2001.06.21 - NLARC Repeater Site Inspection

Reason for Inspection:

The 146.34/94 repeater has been exhibited a squelching problem that has made the transmitter retransmit what sounds like audio oscillations that resemble intermodulation distortion.

Course of Action:

Jim Byrd and John Parker visited the site and performed the following items:

• The repeater controller was relocated from the top of the duplexer to the top of the packet digipeater cabinet.
• The repeater controller cabinet was grounded with a strap to the side of the building frame.
• The repeater controller interface cable that enters the 146.34/94 cabinet was relocated as far away as practicable from the coaxial cables that carry RF from the repeater.
• The edge connect repeater control cards inside the 146.34/94 repeater rack were reseated.

Results:

• In the short term it was noted that the squelching problem was no worse but slightly better.
• As of 2001.06.21, it has been noted that there was no effect on the problem whatsoever.

Further Action:

• It would seem prudent on the next visit to check the antenna system for faults that could lead to spurious behavior of the receiver. This includes but is not limited to:
  • Wet/exposed/corroded connectors.
  • Antenna/coaxial cable damage due to lightning.

Web page operations: James E. Byrd
Responsible NASA Official: Richard S. Eckman