QST - September 2010 - (Page 30)
A Solar Powered Repeater for EmComm
Don’t worry about keeping your repeater powered up in an emergency.
Dave Leavenworth, WV6JPL, and Pete Tiffany, KT4BW
he emergency communications (Ah) were needed along with sophisticated Customer SHARE Program, awarded a grant aspects of Amateur Radio have always charge controllers. After an initial success- to CPARC that, when combined with club been important to most operators. ful fund raising event, CPARC turned to our funds, gave us enough to proceed with this Our ability to get the message through when regional power company, Volunteer Energy project. Without their assistance, this project other methods fail is what the public has Cooperative (VEC). The VEC, through their could not have taken place. Thank you VEC! The awarding of the grant is shown come to expect from us. With this KT4BW in Figure 1. in mind, our local radio club, the Cumberland Plateau Amateur Radio The Plan Club (CPARC), recently undertook The use of solar power to run a project to convert the club VHF repeaters or other radio equipment emergency repeater from commeris not new.1-5 Most solar emercial power, with battery backup, to gency power systems have the folsolar power. lowing elements in common: the If we were to have a long power PV panel(s), the charge controller, outage, so long that the station the battery(s) and a disconnect backup batteries were close to dismechanism. A block diagram is charge, a means of recharging these shown in Figure 2. The capacity batteries would be needed to keep needed from the panel and battery the repeater on the air. New batplus the balance of these capaciteries or a gasoline powered genties was determined by power erator could be brought in. A better demand, peak loads expected, choice, as suggested by Repeater environment, cost and reliability. Trustee Paul Dorschel, W4EYJ, Receiving Energy As a starting point, we made would be solar power, not just for Figure 1 —Left to rightVolunteer Chabot, Cooperative grant from VEC. are Dick KB3YR, CPARC times of commercial power out- president; VEC representative Jim Purcell, and coauthor 1Notes appear on page 33. ages, but as a replacement for ac KT4BW, solar project manager for CPARC. mains power. This article describes the development of our club’s solar powered VHF repeater located in Crossville, Tennessee.
CPARC Repeater Conﬁguration
The CPARC 2 meter repeater is a Motorola Mitrek model T83 that uses a CAT 300 DX controller. Good coverage of the Cumberland County area is obtained by running at about 40 W into a Diamond vertical antenna mounted at a height of 50 feet. Some might argue that the repeater modified as planned will not really be solar powered, but will be battery powered, with the battery charging and recharging accomplished by use of a photovoltaic (PV) panel. The authors leave it to the reader to decide if the electrons that activate the repeater come from the battery or the PV panel.
Figure 2 — Block diagram of the solar repeater hardware. Note that the charge controller becomes isolated from the PV panel and battery when the system disconnect is in place.
Solar equipment is not cheap. Although the cost per watt continues to decrease, PV panels remain an expensive item. In addition, batteries of 100-200 or more ampere hours
30 September 2010
Table of Contents for the Digital Edition of QST - September 2010
QST - September 2010
It Seems to Us: Disaster Drills: The Last Word?
This Just In
Guide to ARRL Member Services
Up Front in QST
A Solar Powered Repeater for Emergency Communications
A Portable Antenna Mast and Support for Your RV
One Ham’s DC Power Connector Preference
Attic Antenna Experiments
The Doctor is IN
Getting on the Air
Hints & Kinks
The Flight of PBH-8
Ham Radio Manufacturing: An Inside Look
JOTA 2010 is October 16-17
2009-2010 School Club Roundup Results
ARES®: 75 and Counting
2010 Simulated Emergency Test
This Month in Contesting
2010 ARRL DX Phone Contest Results
2008 ARRL International DX Contest (Phone) Scores
The World Above 50 MHz
Amateur Radio World
At the Foundation
Convention and Hamfest Calendar
ARRL VEC Volunteer Examiner Honor Roll
Field Organization Reports
75, 50 and 25 Years Ago
Index of Advertisers
QST - September 2010