KK_20070520_161651_mkfair07, originally uploaded by kenji.kato.

Kenji Kato visited the Quaketronics booth at the 2007 Bay Area Maker Faire. He brought his Nikon 10.5mm fisheye lens and Kenji took more great pictures which he uploaded to flickr.

XenonFlashTubes, originally uploaded by Quaketronics Tom.

I tried kalimistuk’s technique for speeding up his strobe light. Kalimistuk modified the UK equivalent of the SnapShotII. He replaced the flash tube with a smaller tube to speed up the flash. I used a Radio Shack 272-1145 Xenon Strobe Tube, which is available for $4.75 from www.radioshack.com. I made some measurements and found that I also got a speedup.

This simple modification sped up my SnapShotII from a flash duration of about 70uS to about 40uS. That is equivalent to a speedup from 1/14,000 of a second to 1/25,000 of a second. The new tube turns off more quickly, which will help reduce the high-speed smearing even more.

The SnapShotII has a clear plastic cover on the end. This cover protects the bulb and probably also acts as a UV filter, blocking out the UV light that a bare xenon strobe tube produces.

The cover comes off easily. The bulb pulls out of a socket at the bottom of the reflector. Unplug the strobe first! After unplugging, wait at least 72 seconds before replacing the tube. This allows enough time for the high-voltage capacitors inside the SnapShotII to discharge to a safe voltage. Replace the cover after changing the flash tube.

The pins for this socket are the same as the pins used in an 8-pin vacuum tube. My junk box has plenty of old tubes, so I sacrificed one to get some pins. I soldered a Radio Shack 272-1145 Xenon Strobe Tube ($4.29 at www.radioshack.com) to three pins. The result is shown in the picture above. The original tube is on the left and my replacement tube is on the right. I plugged the replacement tube into the SnapShotII and measured the optical output with a photodiode and an oscilloscope.

This new tube does gets a hotter than the larger tube in the SnapShotII. This shouldn’t be a problem as long as you don’t run the strobe at too fast a flash repetition rate. At a high flash rate of many flashes per second, the tube may melt the solder joints, or I suppose something could potentially catch fire, which would be very bad! This overheating problem is worse with smaller tubes. In my first attempt I melted a small tube from a disposable camera! Be careful!

The Quaketronics flash controller can control a Snap Shot II strobe light. This strobe is faster than the flash that comes in the Quaketronics kit. I measured the duration of both flashes. The SnapshotII provides a flash about 1/8300 of a second, and the flash in the kit provides a flash of about 1/1700 of a second.

Similar strobes (except for 220V operation) are sold under different names in the UK. Look for the familiar shape, and two 6.32mm connectors (that fits a 1/4″ guitar cable) in the back.

Sometimes you can get a lower price on these strobes - today the price is low at amazon.com. I ordered a spare so that I can try the modification suggested by Kalimistuk: use a smaller flash tube. The Snap Shot II strobe is also available at musiciansfriend.com and other online suppliers.