ARECC Antenna System
There are 21 coax cables that run from the radio room to the tower lightning protection box. Four of the cables are in a box at ground level (one for each operator positions) and provides for auxiliary/secondary antenna for either operating or testing the antenna(s).
There are four operator stations, OPS-1, OPS-2, OPS-3, and OPS-4. The antenna system utilizes several multi-band antennas to minimize switching or manual coax changes at the operating positions.
OPS-1 utilizes the 6 meter, HF tri band beam and rotor. The Mosley 10-15 & 20 meter beam is 25+ years old and is due to be replaced with a newer antenna that will provide more band coverage. Our goal is for this position to have access to 6 through 80 meters as a minimum; 144, 220 and 440 MHz coverage FM voice and digital and is considered the Primary Voice Net Operator Position.
OPS-2 uses a 10-80 meter wire dipole constructed of copper weld wire. It too has 144, 220 and 440 MHz coverage. OPS-2 is the Secondary Voice Net Operator Position. Both OPS-1 and OPS-2 have digital capability via a sound card interface, and computer driven CW interfaces that can be used via software.
OPS-3A and OPS-3B dual operator positions for digital communications and is planned to have a HF radio and antenna system that will support HF-ALE and FLDIGI on multiple band segments 10 through 80 meters.
The 144-220 and 440 radios will utilize Kantronics TNCs capable of 1200 & 9600 baud that includes the operating modes APRS, PACKET and AIRMAIL.
D-Star digital voice and data communications will also be available for utilizing D-Rats, D-Chat, DSTAR TV and other DSTAR based software.
OPS-4A & 4B is the information gathering and room display control operators position. It is outfitted with 144, 220, and 440 MHz transceivers and can be used as another voice station.
Plans are to add a HF vertical screw driver style antenna taking advantage of the building's all metal roof as a ground plane for 6 through 80 meters. This position has access to the 800 MHz ITAC communications for contacting the 911 center, EMA and weather service in the region.
An Emergency Alert S.A.M.E. weather radio is part of the equipment in the Amateur Radio Emergency Communications Center with weather alerting for Indiana counties west and southwest of us as well as the counties that border Butler County in Ohio.
This is a photo of the new 6 meter beam. We replaced the top thrust bearing with a 3" heavy duty bearing, the main mast pipe the HF beam is attached to is 2.5" diameter schedule 120 steel pipe. The mast pipe holding the 6 meter beam is 2.25" diameter schedule 80 steel pipe. The clamp set is a commercial pair of Andrews heavy duty clamps. The rotor is a Hygain Tail Twister the control cables are also surge protected.
Each of the 25 coax cables and the rotor cable that enters the building must be protected by a Polyphaser or I.C.E. surge device. (Our rules to protect our equipment and operators-we do operate Butler Warren CO SKYWARN from here!)
These devices are bolted in place on the sides of the cable entry box. Each device in the enclosure is individually grounded to the grounding bus bar, that is tied into the tower and building ground system.
On the top and back of the box is a 75 ohm 4 port 30-1300 MHz pre-amplifier (grey box) that amplifies a discone scanner antenna.
The signal is used for on 700-900 MHz scanners, weather radio and TV signals.
Those 4 cables going into the building are RG-11 75 ohm low loss cables.
The seven LDF-4-50 Heliax cables going into the building are for the tri-band antennas on the top and middle levels of the tower on 144-440-1.2 GHz, 144-220 & 440 MHz and 800 MHz.
The RG-213 cable runs are used for three antennas mounted lower on the tower that cover 144-220 & 440 and the 6-160 meters feed lines.
With plans of a 1500 watt amplifier at OPS-1, four antenna cable protectors have been upgraded from 350 watt maximum polyphasers to ICE 8 KW protectors on four lines setup for the HF radio.
A dedicated 6 meter cable, one to ground level connection point, one to the main beam antenna (10-15-20 meters) and a spare to use for a permanently installed 40-80 meter antenna system.
The four 350 watt polyphasers have been re-purposed to protect scanner equipment, and two new lines added to the box March 2012.
All lightning protection is common grounded to the 1/4" thick copper bar in the bottom of the box , the tower, schools electrical system and equipment in the room.
The three (3) ropes are used to launch temporary and test antenna systems. The other ropes are used to lower the tower end of the multi band dipole antenna for maintenance.