Are these antennas any good?

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acurayyz

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I'm looking for a minimally-invasive solution for using my scanner in the car. I came across these window mount antennas which claim to work for 30-1200mhz. My main use of the scanner in the car is airband (108-136) and Bell Fleetnet (up around 141-146 iirc). Do you think this type of antenna would be useful if mounted behind the rearview on the windshield?

Scanner Antenna Uniden Motorola radio BNC glass mount | eBay
 

WouffHong

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Doubt it

I'm looking for a minimally-invasive solution for using my scanner in the car. I came across these window mount antennas which claim to work for 30-1200mhz. My main use of the scanner in the car is airband (108-136) and Bell Fleetnet (up around 141-146 iirc). Do you think this type of antenna would be useful if mounted behind the rearview on the windshield?

Scanner Antenna Uniden Motorola radio BNC glass mount | eBay

As a 60-year Ham, and retired GTE and NASA RF and Antenna Eng'r, I seriously doubt it will do anything good below 400MHz, if that, based on it's assumed size. The 30 MHz claim is laughable and sets a credibility baseline. But, Caveat Emptor! ;-) :roll: :roll:

Da Wouff..
 

kayn1n32008

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I highly recommend a NMO 5/8 or NMO 1/4 wave on an magmount cut to resonate at about 120Mhz, it will have no problem with air and Fleetnet. If you use a Vhf 1/4wave it also resonates on Uhf as well. If all you listen to is Vhf go with the 5/8wave. Go with the KISS method and stay away from all the 'wide'or 'broadband' band antennae.
 

krokus

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If you really want an on-glass option, look at the Larsen product line. My on-glass 2m antenna worked reasonably well, even with a well sub-par setup.
 

W2NJS

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The claimed specs for that antenna are pure baloney. Physically the unit shown might be a UHF loaded dipole, and it might also work on 800 mHz, but I guarantee you it will be poor to plain lousy on VHF and 30-50 mHz lowband if indeed you can hear anything at all on both those bands. And if I were to install this unit I'd be sure to orient the elements vertically, otherwise there goes another 3 to 6 db down the drain.
 

WA1ATA

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A minimally invasive antenna suitable for VHF airband is Workman Scan4 Scanner Antenna SC1 The exposed section of the coax is about 19" long, which is about right for 150MHz. To optimize VHF airband reception, I'd strip off a few more inches of the braid.

Or simply take a few feet of coax and strip off the last 25" of shield. Since the coax is just a few feet long, the higher loss but smaller coaxial cables are suitable. If you have any BNC to BNC jumper cables around, you already have what you need to homebrew this antenna.

Obviously, this will not work as well as an outside mounted antenna, but I have frequently used this sort of antenna is rental cars and the improvement over the scanner-mounted rubber duck antenna is very significant.
 
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