Group, My GPS time system consists of two Z3801A receivers with two HP cone antennas. I built a mast from plastic pipe (6" base to 2" arms) that is about 16 feet tall. The antennas are 4 feet apart, each 2' from the center of the mast. The mast rises from a deck and is fastened 8' up at the roof line. The mast sits on a 3/4" sheet of high density marine plastic fastened to the deck with stainless hinges so that the antenna can be folded away from the house and brought to the deck railing. The mast was put up in 2003.
The antenna cables are each half of a 100' coil of RG-8U. Each cable is about half in the house and half outdoors. N connectors are soldered to both ends, so no adapters are used. The cables leave the house through a waterproof boat deck fitting and travel about 5' under the deck to the mast. There's a service loop to allow the mast to be lowered, then the cables rise unsupported through the mast pipe and branch out to the antennas, which support the weight of the cables. Oh, and the location is Minneapolis, MN, USA. The problem is loss of signal during cold weather. Last winter (07-08) I lost the signal from one antenna during a cold snap, but it came back a week or so later when it warmed up outside. This winter, I lost The North antenna on Nov 22 when the low was 15, and it didn't come back. Then the South antenna went away on Dec 24 with a -17 low and didn't come back. I'm still running on holdover. I suspect that it's not a good idea to hang 20 feet of RG-8 from an N connector without some kind of strain relief, but I don't know why that would be a cold weather effect. Perhaps the center conductor shrinks more than cable and its braid, and pulls the center pin out. There's definitely an open circuit, looking at the receiver end of the cable. There's no alarm from the Z3801. Any thoughts, comments or ideas? Bill Hawkins _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
