Larsen Mirage or any low profile mobile antenna any good?

Bill Rogers · Post by **Bill Rogers** » Wed Jan 21, 2004 11:08 am

Does anyone have any experience with substituting a low profile disc antenna like the Larsen Mirage for a unity gain 1/4 wave whip? Thanks, Bill.

kc7gr · Post by **kc7gr** » Wed Jan 21, 2004 12:34 pm

Bill Rogers wrote:Does anyone have any experience with substituting a low profile disc antenna like the Larsen Mirage for a unity gain 1/4 wave whip? Thanks, Bill.

I've had good results with the Antenex 'Phantom' series of LP antennas. I use one for my APRS radio, and another for my 440 radio. Both have been real troopers, performance-wise.

http://www.antenex.com for details.

Cam · Post by **Cam** » Wed Jan 21, 2004 12:41 pm

What freq?

USPSS · Post by **USPSS** » Wed Jan 21, 2004 1:17 pm

I have tested the 4" round Flat 450 Lareson, it works well in a good RF environment but in fringe area's does not perform well it showed a -9db over 1/4 wave. the Maxrad MLPV450 worked extremly well, I would say as good or better than a 1/4 wave it showed a +.275 over a 1/4 wave.. I have tested the Antenex Phantom and it performed -3db from a 1/4 wave.

All tests were with on a turntable, with the antenna mounted on the top of the vehicle, 50 watts, MACOM Orion radio. IFR 7550 and HP8753c were used for the test also.

Range is in AZ and is built for commercial RF antenna testing.

Bill Rogers · Post by **Bill Rogers** » Wed Jan 21, 2004 1:53 pm

Sorry, forgot to say UHF. Very interesting results Stan. The MLVP doesn't claim any gain! I would like to hear more results from anyone. Thanks again, Bill.

kurt meltzer · Post by **kurt meltzer** » Wed Jan 21, 2004 2:29 pm

I've used the MLPV series on UHF, 800 and 900 and agree with Stan that they work very well. I was especially impressed with the UHF model.

JohnWayne · Post by **JohnWayne** » Wed Jan 21, 2004 9:59 pm

I have been really pleased with the Antenex Phantom antennas. They come in various frequency ranges from VHF up to 2.4GHz, and are 3dB gain on UHF and above. I have yet to see one fail, so I am pretty sold. You can get better performance out of a full-size antenna, but it's not going to matter too much unless you are in the fringe.

Another low-profile antenna that I like is the Antenex Discadoo. It is similar in shape and size to a thin hockey puck. They are unity gain, however, and only come in 800, 900, or 2.4GHz.

I do sell the Maxrad and Larsen equivlents, but I prefer the Antenex. Drop me a line or give me a call if you want some more info.

Jeff Walsh
jeff@waltel.com
http://www.waltel.com
806-698-1346

Will · Post by **Will** » Thu Jan 22, 2004 2:09 am

Stan and I have done some real testing in the RF sinkhole, Los Angeles county, with his Maxrad MLPV450 and it DOES work. Car to car at 30 plus miles on UHF.

By the way Stan, I got the new dome light and installed it in my truck..."super bitche'n".

Bill Rogers · Post by **Bill Rogers** » Thu Jan 22, 2004 11:00 am

Great info! No one speakes of the flat disc type like the Larsen so I guess it isn't as good as the previously mentioned types. I should have said that a lot of the time I would be in a fringe area. Thanks, Bill.

USPSS · Post by **USPSS** » Thu Jan 22, 2004 11:07 am

Remember something about antenna's, Gain is not a power thing it is horizontal pattern compression. Most antenna manufacturers base the gain clain on an isotropic reading not a dipole reading. thus a true 5db gain antenna would require 3 segments, as a dipole refence but as an isotropic reference 2 segments make the 5db. Notice they don't say dbi or dbd in the specs. This is all marketing nothing more. The Phantom antenna cannot have gain as we refer to it in the usual sense, you must have some form of compression and ther can't be any in that salt shaker. I would love to see the reference tests on how they came to say 3db. I think some of the old guys (I guess I fit that next month at 50) will agree with this.
Base station antennas are usually rated ad dbd or with a dipole reference.

The tests I did were real world on a range in the middle nowhere against a 1/4 wave uhf antenna and the results are what I posted. Maybe Antenex missed the fact that the Phantom is -3db reference 1/4 wave and they said it is a 3db.

You also must take placement on the vehicle, the center trunk lid is about 3db down over the roof.

The other thing to take into account is where is the mobile antenna going to be used. If you are in Kansas on a flat terrain then a gain (pattern compressed) antenna will work fine and remember when you drive and the antenna bends from wind load then the pattern changes. If you are in a hilly, mountainous or diriving up a lot of valley's or hollers then a 1/4 will outperform the gain antenna since it radiation pattern is more 180 d vertical to the horizon..

Bill Rogers · Post by **Bill Rogers** » Fri Jan 23, 2004 11:50 am

Hey Stan. Thanks for the good info. Thanks everyone for the help. Bill

kf4sqb · Post by **kf4sqb** » Fri Jan 23, 2004 7:14 pm

Yeah, Stan, don't you just love the way the manufacturers use Dbi (a truely useless rating!) to rate their antennas? When I see Dbi, I usually knock 3-4 Db off the published rating. Yeah, I know, that's not really acurate, but it's probably closer than that bulls#!t Dbi rating they give you.

apco25 · Post by **apco25** » Fri Jan 23, 2004 7:57 pm

I bought the MLPV antennas based on Stan's testing and he's right they work great on UHF and 800. After I started using them I put the 1/4 and gain antennas in the backup box.

Maxrad all the way

Larsen Mirage or any low profile mobile antenna any good?

Larsen Mirage or any low profile mobile antenna any good?

Re: Larsen Mirage or any low profile mobile antenna any good