better antenna or antenna amplifier?

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Scottough

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I'm very new to the whole scanner and antenna world, so please bear with me if this seems like a basic question.

I'm trying to find out what would be a better option. I'm using a BCD396T scanner. I had a radio buddy tune in the police channels which are APO25 digital. I'm out in the county and trying to use a 800mhz magnetic car antenna to get a "better" signal. It's still pretty weak, so I looked into getting the GRE signal amplifier.

I'm debating whether to spend the money on a better 800 MHZ antenna or the booster.

Which would be the better value??

Thanks.
 

dksac2

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First try getting your antenna up higher and use a low loss coax such as LMR-400. If it's a car antenna, it will need to be mounted to something metal for a good ground.
An amplifier is going to amplify noise also and the antenna you are using is not the correct kind for home use.
I'd go for a better antenna made for base use, get it up high and do use the LMR-400 cable as well as "N" connectors if possible and a BNC at the scanner.
The reason for the LMR-400 is signal loss. The skinny coax you see has a great deal of signal loss at 800 MHz. Even at $1.00 a foot, the LMR cable is worth the price if you are really serious. You can also get 213 cable, just make sure to seal the connections well as it like to suck up water.

73's John
 

Scottough

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Thanks for the reply. I should have stated, that I'm using the scanner in the car. I have a magnetic mount. I appreciate the info on the cable and I'll look into a better car antenna with better coax. I did wonder if the skinny coax was good on a vehicle application or not.
Any recommendations for a good 800MHZ car antenna??

Thanks
 

K5MPH

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Let us know what mobile antenna you are using....
 

ka3jjz

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If all you're interested in hearing is 800, most any cell phone antenna is broadbanded enough to do the job.

If you want to hear other things - let us know what you want to hear...Mike
 

zz0468

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Always start with a decent antenna, and reserve a preamp for solving a specific problem.

A preamp in a mobile environment is asking for trouble. I'd avoid it at all costs, unless you're technically savvy enough to know what you're doing. Otherwise, you'll be operating a mobile intermod farm everywhere you go.

Also, be aware that many systems today are designed to NOT cover outside their political boundary. Trying to listen in to a city's system from elsewhere in the county may or may not be possible, no matter what antenna or preamp you use.
 

n5ims

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My recommendation on improving your radio's signal strength is to upgrade your antenna system in this order.

1. Improve your feed line. Using your favorite coax loss calculator, here's one if you don't already have a favorite (Coax Calculator), and find what coax will give you the lowest loss at the highest frequency you use. Compare it to what you currently use to see if you should upgrade to eliminate loss or decide what to replace your old/worn coax with. Use good quality connectors, eliminate unnecessary adapters (it's OK to have one type of connector on one end and another type on the other end if that's what's needed to do the job!), seal things up to prevent water damage.

2. Replace the antenna with one that has higher gain or is made specifically to cover the band(s) you use. A wide-band antenna will give you a large frequency range, but little distance. A band specific high-gain antenna will give you long distance but a fairly narrow frequency range. Assume that the gain is listed in dBi unless they specifically say dBd when comparing antennas. Add 2.15 dB to those that state they're in dBd to make your comparisons using a common reference point.

Be aware that they antenna makers often mislead you on what band(s) their antennas cover. If they say the antenna will transmit on 144 - 148 MHz and 420 - 450 MHz but will also work on 30 - 1,200 MHz. Read that to say it will work well on 144 - 148 MHz and 420 - 450 MHz, work rather well on frequencies near those (say 135 - 160 and 400 - 500), and work very poorly on the rest. They only say it will "work", not that it will "work well".

3. Analyze your signal levels where you listen and around the band to find those that may swamp your receiver, add noise, desense, and other issues. Add filters, move antenna, redirect feed line, etc. to correct identified problems if possible. Issues may be strong FM, TV, Paging, NOAA Weather Radio, Cell Phone, or other powerful transmitters nearby. It could also be a leaky Cable-TV cable spewing the signal out covering up your desired signals. Think of it this way, it's easy to hear someone talking softly in a quiet library and may be impossible to hear someone talking loudly in a noisy bar. You want your signals to be like that library, not competing for your scanner's detector's attention like that noisy bar.

4. Add some amplification to your signal. This should be your last resort. It can work, but it often can make things worse unless you're very careful and add filters or other devices to prevent overdriving, desense, and other issues that will cause amplification to not do what most folks think it should.
 
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