts. They are THE standard and give you the most
options for swapping antennas around on your car. You can also use them
for base antennas, just use a mobile L-bracket and screw it onto your mast
or whatever. Get some copper rod at the hardware store and attach 3 or 4 ground
radials to the mast (unless receiving only 800/900mhz with an antenna
designed not to require a ground).

Larsen and Maxrad are the way to go. On some models you can save a few bucks
and still retain quality with the Maxrad.

Don't use mag-mounts unless you really have to. I don't care what the manufacturer
says, they will scratch your paint. Not to mention they don't ground as good as
other mounting arrangements.

Drilling holes in your roof is the best way to go (performance-wise), but personally
I don't like turning my cars into Swiss-cheese. Go with L-Brackets on the hood
or rear deck, as it takes two minor side-drilled holes that won't be an issue
when you sell your car. Edge-mounting antennas like this will give a ground only
halfway around the base of the antenna which can make for less-than-optimal radiation
patterns, although I certainly haven't noticed any problems worth crying over.

Another great mount is the trunk-lip bracket. The Larsen ones are ugly and expensive.
Get the Maxrad. These require no holes and work great. Sometimes you need to do
minor antenna re-tuning on lower-frequency antennas since part of the radiated
signal will bounce off the metal on the roof of the car. Again, not a perfect
radiation pattern but certainly usable.

If you plan on receiving 800/900mhz using an NMO mount, check any cable that
you got with your antenna or bracket and see if its standard RG-58. If so, chuck
it and get an 800/900mhz NMO mounting kit that has RG-58 double-shield or better
cable (Cushcraft Ultralink for example). Despite the loss-per-hundred-feet ratings
on RG-58, you can suffer noticeable losses if you use it on short mobile cable runs.

Remember to pick up the twist-on "rain caps" for your antenna mounts and drop them
in your glove box. They cost like $1.50 each and come in handy if you need to stash
your antennas in the trunk when you park your car downtown, at long-term airport
parking, or in one of the less friendly neighborhoods.

Glass mounts suck for a variety of reasons. Single-band receive on 800mhz is about
the only worthwhile use for these terrible things. Make sure you don't have aftermarket
window tint and make sure your glass doesn't have carbon-impregnated tint. Best way
to tell is to look at the glass from an angle under bright sunlight with polarized
sunglasses and look for oval "splotches" in the glass. If you have this kind
of glass, the best way to get around it is to use a service monitor with on-glass
coupling boxes connected to the tracking generator and spectrum analyzer, then
hunt across the glass until you find a hot-spot that passes the signal good.

2-19-2003 Rich W7KI

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Mobile Antenna Comparison - Revision history

Atomic taco: Wikification

Rich: Created page with 'Antenna comparison http://www.interceptradio.com/files/wiki/antennas.jpg 20 antennas were tested to see which ones were the best for receiving. All the antennas are 3/4" Mo…'