Repeaters on  the Link System

(Backbone Hub)
West Raleigh, NC
K4JDR Linking Repeater

VXR 5000U Vertex

  The K4JDR Backbone Hub Repeater consists of a commercial Vertex VXR 5000 with a Pacific Research, RI-310 Controller v2.11 including a 120 minute DVR, and AD-3 audio delay board @ 62.5ms delay.  The Repeater is presently Running a Henry UHF Amplifier at 85 Watts out of the duplexer with .10 watts reflected ( 1 : 1 ) VSWR. The antenna at 320 Feet AGL. The site is 468 Feet ASL. 

DB-4070 BP/BR duplexor cavities

DCI Band Pass Filters are used on the link radios and repeaters to filter out other services outside the Amateur Bands. Click here to View Graph 1 and View Graph 2 

RFI Surge Suppressor Sentry RFI Surge Power strip

RS-50BB, 12 V Power Supply. 

  Polyphaser IS-50NX Surge ArrestorEAR #5120 Weather Radio (SAME)                                                   
Decibel, DB4001-1 band pass filter cavity for 162.450mhz

Home Brew WX interface and modifications
Home Brew, 90 sec. WX Broadcast Circuit
Home Brew, Wx Radio, Reset Circuit
Home Brew, VHF 1/4 wave Weather Radio Antenna

Home Brew, Notch, 1/2 wave stub filter.
6 Ft. 19 inch Repeater Rack Assembly



Communications Building at the 441.725 Hub and 444.675 site in Raleigh  

A look into the Building, the 725 Hub and 675 is on the left at the end.
  A shot of the 360 ft. Tower  
Rob Noble, a Cary Firefighter and tower rigger for Nav-Com Communications, climbing the Raleigh Hub repeater tower inspecting cables and removing a UHF link antenna.

If you are interested in my field notes which contain many schematics and information on the equipment and addition items I had to build, please click Field Notes here or on the side bar and visit our Yahoo site for schematics.  The notes are in a PDF or jpeg format so you will need Adobe Acrobat Reader available at Adobe's web site.

Various photos 

Old Clayton 444.150 site installing a 6 Element Link antenna to point at Raleigh Hub.  This tower was taken down in 2015 by a dump truck dumping and driving into the guy wires.   This was a great site, we miss it.

Battery Backup System at Raleigh Hub.
EZ-Gate 80 Switching Module

Battery Backup autodialer

EZ Gate 80 Charging and switching module with a PowerWerx LVD-35 Low
Voltage disconnect set at 11.8 Volts.

Coats 444.550 + 100 PL Repeater site.

Chris, KG4GRB took photos at Coats site back in 2005 towards Barclaysville.

Base of antenna at Coats site

Coats antenna

Wendell 444.875+ 100 PL repeater site

AirCrane Performing Tower Work at Wendell Site


More photos and organization coming as time permits.

video links:


©2001-2018 Carolina 440 UHF Link System, A Non-Profit Division of Southeastern Emergency Communications Network, Corp. All rights reserved.
Ronnie J. Casey • K4JDR at • 84 Angie Road Raleigh, NC 27603-7336
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