Current List of DFMA Repeaters and basic specs.
147.825 – 147.225 82.5 Hz PL Autopatch, IRLP Node 8658, Battery backup power.
222.660 – 224.260 (No PL) Autopatch, Battery backup power.
448.1375-443.1375 DMR Digital Full time link to DMR repeaters in Carolinas & Virginia; On-demand access to DMR repeaters world-wide; Battery backup power.
144.850 – 145.450 82.5 Hz PL Autopatch; Remote base 2 meters & 220 MHz.; Generator backup power.
449.100 – 444.100 82.5 Hz PL Autopatch; IRLP Node 4441; Remote base 2 meters & 220 MHz.; Generator backup power.
449.450 – 444.450 100.0 Hz PL Generator backup power.
Note that the rest of this page is due for a complete rework since much has changed.
[click here for system map]
The text below describing the DFMA's extensive repeater system includes representative pictures for each site. For more complete and detailed picture coverage of the system, check out the Picture Gallery. All photos by NC4CD. (Thanks Charlie!)
The Hillsborough Repeater Site - WR4AGC
Top of the Hillsborough Tower with the 225 antenna at the peak. (photo by NC4CD)
The Hillsborough site includes the following repeaters.
- 147.225+ repeater driven by a Kenwood Transceiver and a TPL power amplifier. There is no receiver at this site for this 2 meter repeater. Instead input from a number of remote receivers is relayed to the site and the best signal is selected by a Hall voter. This gives the repeater extraordinarly wide receive coverage. For more information on the rmote receiver sites, see below.
- 444.450+ repeater driven by a Kenwoord Transceiver and TPL power amplifier.
- 224.260- repeater.
The repeaters are controlled by a common SCOM controller which supports open autopatch through a shared phone line. The controller also allows access to remote base transceivers. Considerable battery backup power is supplied so that the repeaters can operate for many hours in an emergency.
(Note that as of now, the remote receivers are not active and the 147.225 receiver is with the transmitter in Hillsborough. The voter system is being upgraded and other adjustments are being made.)
Equipment in the shack (photo by NC4CD)
The Durham (VA Hospital) Repeater Site - WR4AGC - since 2015 on TV Hill
The Durham VA site includes the following repeaters.
- 145.450- repeater. This repeater has been designated the Durham ARES repeater.
- 444.100+ repeater. Starting November 2015 a PL tone of 100.0 is needed to transmit
These repeaters are controlled by a common controller which supports open autopatch thru a shared phone line. The controller also allows access to remote base transceivers.
This equipment is fairly old including a vacuum tube power amp and an obselete controller. It is soon to be replaced by equipment identical to or very similar to the equipment employed at the Hillsborough site. The following picture shows the rack of new equipment which is to be installed there. (This new equipment is now at the TV Hill site.)
The new VA repeaters almost ready to install. (photo by NC4CD)
The 225 Remote Receiver Sites
The 147.225 repeater has it's transmitter located at the Hillsborough site, the "Hill". It is linked to seven remote receiver sites. These receivers relay received signals to the Hill with link radios. There a Hall Voter picks the best signal (if there are more than one concurrently). Below are representative pictures for each site: (more descriptive text to come)
This site includes a complete (but older) back-up 147.225 repeater.
[click here for system map]