Well you gave the problem in the 1st couple of lines
1) USE Double shielded coax between duplexer and repeater...throw out
the RG 8 foam stuff...NEVER use RG 8 in a rptr install...
2) Hamtronics....enough said
3) Ringo Ranger antenna...if it's loose in any place, it will cause
problems....need to get a real repeater antenna....One without a ring
that depends on a cheap ring connection for matching.

Depending on the cleaness of the RF output, and how good is the rcvr in
overload conditions is what determines the isolation you need in the
duplexer....95db isolation is easy to find...WACOM WP641s, 642, and
other makes!! Get your isolation better than 80db and get rid of the
crap coax...and you'll be a lot better off!

Chris
WB5ITT at arrl . net

me wrote:

Hi guys. Thanks in advance for any help. Please post
responses in NG as my email 'reply' address is fake
since some don't know how to mind their manners.
I recently put back into service a Hamtronics REP100
two meter repeater with a new Telewave Duplexer and
the antenna is a Ringo Ranger II with radials. Coax to
the antenna is RG8 superfoam and jumpers between
repeater and duplexer are RG8 superfoam.
Here is the problem. I am experiencing 'desense' on
the repeater to the point where it takes a signal of S5
or better to get in. A lesser signal just makes the
repeater "chop" (continually opens and closes the
transmit side. The Duplexer was factory tuned
(for what it was worth) and I did 'tweak' it and got a
much noticible improvement. Before tweaking, it took
an S9 or better to get in. I realize I should be running
(supposedly) double shielded jumpers from repeater to
the Duplexer, but I can't imagine they are going to make
that much difference. I am also told to mount the duplexer
in it's own enclosure (it's rack mount so that would be cute)
to keep it away from the repeater.
The Hamtronics manual says you HAVE to use a
duplexer with at least 95 db of isolation (try to find one)
and mine is 77db. I really can't imagine there is not
enough isolation, because I know where there are other
machines running with old duplexers with much less
than 77db of isolation. Just to add to the mix, I sent
the repeater up to Hamtronics and had it tuned and
checked out and it is 100 percent, so I *suspect* it
is not a repeater problem. (Someone suggested to
try killing some of the sensitivity of the reciever).
So....looking for ideas and suggestions on what to try
next (other than double shielded jumpers to the duplexer).
Thanks for any help or ideas...
73's Rick

--
Replace NOSPAM with 1st initial and last name for direct reply!