On Mar 9, 2010, at 8:37 PM, [email protected] wrote: > t most certainly does. Try random length cables from the cavities to the > T instead of 1/4 wavelength (like one local did several years ago) & watch > your sensitivity drop by over 20 dB if you're unlucky (as he was). That > mistake literally killed off a local radio club, as few of the members were > able to use the repeater following the addition of the T & wrong cables.
Thanks both Bob and Skipp for explaining that one odd-ball configuration that would crush the receivers with random cable lengths that just happen to hit the right "sweet spot" to do this. I suspect, that if someone saw a 20 dB loss while installing this setup, they'd at least STOP and start asking questions -- maybe they wouldn't "get it" that they'd hit this "perfect storm" combination -- maybe they'd think they had some kind of receiver failure when it suddenly was "really deaf" -- but I also doubt that *most* people would hit the problem. Would you agree with that assessment? (Skipp's comment that if there's a train wreck to be found, he'll be there... I know that feeling.) I guess what I'm saying here in a round-about way is... random cable lengths really shouldn't be that much of an issue in a setup like this, but yeah... agreed... once in a while it'll bite you like an alligator (had to get that elephant/alligator theme in here, just one more time! GRIN!)... I've seen lots of people get away with it. As far as the 3dB lost in a true broadband splitter -- also true, of course, Bob -- at most of the sites where we have to share a receive antenna with multiple rigs, the site measured noise-floor is so high the 3dB doesn't have much of an impact... just keeping the local crud out of the receivers is difficult enough -- sometimes that 3dB loss helps, instead of hinders, so to speak. :-) I guess we should all probably also mention the evils of not terminating all the unused ports on a multi-splitter with 50 Ohm loads, too... if we're going to get this picky, right? ;-) -- Nate Duehr, WY0X [email protected] facebook.com/denverpilot twitter.com/denverpilot
