We are a multi-county Community Preparedness Group

with goals of preparedness & mutual support at the community

level. Should a disaster/emergency situation develop, we

recognize that the local community members will be the

most effective tools in the disaster response “tool box”



Larry Bowers W4LQB



Cross Band Repeater Project - Firetower Hill

File & Chart For June 12, 2017 Meeting

Katiepie's Country Kitchen

Columbia, TN

On Saturday, August 23, 2017, Jim Petit KB8KEI, David Quirk KM4FSI, and myself installed a dual-band (VHF/UHF) antenna on a fire tower in North Maury County. David securd access amd permiion from the Forestry Service for us, the Community Preparedness Network, to do so. The intent is to be able to quickly field a cross-band repeater in the event of an emergency/disaster such as a earthquake out of New Madrid or widespread grid failure due to a extreme solar event. The tower address is 4398 Fire Tower Rd, Columbia, TN 38401. The cross street is Chestnut Ridge Rd.

Here is a overhead picture of the sight:

The feedline (LMR400) is terminated with a PL-259 connctor and coiled at the base of the tower for quick connection to a B/M radio.

The Comms CONOP is simple: drive a B/M unit on site, connect to the tower antenna, put the radio in cross-band repeat on the appropriate channels. Once operational, Net Control conducts subsequent operations and the Net Control operator can be anywhere within range of the radio/repeater. The vehicle can be left on-site for radio power. Alternate batteries can also be used and charged for long term operation if necessary. In the future it will be possible to add a cheap solar system consisting of a couple panels and charge controller to maintain charged batteries at the site. Physical security of the radio/repeater is maintained by physical presence, locked vehicle, or lock box.

Initial radio tests with the antenna showed great coverage over many counties:

Many MTEARS networked UHF reeaters (Hickman. Southport, Deason, Shelbyville, Wayne, Lawrenceburg, & Heritage) - these are just the ones we had programmed at the time of the tests.

All Lawrence County VHF repeaters (with the exception of Collinwood), Hohenwald UHF/VHF, Franklin UHF, and others.

Our current selection of repeater frequencies are: RV = 147.54 & TU = 446.025

These frequencies were monitored for some time, with the tower antenna, and no activity was detected. These frequencies can be easily changed should interference issues develope in the future.

We are planning on two short periods of characterization Net testing; 1) The first being of limited participation to make sure all works as planned. 2) A Net with as much participation as possible so we might better characterize the usable range of the sytem for both HT and B/M radios.

Checkins should include: Call, Name, Location, and radio TX power.

Although dual band radios are not required to participate, they will allow one to hear all participants. Dual band radios should be set internally to Mute:RX to remove tehe potential for feedback between channels. As implied by the channel names, TU and RV, participants should set their MAIN channel to UHF and attempt to enter the repeater at 446.025. If you can get into the repeater, then you should have no problem receiving on 147.54. If you can not get in on the 446.025, then try switching the MAIN to 147.54. If you get through the repeater, then Net Control will hear you on 446.025. Net Control must be sure that their MAIN is set to 446.025 to respond to th checkin. If a checkin has only a UHF radio on 446.025, then Net Control will see this on his VHF 147.54 channel. In order to respond to the checkin, Net Control must switch their MAIN to 147.54. So Net Control must be sensitive to which channel a checkin is received on. But all single-band radios can play a part and help out with the testing. It should be emphasized that all single-band radios are accomodated in the cross-band repeater. The limitation of the single band radio is that the user may not be able to hear all participants. In this case, relay by the Net Control (or others) is required.

In addition, Bill Reed W4WRR, may want to setup a short Maury County ARES Net so that he can characterize performance among the group.

All inputs and comments are welcomed, Larry W4LQB

View or Download

Files & Charts Used at Club Meetings


On The FIRST MONDAY Of Each Month @ 6:30 PM At

67 Hudson Road, Ethridge, TN


Direct All Questions To Larry Bowers W4LQB




Thursday Nights Before The MARC Net

6:30 PM Early Check-In On The

Lawrenceburg Repeaters

(See FYI Below)


7:00 PM Regular Net On The MARC Repeater

147.12 MHz (Tone 127.3)




Lawrence County Repeater Info

Up until recently, the multiple Lawrence County HAM-band VHF repeaters were linked in a single system. Recently Shelton Barnett (Lawrence Co EMA) de-linked the system and returned each of 6 repeaters to independent operation. The TX/RX frequencies for these repeaters (in your radio program) remain the same, however, there is a separate tone code for access to each repeater. In your radio program, the RX/TX frequencies for the repeaters are:

RX = 146.655 MHz

TX = 146.055 MHz

Locations And Tone Codes For The Repeaters Are:

Lawrenceburg  100 Hz

St Joseph  107.2 Hz

Leoma  114.8 Hz

Summertown  123 Hz

West End  131.8 Hz

Collinwood  141.3 Hz

Everyone should reprogram their radio(s) for these 6 repeaters. The first one remains the same so you will only need to add the other 5. If you need help with the programming, and you have a ANYTONE radio or Yaesu 8800, call Larry W4LQB at 931-762-7522 and arrange a time for him to help you. Make sure you bring your radio(s) !


Fong's Triband Antenna

Fong's Triband Figures

W4LQB Larry's Solar Panels

Cross Band Repeating

Solar System Design

Solar Water Well Pump




Larry Bowers W4LQB