Permanent GPS Stations - Surge and Lightning Protection: Coaxial Cable Protection

Home	About Us	Contact Us	Support	Search \|	Facility \|	PBO \| Education & Outreach

Project Support Permanent GPS Stations Overview Reconnaissance Monumentation Equipment Budgets Station Data Request Support

UNAVCO recommends replacing standard bulkhead connectors for modems (radio or celluar) with protected connectors on all permanent station enclosures (* See note below). This in-line lightning protection helps isolate the equipment in the enclosure by shunting power surges to ground. Proper system grounding is essential for this protection to work.

UNAVCO has tested EMP Protectors for use with GPS antenna cables to ensure data quality. See the Effects of LEMP Protection on GPS Signals test report for [dated] detailed information.

The following table lists the items needed to replace a single bulkhead connector.

Items	Manufacturer/Vendor	Part No.	Specifications
EMP Protector Surge Arrestor (N-type)	HUBER+SUHNER, Inc. One Allen Martin Dr. P.O. Box 400 Essex, VT 05451 (802) 878-0555	3402.17.K	Suhner Specifications
Surge Arrestor Capsule (gas filled)	HUBER+SUHNER, Inc. One Allen Martin Dr. P.O. Box 400 Essex, VT 05451 (802) 878-0555	73 Z-0-0-48
6" of Encapsulating Shrink Tube	Alpha / Newark Electronics (800) 463-9275	FIT-750-1-1/2 (1.5" dim)

Installation Instructions

Grounded Enclosure

Turn off modem and disconnect modem cables from bulkhead connector.
Remove bulkhead connector.
Insert EMP protecter with nut on the inside of the enclosure (make sure that the star washer makes good contact, i.e., electrical continuity, with the enclosure).
Slide shrink tube over the antenna cable end.
Connect antenna cable and the modem's pigtail to the EMP protector.
Slide shrink tube over the area where the antenna cable and EMP Protector meet, covering the EMP Protector and the antenna cable end completely.
Heat the shrink tube to seal (encapsulate) the connection.

Non-Grounded Enclosure

See the installation diagram.

Contact Support (supportunavco.org) for more information.

Last modified Thursday, 25-Jan-2007 23:56:49 UTC