Anyone now what kind of amplifier can be used on a scanner I saw an ad in scanner world a few years back that they had them for desk tops and handheld I would like to try one on my desktop but cant find them
They are called pre-amps or preamplifiers. The are placed at the antenna to boost a signal of a particular frequency or range of frequencies. Sometimes they are used to make up for lost signal on long coax runs. In most cases they are not needed, and it would be best to spend the money on a good antenna system. If you are trying to monitor a distant system in the near microwave frequencies, such as living 50+ miles outside of a large city, and you are haveing problems, use a directional antenna and then move to a preamp if needed. Dont overlook the use of good coax as well, especially when dealing with the near microwave frequencies of some of these new digital systems being used i.e. 700mhz +.
Well, they can be anywere in line, but it is best at the far end of the coax near the antenna so that it can over come the coax loss. They make small units for handhelds but they are not of a good quality and typicaly dont work too well. If it is a good preamp it will cover a small range of frequencys such as the VHF public saftey band, no more then say 20 to 30 mhz, then the preformance starts to drop off. Check out down east microwave, just put that in google. They build great units!
Well they are band specific, as in they work best on a particular range of frequencies. Yes they do amplify everything, but that is no different then an antenna with gain. This is why its important to get an amp of good quality, and to try useing a good antenna rather then the amp first. Basicly what Jparks is saying is that along with it raiseing the signal level it will also raise the noise floor. Preamps have their place but are no substitue for a poor antenna. I use a built in preamp in my 7000 for 440 machines that are on the fringe and it works quite well. If your trying to do somthing specific let us know, if its just for general scanning it would not be a good idea.
Wow, thanks for that input. Just trying to help out a fellow hobbiest here and I dont think he cares too much about your thoughts on the subject. Try to be a little less rude next time you post and maybe add a link to some information about preamplifiers for rescue to READ. Not everyone on this site is a ham, some do not understand the basics and are just scanner listeners looking to improve the quality of their reception, give them a hand or just move on.
Thanks scott and for kb2 I have had scanners for over 20 years even had the old ones with the crystals I am just trying to get some input on amps to see if they are worth the money or just a waste of time