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How much difference will the higher gain antenna make?

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Gilligan

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I currently have a UHF 450-470 MHz beam antenna; I think it has 6 elements. I would guess the gain is probably around 7-8 db. I'm considering purchasing a Maxrad 12-element beam which has 12.25 db of gain. I do a ton of searching in the 450-470 range for business-band trunked systems and can hear some towers from many miles away. I'm curious if it would be worthwhile to upgrade to the higher gain antenna or if those few db gain wouldn't really make much difference. For example, suppose I'm listening to a tower 100 miles away that has mostly garbled digital audio. Would those extra few db gain possibly make the signal intelligible? I'm also currently using a GRE preamp and am also considering a Stridesberg active multicoupler with a preamp. Thanks for any input.
 

ka3jjz

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There's a couple of factors to consider here, but probably some of the more important would be height and the clearance from any obstructions. If you were to put the antenna higher, clear of obstructions, and (here's the other side of the equation) changed your feedline (if needed to reduce loss), then maybe you might get these signals cleaner.

Remember, it's not always about gain. At UHF, you're really pushing to get 100 mile coverage. Path loss (due to the distance the signal must cover) and obstructions are going to be big issues here

Mike
 

Gilligan

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I have considered feed line and if I can get it up higher will definitely go with a low-loss type like LMR400, however right now it is mounted on a tripod on the 2nd-floor level and only has 6 feet of coax to the preamp and radio, so I don't think it's losing more than about 0.5 db. I would LOVE to get it mounted outside but am waiting until I can be sure that the grounding is proper because I don't want to get hit by lightning :)
 

ka3jjz

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There is also the possibility that the garbled digital audio is caused by a simulcast distortion issue - something to consider here...Mike
 

Gilligan

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There is also the possibility that the garbled digital audio is caused by a simulcast distortion issue - something to consider here...Mike
Definitely appreciate the input. In this particular case, I'm monitoring a number of Connect Plus towers so there is no simulcast. But that could be a reality for a county system, etc. I'm just trying to determine how much better it would be at receiving weak signals.
 
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