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Scanner / Receiver Antennas For discussion of any type of receiving antenna used by a scanner or receiver base, mobile or handheld.

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Old 09-07-2012, 11:42 PM
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Default Phantom antenna

How good are the phantom antennas for the vhf 137-174mHz. Reception, power, ect....


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Last edited by dixie729; 09-07-2012 at 11:47 PM..
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Old 09-08-2012, 2:30 AM
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You can only miniaturize an antenna 'so much' before performance suffers. Squishing something like 19 inches (typical 2 meter 1/4 wave length) into 2 - 4 inches only works if you are dealing with fairly strong signals. They tend to be for a sort of 'stealthy' mobile antenna. They are the equivalent of a mobile version of a 'rubberduck'. If you are close to the transmitting station, no really 'big' obstructions between you, it'd probably work okay.
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Old 09-08-2012, 9:49 AM
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If your application involves transmitting, be sure to check the usable bandwidth of this type antenna from the manufacturer's specifications. In my experience a typical usable bandwidth for such a VHF antenna is only about 1 mHz. UHF and 800 mHz designs of the same type may have a wider bandwidth.
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Old 09-08-2012, 10:40 AM
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I bought a few Laird/Antennex VHF versions and they are noticeably worse than a 1/4 wave whip on the same mount. They are also very narrow band and I tuned one for 147MHz and its about 2:1 match at 146 and 148MHz and really bad on some 144 and 145MHz freqs I use.
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Old 09-08-2012, 10:57 AM
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The only useable application that I have found for them is as the antenna for a vehicular cross band repeater and only because we had them lying around unused already.

We use them with midland and GE Exec II low band radios that include the VHF mobile extender and since the coverage range needed was less than 1 mile we found that the 300 milliwatts output of the VHF mobile extender with the phantom antenna on a single frequency works fine but for anything else forget it.

For anything else I found that less than 15 watts with no more than a 750 KHz bandwidth was all they could handle.
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Old 09-08-2012, 3:29 PM
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It will be used on 154-155

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Old 09-08-2012, 3:36 PM
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The frequency won't make much of a difference to how well it works. You either buy them with a tuning adjustment on the side, or you buy them pre-tuned.
I've never used one because EVERYONE I know that has used one has been disappointed. There are very specific cases where they would make sense to try one. I've heard they make a bit more sense up around 800MHz, but they are still a "compromise" antenna. The installations where I have seen them used is usually on someones vehicle that is more concerned with the looks rather than performance.
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Old 09-09-2012, 2:05 PM
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The reason they work better on 800MHz is because a quarter wave is only 3 inches which would make them a quarter wave whip inside a "radome". On VHF they'd be essentially a rubber duck in there and you know what we call rubber ducks... dummy loads.

More concerned with looks than performance? That bump on the roof looks like something that doesn't belong there. (;->)
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Old 09-09-2012, 8:17 PM
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They suck.. Use a 1/4 wave ..If you get the black one it is hardly noticable
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