[email protected] wrote: > At 2/4/2009 21:19, you wrote: >> The Vertex has a .20uV measured and the rest of the specs are just as >> good. > > You do not need a preamp. The RX might still need an extra pass cavity, > but I'd go ahead & try it with just the duplexer if there isn't much RF in > your neighborhood. >
Another angle on this-the Vertex radios don't have much of a front end. That's how they get the extra sensitivity. A 2M repeater I used to be involved with in the 80's had a Spectrum repeater (cringe). The transmitter died (no surprise), and one of the members was able to obtain and RCA 500 series repeater pulled from service. While the Spectrum tested on the bench at abt .2uV for 20dB, and the RCA was more like .35, once installed, the RCA heard BETTER, because it had a better front end, and better a better IF/limiter chain. -another brief rant: Another BIG problem with made-for-ham FM rx's is the lack of enough gain in the limiters to put the detector in saturation, and get the benefits of FM noise rejection. I just can't say enough about a Micor or MastrII rx or a repeater.
