RT Plus Transmitter User Guide

Features you will hear

1. Fast pulses. Twice as fast as most transmitters, so the receiver locks the direction sooner.

2. Low-battery warning. A timer plus a live voltage check. It warns you if you install an old battery. You hear a double beep every 10 pulses when about 7 days remain.

3. Apollo 13 Mode. After 24 hours of continuous running, the transmitter treats the bird as lost. The pulses get shorter and less frequent, so the battery lasts longer.

Install the battery

The RT Plus uses a 1/3N lithium photo battery. Marshall recommends the Duracell DL1/3N. Put the positive side toward the lid. The positive side is marked with a plus sign. Screw the lid on with your fingers. The round battery spring pushes back on the lid so it does not unscrew. The transmitter starts as soon as the battery is in.

How long the battery lasts

About 15 days of continuous transmission on a new battery. A double beep every 10 pulses means about 7 days remain.

Turn it on and off with the magnet

Hold the magnet near the base of the antenna. You will hear 5 fast beeps on the receiver when it turns off, and 3 fast beeps when it turns on. The short wait keeps a brush of the magnet from turning it off by accident.

Wash and inspect

1. The RT Plus is waterproof. Wash it with hot water. Dry the inside of the case and the lid before you install a battery.

2. Replace the antenna at the first crack or bare wire.

3. On a tail mount, inspect the spring. Replace it if you see a crack or if it feels weak. The blue washer holds the spring on the antenna.

4. On a leg mount, inspect the bewit slot for wear or thinning.

Replace the antenna

The antenna is 7 and 7/8 inches for 216 megahertz, and 10 and 3/8 inches for 173 megahertz. Use only a genuine Marshall antenna with Power Line Static Protection.

1. Unscrew the antenna protector.

2. Unscrew the old antenna with your fingers.

3. Screw the new antenna on hand tight. A small bead of quick-drying epoxy at the base is fine.

4. Put the protector back on.

What range to expect

Tested past 100 miles, line of sight. In the western deserts of the United States, hunts have run from 3 to 50 miles, depending on height, ground, obstacles, and radio noise.

How it mounts on the bird

Match the photo to the hardware you ordered. The bird photos show the leg and tail methods. They use a GPS transmitter so you can see where the hardware sits.

Point the receiver

1. The signal from the RT Plus is strongest when the receiver antenna lines up with the transmitter antenna.

2. A bird on a perch holds its tail nearly straight up. Hold the receiver elements straight up.

3. A bird on the ground can leave the antenna nearly flat. Turn the elements flat and listen again.

4. If you can hear the signal both ways, use the flat position to pinpoint the bird.

Change the frequency without opening it

The channel can be changed without opening the case. The range is 216.000 to 219.995 megahertz on 216 megahertz models, and 173.000 to 173.995 megahertz on 173 megahertz models. Pulse width, pulse rate, and the low-battery point can also be changed. The defaults are 110 pulses per minute, 30 milliseconds, and about 5 days before low-battery mode. Send it to Marshall Radio. The charge is 35 dollars plus shipping, and the turnaround is one business day.

Warranty

Marshall Radio Telemetry warrants that the RT Plus will be free from defects of workmanship and materials for three (3) years from the date of purchase by the end user. Return a defective transmitter directly to Marshall Radio Telemetry and we will repair or replace it and return it free of charge. Damage from misuse or normal wear and tear is not covered, and the warranty is void if a non-Marshall antenna has been used. Marshall Radio is not responsible for damages or loss beyond the value of the transmitter itself, including but not limited to the loss of a bird or lost time.

This device does not interfere with television reception or Federal Government radar.