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Old 06-05-2011, 12:42 AM
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Question Amp

looking to boost my receiving trying to get a community 25 miles away . and it sounds all hissie on my live feed
I'm using Uniden BEARCAT BC 760XLT
on a Radio Shack Mode 20-176 antenna mounted on a 10 foot mast on my roof approx 30ft from ground

I have a Electroline EDA 2100 LINK below to Spec sheet could this be used as a amp to get a better signal i know nothing of how the amps work just a shot in the dark any ideas or suggestions

http://www.electroline.com/en/produc...fact_sheet.pdf
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Old 06-05-2011, 9:57 AM
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Quote:
Originally Posted by NBPTFF8 View Post
i know nothing of how the amps work just a shot in the dark any ideas or suggestions
The ability of your system to receive a signal depends primarily upon the signal level into the first active stage and the noise figure of the first active stage. By first active stage I mean the first RF amp in your scanner, or if you add a preamp, the preamplifier.

Where preamps make a lot of sense is when there are high losses in the coax between the antenna and your scanner.

Coax losses are much higher at 800MHz than at 155MHz. Coax losses in RG58 is much higher than the relatively cheap RG6 quad shield

By locating the preamp up at the antenna itself, the full signal received by the antenna goes into the preamp. The preamp then amplifies the signal from the antenna enough to compensate for the coax loss so that the additional noise from the scanner front end is small. Locating the preamp next to your scanner doesn't help. The preamp specs you linked to show a 3dB noise figure. That isn't really all that good and is probably worse than the preamp in your scanner, so adding the preamp down next to the scanner would probably make your reception worse.

Do you have a line of sight to the tower that you are trying to receive? If not, then raising your antenna will probably make much more of an improvement than a preamp.

==================================

There are lots of knowledgeable people here on RR. To get the best advice it would be helpful to tell us:

1. What frequency? (exact not needed. Just 800 vs. 460MHz vs. 155MHz...)

2. What type of coax and approximate length?
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Old 06-05-2011, 10:02 AM
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Newburyport Fire and Police

NBPT Fire 158.955 PL 203.5 NBPT Police 483.012 PL 146.2
roughly 60 ft coax 50 and a 10 50 Foot of RG-58 coax cable

defiantly not a direct line of site cant go higher ahole neighbors

Last edited by NBPTFF8; 06-05-2011 at 10:24 AM..
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Old 06-05-2011, 1:39 PM
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Welcome to Times Microwave | Coaxial Cable - Attenuation & Power Handling Calculator is a handy calculator of coax cable loss.

60' of RG58 at 482 MHz will have a loss of about 6.2db; and at 158MHz about 3.5dB. Going to RG6 would reduce the 482MHz loss to 3.7dB, an improvement of 2.5dB.

The 6dB loss at 482MHz is pretty significant and that much improvement would probably eliminate most of the hiss. If you have a way of powering up your scanner while at the base of your mast, you can pretty much see how much improvement you are likely to see by just taking your scanner up on the roof and connecting to the antenna using just the 10' length of RG58.

Whether or not the preamp you are looking at is the best choice is something I don't have the experience to comment on.
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