How to increase the range of a radio scanner

Radio Scanning has come a long way since the old ‘Rock Boxes’ of the 1970’s. This article explores how to get the best performance out of your analog or digital radio scanner.

The way scanning used to be

The way scanning used to be

Radio scanning is a great hobby. Not only do you stay informed with happening in your neighborhood or community, but listening to a radio scanner can keep you safe in times of severe weather, natural disasters, civil unrest, or even large community events. But to make scanner listening effective, you need a strong signal for the receiver, especially if you live in a rural or fringe area.

By this year, just about every public safety radio system has made the transition over to the 7.5 Khz narrowband channel spacing. Narrowband channel spacing allows the FCC to put more radio signals into a given range of frequencies. But the narrowband comes as a tradeoff. Since the radio signal takes up less spectrum, it also becomes weaker and harder to receive. Narrow band signals already sound quiet on older wide-band scanners, so compounding things with a weaker signal to start really doesn’t make for a good scanner listening experience.

Here are three tips that will help you continue to receive a top quality signal for your radio scanner.

1. Use an external antenna

The stock antennas that come with your handheld and base scanners are considered compromise antennas. They are designed for portability and to receive the widest range of radio signals. An antenna that can receive anything sounds like a great idea; who wouldn’t want just one antenna to pick up every signal under the sun. But this compromise delivers mediocrity: meaning it can receive everything, but does a lousy job doing it.

KB9VBR 2 meter J-Pole antenna

If you analyze your listening habits, you’ll find that you may spend the majority of your time listening to either the 136-174 MHz VHF high band or the 430 – 470 MHz UHF low band. Most communities, especially smaller and more rural ones tend to congregate all their signals in either of those bands. (If you live in a large urban metro, your public safety frequencies have probably already migrated to the 800MHz band. But that story will be saved for a later post). An antenna that specializes on either of those bands, such as the 155-160 MHz Land Mobile and Scanner J-Pole antenna or the 462 MHz GMRS and Land Mobile antennas are excellent choices for reception on either of those bands. The J-Pole antenna has a low noise floor and wide bandwidth, so it will do an excellent job picking up your VHF and UHF signals.

This external antenna needs to be mounted outdoors to really be effective. Best places to mount the antenna would be on your roof, like at the peak or on the chimney. Radio Shack and most home improvement stores sell TV antenna mounting kits that work great for this purpose. Other locations that work would be a mast of 10 or 20 feet planted in the ground or attached to a fence post. If these locations aren’t suitable, (maybe you live in an antenna restricted community), then putting the antenna in the attic would be a good solution.

2. Consider a signal amplifier

scanner amplifier boosterAfter you’ve got your antenna mounted outside you should expect to receive radio signals from at least 20-30 miles away, maybe even further if the public safety agency is using a high powered repeater system. But what if the your desired signal still comes in weak? A signal amplifier may be good solution. Amplifiers are made for a wide variety of signal ranges or uses, you’ll want to select one that is designed for 50 Ohm radio systems, and not one designed for a 75 Ohm cable television system. Watson makes a good, high quality amplifier.

One caveat of signal amplifiers is that they will also amplify noise and static. They will also cause very strong signals to bleed and overload the receiver front end of your scanner. If you are planning to use an amplifier to boost your signal, make sure you also pair it with a high quality antenna and scanner.

3. Change out your feedline coax

One of the biggest detriments to receiving high quality signals with your scanner is to use inexpensive coax feedline. High quality feedline can get the pricey, so the general attitude is to get by with the cheapest possible. But the type of feedline you use can make a big difference to the quality of signal received. How do you know what type of feedline to use? First measure the length of your feedline rune, to determine the amount of coax you will need to go from the scanner to the antenna mounted outside. Next consider what frequencies will you be listening to; are they primarily VHF or UHF. Finally consult this handy chart to determine which type of coax will be best for your situation

I recently wrote an article about feedline types and their loss characteristics. Using the correct type of feedline makes a very big difference in the quality of the signal you’ll receive. It doesn’t do your radio system any good to use an externally mounted antenna and boost the signal with an amplifier to only lose all those gains in the feedline.

With these three simple steps, you’ll be on your way greatly improving the quality and range of your scanner signals. Good luck and happy scanning.