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Assembly and Operating Instructions for Kits


Operating Instructions for the Multi-Trigger 2


Assembly instructions for other kits


MT2 assembled


Here is a printable version of this manual.




Sensor cables included with the MT2

Interrupter photogate cable

Photogate cable (SPG2 type)

Individual emitter and detector photogate cable

Photogate cable (SPG1 type)

Microphone cable

Microphone cable



Flash trigger cable

A flash trigger cable such as one of the three shown below is needed to connect the the outputs of the MT2 to a flash unit. The cables are purchased separately from the MT2. The connector for the control box is a 3.5mm mono plug. An adapter is provided with the flash trigger cable to convert 3.5mm to RCA when using the extended outputs of the MT2.


PC-type flash trigger cable

PC type

Flash shoe cable ready to connect to trigger box

Flash shoe type

Vivitar 283 type flash trigger cable

Vivitar 283/285/3700 type

Camera shutter cable

A shutter cable is required to actuate a camera using the MT2. The cables are purchased separately from the MT2.


Canon RS-60E3 shutter cable

Canon RS-60E3

Canon RS-80N3 shutter cable

Canon RS-80N3

Nikon MC-30 shutter cable

Nikon MC30

Nikon MC-DC2 shutter cable

Nikon MCDC2

RS-80N3 shutter cable

Sony S1



Refer to the following photo for the locations of the knobs, switches, jacks, and LEDs on the control box

MTE-PCB controls


Note: It's best to have the unit turned off when inserting plugs into the input jacks.


Powering the Multi-Trigger


AC-to-DC 9V adapterThe Multi-Trigger circuit is powered by 9V DC. This can be supplied either with a 9V battery or an AC-to-DC 9V adapter. The AC/DC jack on the enclosure accepts a standard 2.1mm plug such as the one on the adapter to the right. (Center pin is positive.) When the AC-to-DC adapter is plugged into the box, the battery is automatically disconnected internally.


In order to install or replace a battery, remove the four screws that hold the lid in place. Then lift the lid carefully so as not to stress the wires that connect the lid to the battery holder. If necessary, the battery holder itself can be removed, as it is held to the bottom of the box with hook and look tape. After replacing the battery, lower the lid on onto the box, being careful not to pinch any wires between the lid and the box. Then screw the lid back down.


When the on-off switch is flipped to the ON position, the LED next to the switch will light. If you're operating on battery power and the light is dim, that may indicate a weak battery. When the battery is weak, the unit may still function but demonstrate erratic behavior. That's a sign to replace the battery or use an AC-to-DC adapter.


The Delay Unit


In order to test the operation of the delay unit, first plug in the microphone cable. Then set this starting configuration:

  • Power switch ON
  • Input selector switch on MIC
  • DELAY/10 switch to OFF
  • TIMEOUT knob turned fully counterclockwise
  • All other knobs turned to their halfway positions
  1. Press and release the TEST button. You should see the TRIG LED light momentarily. This indicates that the delay unit triggered.
  2. Turn the COARSE DELAY all the way clockwise. Press the TEST button. You'll notice a longer delay before the trigger indicator lights. Turning the FINE DELAY clockwise also increase the delay. However, you're not likely to notice this visually, since the FINE DELAY control provides about 0.05s of delay at the most.
  3. Turn the TIMEOUT knob all the way clockwise and press TEST. TheTRIG LED will remain lit for about a second. During this period of time, the delayed output of the delay unit is inactivated. When using a flash, setting a long timeout prevents multiple exposures. This comes in most useful when using the sound trigger. Loud sounds that last for a while or that produce echoes can set off the sound trigger repeatedly. Setting a long timeout provides time for the sound to decay before the flash can discharge a second time. When triggering a camera, a long timeout prevents the shutter from actuating repeatedly.
  4. Turn the TIMEOUT back to the original position, and flip the DELAY/10 to the ON position. When you press the TEST button, there will be no noticeable delay even with the COARSE DELAY turned all the way clockwise. This is because all delays are divided by 10 from the original position. This is useful when you need particularly fine control of the delay for events for which the maximum delay needed is less than about 0.05s.
  5. Now flip DELAY/10 to the OFF position. Using the appropriate trigger cable for your flash unit, connect the FLASH DELAYED output jack to your flash unit. Turn on your flash. When you run a finger through the photogate or push the TEST button, the flash should discharge.

The Photogate


With the unit turned off, insert the 3.5mm plug of the interrupter (SPG2) photogate cable into the PG jack. Be sure to push the plug in all the way; otherwise, the photogate won't work. Flip the input selector to PG and make sure the PG SENS knob is turned to its halfway position. Turn the unit on. The PG LED on the right side of the panel should light as soon as you turn on the unit. This LED indicates that the photogate beam is unbroken. Now run a finger through the interrupter. The alignment indicator will go out, and the TRIG LED will momentarily light and the flash unit discharge after whatever delay you've dialed in.


Now turn off the unit, remove the interrupter photogate cable, and insert the other photogate cable (SPG1). Tape the emitter and detector to the table pointed at each other a few inches apart. Turn on the unit. The PG LED should come on. If it doesn't, check the alignment of the emitter and detector. If you wish, move one of them to the side to verify that the PG LED responds correctly. Now turn the PG SENS knob clockwise until the alignment LED goes out. This happens when the sensitivity is set too high. In order to set the sensitivity at the highest it can be without going over the threshold, dial the knob back to the point where the LED comes back on. If you're running on battery power, the sensitivity may drift as the battery runs down. So if you have the sensitivity adjusted to the threshold, you may have to readjust it as the battery weakens. You also need to readjust the sensitivity when you change the separation of the emitter and detector. Whenever you position the emitter and detector for an experiment, be sure to anchor them as rigidly in place as possible in order to maintain alignment as well as the sensitivity adjustment.


The Sound Trigger


Plug the microphone cable into the MIC jack and flip the input selector to MIC. Turn the SND SENS knob to the halfway position and turn the TIMEOUT all the way clockwise. Turn on the unit. Snap your fingers or tap the microphone. The TRIG LED should light and the flash discharge the same as in your tests of the delay unit and photogate. With the TIMEOUT set to 1s, the flash will remain inactive for about a second. This is the typical TIMEOUT setting to use with the sound trigger in order to avoid multiple images from repeated triggering of a flash. Of couse, you may use a smaller TIMEOUT if you wish. In order to increase the sensitivity of the sound trigger, turn the SND SENS knob clockwise.


The External Input


The external input jack can be used to connect other triggers to the delay unit. When a 3.5mm mono plug is inserted into EXT IN, both the photogate and sound trigger circuits are internally disconnected from the delay unit. You can connect as an external input any trigger that produces a short circuit as an output. An example is a simple contact trigger. In order to use this input, you'll need to prepare a cable from your trigger output to the external input. Note that the external input jack on the MT2 uses a 3.5mm mono connector. (Parts for an external intput cable aren't included with the MT2.)


The Instant and Delayed Outputs


Important: If your flash unit has a high-voltage trigger circuit (greater than 80V), don't connect it to the outputs on the lid. Modern flash units typically have low-voltage trigger circuits but older units may have voltages of 200-300V. For example, Vivitar 283 units manufactured before 1984 have high-voltage trigger circuits. Vivitar 283s manufactured after that date have low-voltage trigger circuits. You'll know if your flash unit has a high-voltage trigger circuit, because it will sting you if you touch the output terminals. If you want to trigger a high-voltage unit with the Multi-Trigger, you'll need the Output Extender Kit. By the way, if you do use a high-voltage flash with an output on the lid, you'll burn out an optocoupler and possibly also the 556 timer. These chips are inexpensive and easily replaced.


Aside from the restriction noted above, you can trigger flash units, camera shutters, and wireless transmitters from either the INSTANT or DELAYED output. For a flash unit, connect a trigger cable between the output jack and the flash. You may need to use the 3.5mm to RCA adapter depending on the type of connector that you have on your trigger cable. Note that the position of the REVIEW/FOCUS switch is unimportant when using a flash unit. Now, when you trigger the delay unit either with the TEST button, photogate, or microphone, the flash should discharge. If you are triggering your flash through a hot shoe, note that some flash units (examples are the Nikon SB600 and the Canon 430 EXII) must be put in manual mode in order to trigger them through a hot shoe.


For triggering a camera shutter, use your camera shutter cable to connect the camera to an output. Set your camera for manual operation (focus and exposure). Depending on your camera, it may or may not be necessary to flip the REVIEW/FOCUS switch to the FOCUS position in order to be able to trigger the camera. The REVIEW/FOCUS switches perform the shutter half-press operations of your camera. Some camera makes such as Nikons require that the half-press operations be performed before the shutter can be actuated. Other camera makes such as Canons do not have this requirement, so the position of the REVIEW/FOCUS switch may be unimportant for such cameras. Note also that for Nikon camera, the REVIEW/FOCUS switch must be in the REVIEW position in order to view images on the camera's LCD.


Using the Extended Outputs


If the control box has the extended output strip on the side, here's what the extra 4 outputs are for and how to use them.


  • I means INSTANT and D means DELAYED. These outputs are triggered at the same time as the INSTANT and DELAYED outputs on the top of the box.
  • S means SWITCH and V means VOLTAGE.


The SWITCH outputs can be used to trigger flash units that have high-voltage trigger circuits (up to 400 V).


The VOLTAGE outputs provide low-current pulses of about 7.5V. The instant pulse is very short. The delayed pulse lasts for the same amount of time as the TIMEOUT LED is lit. Here are some examples of ways the VOLTAGE outputs can be used:

  • triggering a flash unit that requires a low voltage pulse. Some studio units have such a requirement.

  • triggering a Camera Opto-Switch. Of course, you already have camera-enabled outputs on the lid. But maybe you have an application where you want to trigger two cameras at the same time.

The extended outputs are of the RCA type. If your flash trigger cable has a 3.5mm plug, you'll need an adapter to convert to RCA.




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