Mathew, The choice is usually between bipolar and GaAsfet, and depends primarily upon the noise level at your repeater site. Sometimes, reception can be improved more by using a higher-gain antenna and/or a lower-loss feedline, than by adding a preamp. In any case, the best results are achieved by adding a sharply-tuned bandpass cavity filter between the duplexer and the preamp. Otherwise, the preamp will amplify a lot of noise along with the desired signal, and is very vulnerable to overload.
An excellent tutorial on preamps is at: <http://www.anglelinear.com/repeaters/repeaters.html> 73, Eric Lemmon WB6FLY w9mwq wrote: > What type of preamps are available for VHF to enhance the receive of a repeater? I know, if you can get by without it, it's better off, but this is only a temporary attempt, to see if it makes an improvement for the system for the winter. Also, if anyone has a good deal on one, let me know off list on that as well. Thanks for the input. BTW, thanks to all who have offered support this far; the repeater is coming along just fine and is working quite well. > > Mathew > W9MWQ > > > Yahoo! Groups Links > > > > Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
