Adept Rocketry - SB1 Instructions and Data Sheet

Small Sonic Location Beacon™ (Beeper)

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SB1 Small Sonic Location Beacon™ Price: $19.95 - Includes GP-23A Battery.


The Model SB1 Sonic Location Beacon™ is a very small audible beeping device that may be used to help locate model rockets, model airplanes, payload carrying balloons, and so on. This device creates repeating 4000 Hz patterned beep tones (double beeps) at a volume of 90 decibels. The device has a mute system that may be used to silence the beacon until takeoff, or until deployment of the parachute. In the silenced mode, the beacon will run for a week on a fresh battery, which means that you need not be concerned about how long the rocket sits on the launch pad. When beeping, the battery life is in excess of 24 hours, so you'll have plenty of time to look for a lost rocket or payload.

With some designs it is common to use more than one sonic beacon in the same rocket. Many rockets are designed to separate into two or more sections for recovery, such as with a system that normally ejects a payload which has its own parachute. A second sonic beacon can be included with the payload section.

The SB1 measures 0.55" wide by 0.60" thick by 2" long. Its weight with battery installed is only 0.42 ounce (12 grams), and it fits inside a tube with a minimum ID of 0.68 inch (17.3 mm), a loose fit in an Estes BT-20 body tube. This device runs on a 12-volt alkaline lighter battery. It will operate mounted in any orientation, and it can be heard from a distance of over 50 yards.


Install a 12-volt alkaline lighter battery (GP-23A, Eveready Energizer No. A23, Radio Shack 23-144, etc.) in the battery holder. The beacon will start operating. To reduce the sound while testing, hold a finger over the sound port, or temporarily use a small piece of tape or reusable putty. Remove the battery when not in use to avoid prolonged stress on the battery holder and possible long-term disfigurement of the battery holder.

The SB1 is equipped with two protruding wires that function as a 2-pin slip connector. This allows the unit to be put into a muted standby mode when a shorting jumper is installed on the two pins. Slip a shorting jumper onto the two wire connector pins to put the device in standby. This will mute the sound, and the current consumption drops substantially. A string is tied to the shorting jumper, and when the string is pulled, the shorting jumper pulls free and allows the beacon to start beeping. As shown above, the same string that connects to the beeper may also be rigged to pull free the jumper as soon as there is tension on the string.

When the jumper is pulled free, the unit goes into operational mode. The jumper can be pulled free with a string that pulls when the rocket separates, or by deployment of the parachute. Some other options for activating the device are:

  • A small weight could pull the jumper free on the first acceleration of liftoff.
  • A small shorting switch could be wired to the connector, and when the switch opens, the beacon would start operating. The switch could be held closed by contact with the launch rod, or the switch could be held closed until stage or section separation.

If you do not wish to use the mute system (the SB1 is not uncomfortably loud when inside a sealed rocket), then you need not do anything with the jumper. The beacon may be beeping when it is installed and before launch if you don't mind the noise.


  • Dimensions: 0.55" wide by 0.60" thick by 2" long. It fits inside a tube with a minimum diameter of 0.68 inch (17.3 mm), a loose fit in an Estes BT-20 body tube.
  • Weight: 0.42 ounce (12 grams) with battery installed.
  • Sound Level (measured at 12 inches): 90 db typical.
  • Beep Tone Frequency: 4 kHz nominal. Pattern: 2 quick beeps every 2.5 seconds.
  • Operational Current Consumption: 1 mA nominal. Standby Current Consumption: 0.1 mA nominal.
  • Operational Battery Life: one day minimum. Standby Battery Life: one week typical.


This device may be mounted in any orientation. Small holes in two corners of the circuit board allow the device to be secured with string or wire. A shorting jumper (for muting) installs onto the 2-pin connector formed with wires. A weight connected to the jumper could pull it free on rocket takeoff. Or a string connected to the jumper could pull it free on parachute deployment, or when stages or sections separate. The picture above shows one handy way to rig the string on the beeper. There are numerous other ways to rig the device. You may wish to use a double string or loop that attaches to both of the holes, or you may wish to use some other complicated or innovative method. But in any case, be sure to use string that is strong, such as Kevlar.

This device fits inside a tube with a minimum ID of 0.68 inch. It may be mounted and secured inside a short section of tube of its own for protection (and so the circuit board won't snag on anything), then the entire beeper/tube assembly can be ejected along with the parachute. Just connect the assembly to an appropriate point on the shock cord or parachute line, or it may have its own section of shock cord which is connected to the parachute system.

In the picture sequence above, the beeper is friction fitted inside a two-inch length section of BT-20 body tube. A two-inch square piece of paper towel, one or two layers thick, is folded over the end of the beeper, and then the beeper is pushed into the tube. Be careful to stay clear of the muting jumper gimmick. The friction fit will hold the tube in place to protect the beeper from a mud landing or whatever. The tube over the beeper will not reduce the sound volume.

If the SB1 is to be used in a small diameter tube such as a BT-20, then obviously there is no room to install the unit in a tube of its own as shown above. Slip the beeper into the rocket last, just below the nosecone, and above the parachute and wadding.

In any case, no matter how the device is installed, always be careful to have lots of parachute or wadding between the beeper and the explosive ejection charge. The residue created by burning or exploding gunpowder is very dirty and loaded with carbon, and it is electrically conductive. Use the same care with any electronic device that fits inside a rocket.

Unlike with the larger beepers, the SB1 is too small to allow mounting with screws and standoffs. Instead, two holes are provided on one end of the circuit board to allow securing the device with string or wire. The holes can also be used as tie points for the parachute cord or shock cord. The beacon can be secured in the base of the nosecone, or in the top section of the rocket near the separation point. In any case, if secured inside the rocket, it must be located near an opening to the outside for loudest sound. In some cases it's even possible to amplify the sound by adjusting the mounting position and letting the tube act as a sound chamber.

The beacon may be secured to basswood or plywood pieces that are connected to bulkheads or other structural components. In larger diameter rocket tubes the device can be mounted in a smaller section of tube (that has a sealed bottom) and secured in the parachute area of the larger tube. The parachute (and wadding if any) would fit into the remaining area beside the beacon's mounting tube. Care must be taken to assure that the parachute (and wadding) will still deploy properly. Note: the higher the device is mounted in the vehicle (CG closer to nose end) the more it adds to overall vehicle stability.


Adept Rocketry and Adept Instruments, Inc. warrant to the original purchaser that this product is free of defective parts and workmanship and that it will remain in good working order for a period of 90 days from the date of original purchase. This product will be repaired or replaced within 90 days of purchase if it fails to operate as specified, if returned by the original purchaser and if it has not been damaged or modified, or serviced by anyone other than the manufacturer. Adept Rocketry and Adept Instruments, Inc., their owners, employees, vendors and contractors shall not be liable for any special, incidental, or consequential damages or for loss, damage or expense directly or indirectly arising from customer’s or anyone’s use of or inability to use this device either separately or in combination with other equipment, or for personal injury or loss or destruction of other property, for experiment failure, or for any other cause. This device is sold as an experimental accessory only, and due to the nature of experimental carriers such as rockets, the possibility of failure can never be totally removed. It is up to the user, the experimenter, to use good judgment and safe design practices and to properly pretest the device for its intended performance in the intended vehicle, or reasonable facsimile of same, under controlled conditions to gain reasonable belief that the device and vehicle will perform in a safe manner, and to assure that all reasonable precautions are exercised to prevent injury or damage to anyone or anything.

WARNING: Do not use this device unless you completely understand and agree with all the above statements and conditions.

SB1 Small Sonic Location Beacon™ Price: $19.95 - Includes GP-23A Battery.

Additional GP-23A Alkaline Lighter Battery; Price: $2.25.

GP-23A50 Alkaline Lighter Batteries (box of 50 at 50% Discount); Price: $56.25.  3/20/11