[NLRS] [] VHF/UHF rotator loops

[scsueepe at mtcnet.net]

Bill, my 2 cents here..

Used LMR-400, LMR-400UF, LMR-600, LMR-600UF and 1/2" superflex for rotor loops.

The LMR-600UF was not good, seems like the center conductor migrated over time.  And one always had to solder the center conductor due to stranding center...

The Superflex was good and did that for years on 902 and 1296.  Now those transverters and amps are on the tower mast, so I use LMR-400 as the IF cable and rotor loop.

For the rotor loops, I now use combination LRM-400 and 600 depending on frequency.  Is it stiff?  You bet, but I do multiple smaller loops (like 3 turns around the mast) so none of it seems to compress too much, or expand too much.  Kind of like a spring.  The multiple loops are taped together and support each other in a way.  Taped liberally where then transitioning to the vertical mast so no stress is put on the connector whatsoever.

99% of the connectors used here in the last 10 years are spring center pin captive and crimp braid, no soldering, then heat shrink cover.  N-Male Times microwave EZ-600-NMH-X or EZ-400-NMH-X.  High power all the way up thru 1296.  Never had an issue while using the Times Microwave LMR tools for cutting, stripping, deburring and crimping.  All vertical runs up the tower are LMR-600 except for HF.  Not a single failure or replacement needed so far.

As for weatherproofing, I quit using that goop tape, worked, but messy stuff if you want to remove or change something.  Over the heat shrink piece that comes with the times microwave connectors, I use the silicone self-adhesive tape over everything, then retape over it with high grade 3M black.  Been working good.  Easy to cut and take off if you need to redo something.

Only solder connectors here are PL-259s from DXE... solder center pin only, and crimp body.... Not many in use here, just where needed.

Never tried a 3rd party cable, was always wondering about Davis RF bury flex... but never got around to trying it.  Never used 9913, was always afraid of the water ingress stories...

I have bought most of my LMR cable thru Bill at Pulse Products in Minneapolis.  Scanner put me on to him a long time ago and he has been a great resource for my cables for several years.  Its been a few years since I called him to order anything, not sure if he is there anymore or not, or if their numbers are still competitive.

73 and GL

Mike - KM0T

-----Original Message-----
From: nlrs-bounces at mailman.qth.net <nlrs-bounces at mailman.qth.net> On Behalf Of Bill Davis via NLRS
Sent: Saturday, March 19, 2022 12:19 PM
To: NLRS Reflector <nlrs at mailman.qth.net>
Subject: [] [NLRS] VHF/UHF rotator loops

  This spring I need to plan on replacing many of my coax drops from the antennas to the hard lines at the top of the tower, including the rotator loops. The old coax lines are over 20yrs old and are 9913 superflex (NOT cellular coax). I have had no KNOWN issues until the day before the arrival this year of "real winter" when I discovered WATER in the 1296 coax. (Elevated SWR) which had NEVER been observed in the past. I have never known this to be an issue before. Given the lateness I did no trouble shooting of this cable since I would have had no opportunity to replace it regardless. I just drained it for 2 days.
  The question is --- "this day and time" what are people using for such cables. LMR400UF ?? or ??.  It looks like LMR400UF is over $2 a foot. I sure do NOT look forward to this job and want the job to last without service for hopefully 15yrs or more. I HAVE NOT used any crimped type connectors before. Not sure if I will this time or not. All connecters solder type and are type N with the exception of a couple. (2m 6m)
  Comments - recommendations - etc are being solicited. 
  Are there cable brands to avoid since so many different outfits are selling LMR400UF "equal" coax? Retailers? etc
  Thanks 73  -  Bill  K0AWU
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