On Aug 19, 2008, at 7:09 PM, James - KB7TBT wrote:
400-Series Coaxial Bulk Cable- Available by the Foot or Reel
I recognize the CommScope brand name in this website, and know that lots of commercial folks use their hardline... but the other manufacturer I don't recognize.
"True" LMR-400 is only made by Times-Microwave. There are a lot of "copy-cats" on the market now, but little engineering data on whether or not it performs to rated specifications.
Has anyone on the list tested any of this "400-series" type cable from either of these two manufacturers to see if it lives up to real LMR-400 specs?
I hate to say it, but I've been burned enough times by the old adage, "You get what you pay for" that I'm leery of these LMR-400 "series" copies.
LMR-400 has also been traced to PIM (passive intermod) problems on many commercial sites when used in feeding repeaters, due to the "foil over braid" design, and many repeater owner/operators won't use it anymore. (Every little "bump" in the braid touching the foil is another tiny little junction where diode-behavior can create IM mixes.)
Still good specifications for simplex services like satellite, no doubt -- but just mentioning that it does have some limitations/ downfalls in duplex service on FM repeaters.
-- Nate Duehr, WY0X [email protected]