We’re always looking for ways to improve the reception from our radio scanners and the most obvious choice after getting a great antenna installed is to fit some kind of pre amplifier. Done correctly with the right kind of amp it can make a noticeable difference but get it wrong and you’ll end up with a whole range of annoying problems.
Choice Of Scanner Pre Amp
This has to be 90% of the battle in getting a decent receive amp fitted to your scanner and as such the choices you make when picking the equipment will make or break your expectations of what the pre amp is going to do for you.
The Underlying Problem With Wide Band Amplifiers
In general any amplifier that operates over a wide frequency is prone to dragging in some noise along with the signals you actually want to receive. This does largely depend on your local environment with more noticeable problems in built up areas or if your unlucky enough to have a strong signal source close by (phone mast, automated data transmission, pager repeater etc).
Domestic Sources Of RF Interference
Stray signals can also come from a huge amount of household items and without the amp serving them to your scanner they’d only become a problem if their on the exact frequency you want to monitor.
Some of the worst offenders when it comes to household electronics have to be televisions and computers which will happily spew out crap on some of the most used parts of the VHF/UHF bands and this can even be coming from your neighbors properties.
A better designed pre amp will go some way to reducing these problems but your not going to know how things will work out until you’ve adding the amp to your radio scanner setup.
Cost Effective Pre Amp Options
Moonraker have made some half decent pre amps over the years that go some way to cutting out the problem of adjacent signals by having a number of selectable bandwidths and this is one of the better approaches to dealing with interference.
Even though these selectable chunks of radio spectrum are broad it still gives more control over whats getting into the radio scanner.
The tighter the filter on a pre amp the less chance something is going to piggyback on the intended signal. If your interest is in a small section of the radio spectrum like the airband you could buy a pre amp designed solely for use at those frequencies.
Amplifiers will increase the noise along with the intended signal and cheaper ultra wide band models can be a nightmare. There are a range of amps made for a broad range of television use and even though they’re usually dirt cheap, should be steered well clear of for use with a radio scanner.
Reduce Interference With Masthead Pre Amps
Fitting a good receive amplifier right at the base of the your antenna is a much more expensive option than a standard pre amp but they do offer some very important advantages.
- 1. By applying amplification directly to the signal as it leaves the antenna it means the amp won’t also be “enhancing” any interference picked up on the way to the scanner.
- 2. Even with the best coax there is still some signal loss by the time it gets to the scanner. By working with the signal at source (the antenna) a masthead amplifier has much more to work with and the boosted signal loses less on the way down to the radio at the other end.
The Perfect Radio Scanner Pre Amplifier?
To stop strong, nearby signals getting into a receive amp would need some form of feedback between scanner and amp or maybe constant manual correction. Having a tight filter that could be moved to the frequency your monitoring would end problems with signal bleed over and this is how any quality wide band radio receiver deals with its own incoming signals.
This is an expensive setup but if your serious about it and considering the amount you’ve most likely already paid for radio equipment its a good starting point for the ultimate radio scanner pre amp.