The alarm comprises a pair of small fob transmitters and a receiver plus a loud 2-inch diameter siren. Two transmitter fobs are included so that the engineer can silence the siren with the press of a button.

Here's what they look like:

Fob transmitters and receiver

Siren

The receiver, the larger black box, can be installed anywhere in or on a locomotive as long as the antenna, an 8-inch length of wire, is outside a solid metal locomotive. The receiver may work when installed in the locomotive if the transmitter radio signal can penetrate the locomotive.

The transmitters are supplied with a self-contained 12-volt battery. You may connect the receiver to your locomotive's 12-volt ignition circuit, or to a 12-volt battery.

The receiver draws very little current in the standby mode, and only 130 milliamps in the alarm mode. An ideal battery is the Power PS Sonic sealed lead-acid rechargeable which you may purchase here for $15.99. Or, you might wish to use eight AA batteries connected in series to supply the 12 volts.

The fob transmitters, the receiver and the siren are available online (or by phone order) from Marlin P. Jones & Associates. The phone number is 800-652-6733.

You may view and order the components online here:

The cost of the transmitters/receiver is $16.95. The cost of the siren is $12.38.

• The larger, stiff black wire is the antenna. You may orient it vertically (best) or horizontally.
• Leave the green loop intact. You can tuck it inside the receiver case.
• Cut the green/white wire at the circuit board. You will not need it.
• Connect the red wire to +12 volts, the positive terminal of your battery or to the positive lead of your locomotive ignition circuit.
• Connect the black lead to the negative terminal of your battery or your locomotive ground.
• Connect the white wire to +12 volts (to the red wire).
• Connect the blue/white wire to the red wire on the siren.
• Connect the siren's black wire to ground.
• You'll find a small red LED (light-emitting diode) connected to the receiver by two wires. This LED blinks when power is applied indicating that the alarm is armed. You may mount this anywhere you wish, or simply ignore it.

Alternately, you could install a normally-closed push-button switch in series with the +12 volt supply lead (the red wire). Pressing the switch momentarily will turn the siren off.

Should you have any questions, feel free to phone Charlie Downs at 602-326-4867 or send him email.