[TowerTalk] Stange SWR/AttenuationpProblems, goes away when the sun comes up

[Jim Brown]

On 4/1/2012 8:01 AM, Richard Thorne wrote:
> All coax, connectors etc are brand spanking new.

This does, indeed, have flaky connection written all over it. What kind 
of connectors?  Who installed them, and how?  Soldered or crimped?  If 
crimped, proper tool used?

For troubleshooting -- first thing I would do is to stick an antenna 
analyzer on the coax at the shack at a time when the connection is bad 
and find all the impedance nulls. What you're doing is observing the 
behavior of that bad line as a stub. Go down as low in frequency as your 
analyzer will work, then stick those numbers in a spreadsheet to find 
possible lengths to the fault.  Do the calculation both ways -- that is, 
assuming both a short and an open at the other end, although an open is 
the more likely possibility.

This ought to get you within 5-10% of the cable length to the fault.

Another point -- BEWARE OF JUNK CONNECTORS, BARRELS, AND OTHER 
ADAPTERS.  I have had EXACTLY this sort of failure with junk 
connectors.  Any connector other than an Amphenol should be viewed as junk.

73, Jim K9YC