The 537 SYSTEM
OHSEP / SkyWarn / ARES / RACES
in Lafayette Louisiana

Status: 1/28/2014

537 System Repeater Available for Regular Amateur Use

The Emergency Preparedness Repeater System in Lafayette Louisiana is the 145.370 repeater system (an Amateur (HAM) Radio System). The 537 Repeater System is sponsored and managed by the Lafayette Repeater Association (LRA). The system is owned by the Lafayette City-Parish Office of Homeland Security and Emergency Preparedness. The repeater trustee is Steve Mahler (KF5VH). Operational policy of the 537 System is set by the LRA board. Members of the LRA board are currently: Mr. Steve Mahler - KF5VH / Mr. David Moore - KC5UKQ / Mr. Mike Gervais - KC5ZMF / Mr. Jeff Mahler - W5JSM

The need for the 537 System was apparent during Hurricane Andrew as Lafayette Louisiana was being impacted. The ARES/RACES groups did not have solid communications between the Office of Homeland Security and Emergency Preparedness (OHSEP) Emergency Operations Center (EOC), the various shelters and the incident sites.

In 1994 a couple of local hams (Tom N5WDG and Steve KF5VH) finished a design for a distributed repeater system that would improve communications to local shelters and provide a lot of amateurs the chance to work on the construction of a repeater system. That design allows for multiple receivers to be placed as required to provide the desired coverage and a large central transmitter that radiates enough power to allow use of handheld (HT) radios in the shelters.

The 537 System is not designed to be a wide area system. The transmitting antenna is fairly low (only 100 feet), the radiated power is fairly high (for this part of the country), providing a solid signal inside many structures. But, by design, the low antenna limits the range of the system to Lafayette Parish and the edge of surrounding parishes.

The 537 System is also designed to make use various advanced techniques to allow alerting of its user population. Most of the alerting techniques are for SkyWarn operations but may be used for any reasonable purpose. The System also supports these operations:


Let's start with an overview of 537 System construction. The repeater is fairly unique in a couple of areas.
Here is a simple picture of the configuration of the pieces.

The 537 System alerting and speed dial slots are available to all 537 system members. The easiest way to become a member is to join Lafayette SkyWarn. Access to the system is without charge for SkyWarn members. If you just don't enjoy weather watching, contact the repeater trustee.

How Do I Use the 537 System?

The 537 System is full featured and easy to use. Here are the basic rules:

  1. The easiest way to start is using the central receiver. Set your 2 meter transceiver for 145.370 with a negative 600 KHz offset. You must set your radio to transmit a 103.5 PL tone. Set your radio to decode 103.5 PL if that option is available.
  2. There are a lot more time delays in the transmit chain of this system than a little repeater. Please make sure you press your PTT and pause just a 1/2 second before beginning to speak.
  3. Repeater features are activated by keying the repeater and sending touch-tone (DTMF) signals. Enter a 1 through 3 character command code to request a function.
  4. The execution of the command code will not begin until you unkey your transmitter.
  5. You may request multiple commands occurring sequence. To do this, enter the first command code, then enter the '*' key, then the next command code, etc. You do not need the '*' on the last command code. But, when you do this each command begins in sequence when you enter the '*'.
  6. Before the 7K controller was added (Summer 1999) you needed to copy morse code or remember tone patterns to know about the state of the repeater. Now the 537 talks and the courtesy tone alerts you to three things. The 'waterdrop' courtesy tone is used in open and normal operation. The waterdrop changes to a triple beep to identify an alarm or weather condition. A double beep means the audio is arriving from the linking system.

The 537 System uses a 4th generation implementation of the orginal 537 code (for a 6K controller). The orginal code was enhance for 7K operation and tested on the Opelousas Area Amateur Radio Club (OAARC) 147.150 and N5MEG 443.9 repeaters. LRA thanks all OAARC members and N5MEG for serving as a test site during all of the software development. This also means that 90% of the commands are identical between the three repeaters.
You can obtain the command function summary.

REMOTE RECEIVER LOCATIONS

Receiver Name Frequency PL Tone Location
CENTRAL 145.37 minus 103.5 Lafayette, Congress and Cajundome
SOUTHEAST 145.37 minus 94.8 Broussard, US 90 at the Southeast Parish Line
SOUTHWEST 145.37 minus 141.3 Johnston St. Southwest of the Mall, at Fire Station #13
WEST 145.37 minus 114.8 Duson, I-10 near the Western Parish Line
NORTH 145.37 minus 127.3 Carencro, I-49 near Exit 8

NOTE: The 537 System always transmits with a 103.5 PL tone. Your receiver PL should always be set to 103.5 or turned off

The areas indicated in the drawing above are designed to show the concept of the remote receivers used in the 537 System. Receiver coverage extends beyond the rings for each receiver. The drawing shows the overlap of receiver coverage and indicates the best expected performance areas for handheld use of the repeater. Users may use any receiver that works for their radio configuration. Users may also coordinate and operate their own receivers. Again, the rings are conceptual and do not represent a scientific placement based on measurement or engineering calculations.


To look up a ham by name or callsign please click here..... QRZ.
To lookup up possible areas of traffic congestion in Lafayette Parish please click here..... 911 Traffic

This website designed and maintained by Steve Mahler, KF5VH. Last partial update 07/27/2013. To mail a letter to KF5VH please click here.....

mahler@louisiana.edu