At 03:39 AM 7/11/05, [EMAIL PROTECTED] wrote: >As far as what has changed....the new piece of equipment(repeater) is >by the specs more then twice as sensitive but on the bench it tested >more like 3 times as sensitive as the old repeater. We are going up >today to try some more testing and I will get back to this thread >with the results.
Spec sensitivity is like a paper repeater. Anybody can write whatever they want. Bench sensitivity is with no noise or other signals - the receiver is operating in the best of all possible worlds. "Real world" sensitivity (normally called Effective Sensitivity) is what really counts. See Chris Boone's writeup at <http://www.repeater-builder.com/tech-info/effectivesens.html> If you still have access to the old repeater it would be interesting to see an effective sensitivity number on it, then drop the new repeater into the EXACT same lashup - the same duplexer-to repeater jumpers, the same everything. More below. Nate Duehr WY0X <[EMAIL PROTECTED]> > >> Our local club has been running a 10 Yausu 2410 2 meter > >> repeater for many years. It is run through a Wacom wp-641 4 can > >> duplexer. Great results from this unit and it hears excellent....We > >> recently aquired a new vertex vxr-7000 do to some really nice friends > >> locally. In hooking up the new machine we have terrible desense on > >> lower signals that would still be full quieting into our old machine. Please describe the entire system - is there a preamp? Is there an isolator/circulator, any cavities other than what is part of the duplexer, what type of antenna, etc. > >First off, just in case of a common mistake: If you replaced the cables > >going to the duplexer and didn't replace them with good quality > >double-shielded cable... stop and go do that right now. RG-142 or RG-400 are two possibilities. 142 has a steel core and can fracture if bent too much, 400 is preferred. See <http://www.repeater-builder.com/rbtip/double-shielded-coax.html> Mike 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/
