Adept Rocketry - Radio Location and Tracking Devices

T400 Transmitter - 2 Models - $59.00 each

Quick Start Instructions

T400AM - transmits AM burst tone signals

T400CW - transmits keyed on and off CW signals

ANT440-3 - three-element directional receiving antenna - $29.00

ANT440-7BP - seven-element directional receiving antenna - $65.00

CABBNC3 - accessory cable, 3 feet long - $6.95

SMABNC - accessory adapter connector - $4.95

The ANT440-7 seven-element antenna (picture at bottom of this page) offers more gain (sensitivity), and a sharper directional pattern. However, the ANT440-3 still works quite well. The ANT440-7BP (Back Pack) antenna breaks apart in the middle of the boom for easy carrying when broken down. Each of the antennas disassembles into a small bundle for carrying.

T400AM and T400CW - Transmit Frequency: 433.9 MHz. Battery Life: 2 days typical.
Measures .55" wide by .67" thick by 2.7" long.
Weight: 8 grams. Weight with battery installed is 14 grams (1/2 ounce).
Fits inside a tube with a minimum ID of .68 inch (17.3 mm), a loose fit in an Estes BT-20 body tube.
Accessory required: one 12-volt alkaline lighter battery (included).

You may be able to supply your own BNC to BNC cable, and possibly an appropriate antenna. The SMA to BNC adapter connector is necessary for use with the Icom IC-R2 Receiver shown below, and with some others. One low cost solution is to use a T400AM transmitter with the IC-R2 in AM mode. With the other three receivers shown below (each has CW mode), it is suggested that you use the T400CW transmitter.

The Adept T400AM and T400CW transmitters transmit on 433.9 MHz, and because of the modes used, and because the signals are of the repeating type, and due to the power level, they do not fall under the Part 15 rules of the Federal Communications Commission, FCC. The transmit frequency used falls within the 440 Amateur Radio (ham) band. An Amateur Radio License is required.

When ordering a T400 transmitter, Adept requires that a copy of your Amateur Radio License be included with the order. When operating, the transmitter will periodically identify by sending your call sign in Morse code.

These transmitters have been tested at a distance of 15 miles line-of-sight, and the signals were still receivable and very useable, both models. The expected range when used at high altitudes is considerably greater.

There are numerous commercially available receivers that are ideal for receiving the signals from Adept transmitters. Actually, you can receive just about anything else with these little guys too, including the illegal Walston transmitters and the illegal "Rocket Hunter" transmitters (not with the IC-R2), commercial AM and FM radio stations, nearly all the ham bands, shortwave, CB, baby monitors, the Family Radio Service, ship-to-shore, police, aircraft, and so on and so on. You just need to use the appropriate antenna for what you wish to receive.

These receivers, some of the first that were available, are shown here in comparable scale. The Alinco is slightly larger than the Icom IC-R10. The Yaesu is slightly taller than the Icom IC-R2. The smaller units are newer units. The Yaesu is the most recent of the four in this picture. The smallest unit, the IC-R2 does not receive CW or Single Side Band signals, and it is the cheapest, about $140. The other three units receive "all modes" and are comparable in price, about $300 from most Amateur Radio (ham) supply stores. Check the ads in recent ham magazines such as QST.

There are other receivers that will also do the job. The key words are "Communications Receiver." They must be able to receive AM or CW signals on the particular frequency of use. Scanners typically receive only narrow band FM signals, and sometimes receive AM signals only on the much lower frequency aircraft band. You will not be able to use the T400 transmitters with an FM receiver or FM handy talkie unless it also has the ability to receive AM and/or CW.

However, new receivers are constantly showing up in the pages of QST Magazine and others. Now there are several dual- or triple-band handy talkies that are FM transceivers with the added capability of receiving AM. Transmitting is disabled when they are in AM mode. There is at least one triple-band handy talkie that has the added capability of receiving both AM and CW. Now there are many choices.

The receiver is by far the most costly item in a radio tracking system. The directional receiving antenna, the cable and such, add a little to the cost, but these devices are never at risk (unless you drop the receiver on a sidewalk), so they should perform for many years. A club or group of users can own a receiver and antenna to spread out the cost, and a license is not required for receiving. The transmitter is the only item at risk (of being smashed to bits or lost in a lake), and by the way the T400 transmitters are encapsulated and waterproof.

The Icom IC-Q7A (left) looks just like the IC-R2 Communications Receiver shown in the group above. It is a dual-band transceiver (handy talkie), but it also can receive AM signals. The price in most stores is about $120.

The Yaesu VX-1R on the right is even smaller. It is a dual-band transceiver that also can receive AM signals. Its cost is about $130.

Both of the units shown here have an SMA antenna connector, not a BNC connector. So an SMA to BNC adapter connector is required if a BNC cable is to be used to connect to the tracking antenna.

The Kenwood TH-F6A is a triple-band transceiver that can also receive AM and CW signals. Cost is around $330. It has an SMA antenna connector.