Saturday, February 18, 1995

147.39 Repeater #2

I've been digging back through history a bit, to document the local repeater stuff I was involved with over the years. This was the 2nd 147.39+ repeater in Clayton. It was put on the air in February of 1995. Photos and info on the previous 147.39 #1 have been lost, though I know it was a RCA series 1000 repeater. Parts of it were used to build the 147.39 #3 repeater. From the historical data on the old website:

'Welcome to the WB4IUY repeater in Clayton, NC. PL 88.5. Part of the TEARA link system' is the feminine voice of AC4QD heard on this repeater every 10 minutes. This repeater is sponsored by the Triangle East Amateur Radio Association (TEARA). The repeater is located on private property, just south of Clayton near hwy 42 west. 

This picture on the right is the repeater (in the gray enclosure), sitting atop a _LARGE_ set of DB Products 6 cavity duplexers. The repeater is a Motorola MastrPro, with many modifications. The controller is a MCC RC-1000 with the newest firmware and a homebrew voice ID'r. An ARR GaAsFet receiver preamplifier is also installed internally to improve weak signal performance. This is an open repeater, although it does require a sub-audible tone of 88.5 hz for access. This is necessary to control unintentional interference generated by commercial sources and that which occurs during band openings. Additionally,
several cavity filters are required to maintain control of the repeater and minimize interference from local hi-powered paging systems and commercial repeaters, as well as reduce the receiver desense caused by the high levels of RF from local co-located systems on a broadcast tower. Some of these cavity filters are shown in the picture to the left.

This repeater also shares it's feedline and antenna system with the W4RAL-6 BBS digi-peater. The next photo on the right shows parts of the mixing network that was designed to allow the voice repeater on 147.39/99 and a digital node on 145.01 to cohabitate the same system successfully.

This repeater replaces the previous RCA series 1000 repeater, similar to the one described on the 147.300 repeater page. Being in a high spot, this tower is a regular attraction for lightning strikes. The previous repeater was destroyed by lightning, and this machine has been rebuilt (nearly from the ground up!) twice since it's installation in Clayton during the spring of 1997.

The tower structure is about 200 feet tall, and the repeater antenna occupies the top perch. The repeater's primary antenna is a Sinclair 4 bay dipole array fed through about 300' of 1 5/8"
Andrews heliax. The Clayton site is about 335 feet above sea level, and the antenna is about 535 feet above sea level!

The photo below shows the tower structure. At the very top is the repeater's Sinclair 4-bay dipole array.

 Dave WB4IUY