147.390+ PL 88.5 HZ
'WB4IUY repeater in Clayton, NC. PL 88.5' is the voice of WB4IUY heard on this repeater every 10 minutes (when in service). 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 and beige enclosure), sitting atop the new repeater and node enclosure at the Clayton NC site. It is constructed in a RCA series 1000 repeater cabinet, and uses an RCA receiver and exciter strip. The PA is from a GE MastrII, the power supply is largly homebrew, and the interstage amplifier (between the exciter and PA) is a modified Aerotron Mpac module. An ARR GaAsFet receiver preamplifier is installed internally to improve weak signal performance. The controller is a refurbished SCOM 6K, rebuilt from parts of two controllers previously destroyed by lightning, and updated to include a digital delay to help hide squelch bursts. The digital voice announcers were built by Interalia and have been modified to include large capacity outboard battery backup. These Interalia units previously served time in the telephone industry. The repeater has 3 additional dc blowers installed to keep things cool during long transmissions. Circuitry was added to include CTCSS encode/decode for linking and interference control. A motorola UHF Micor was used for remote control and linking via RF.
This is an open repeater, although it may require a sub-audible tone of 88.5 hz for access on occasion. This is necessary to control unintentional interference generated by commercial sources as well as that which occurs during band openings. 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 local 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-4 BBS node. This photo 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 co-habitate the same site sucessfully.
This repeater replaces the previous GE MastrPro repeater, described in the link info contained HERE. 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 from the ground up since it's destruction during the spring of 1997. The next photo to the right is a picture of the repeater with it's front panel removed, exposing the programming ports of the voice announcers and other components. That's Steve KD4WIW in the rear of the repeater, after having just installed a fresh batch of PolyPhaser lightning protection devices into the repeater's feedline. We DON'T want to rebuild this any time soon!!
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. You can view some pictures taken from the top of this tower by clicking HERE!
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