N4DBM UHF Linked Repeaters

Providing mobile coverage from North-Western NC the NC/SC coast

This system consists of four UHF repeaters linked together, normally full time, spaced throughout North Carolina to provide mobile coverage from the mountains to the coast. It is open to all amateurs who have the capability. All UHF repeaters open with a PL tone of 77.0 Hz. The system provides somewhere around 80% continuous mobile coverage from North-Western NC (Blowing Rock, Lenoir, Hickory) to approximately 30 miles west of Wilmington NC.

444.575 MHz is located atop Grandmother Mountain near Linville, NC. Thanks to UNC-TV for allowing us to use their facility at the channel 17 site. The repeater is a Kenwood TKR-820 with an MCC RC-1000 controller. It runs around 25 watts into a Wacom WP-678 duplexer. Out of the duplexer measures around 18 watts. The feed line is 1/2 inch Heliax running into a Decibel Products DB-411 antenna on the roof. It gives 9 dBd gain and favors the south-east towards Charlotte. A Polyphaser RF protector and a typical MOV AC line deal hopefully helps with the lightning.

443.200 MHz near Stanfield, NC approximately 25 miles east of Charlotte. The repeater is a Motorola MSF-5000 running 100 watts out of a 6 cavity band-reject duplexer. Additional filtering and an ARR GaAsFET preamp helps the RX tremendously. The antenna is a Stationmaster at 125 feet on the north-east side of the tower. Feedline is Times LMR-600. The controller is an RC-850 with several link ports. The link transceiver to Linville is a GE Phoenix, and the link to Laurinburg is a Syntor X-9000. This site has over 200 feet HAAT and works very well especially to the south-east. Both link antennas are Decibel DB-436 six element beams around 85 to 90 feet fed with 1/2" Heliax.

443.825 MHz is located in Laurinburg NC just off HWY 74. This repeater serves as a second "hub" which connects Stanfield and Bladenboro. We are using another MSF-5000 and ARR preamp, 6 cavity band-reject duplexer and PD-455 Stationmaster fed with 75 ohm 1/2 inch hard line. The antenna is at 200 feet on the north-east corner of the tower.

444.725 MHz operates from a 150 foot community repeater tower just north-east of Bladenboro NC. It covers around 25 to 30 miles with an average mobile. The antenna is a Decibel DB-420 out the top of the tower fed with 7/8" Heliax. The repeater is made up of two Syntor X-9000's, one for TX and one for RX. A Decibel four cavity BP/BR duplexer and an MCC RC-100 controller to accompany. The link radio is a Motorola Radius M-100 running 25 watts to a Celwave 6 element beam pointed to Laurinburg. An Astron 50 amp P/S keeps things humming along.