Cactus Hack – P365 Jul16

The other day, the PC Synch cable which attaches the Cactus wireless flash trigger to my Canon 580EX flash broke. I’ve read on Strobist that PC Synch cable connectors are notoriously weak and unreliable. One clever member of the Strobist discussion group hacked their Cactus receiver to have an additional 3.5mm phono jack. So I decided to do the same!

Since hacking a 3.5mm phono jack to my 580EX, I’ve not needed to use the Cactus’ flimsy cold foot adapter, which I have since removed. That left me with the perfect location to put a 60 cent 3.5mm phono jack. I drilled out a slightly larger hole, pushing the drill bit to the side a bit to widen the hole in the direction away from the Cactus’ circuit board. I used a couple of layers of electrical tape to cover the contacts on the board near the hole to prevent accidental short circuit.

Before putting in the new jack, I soldered on the two short lengths of wire to the contacts, to save me from having to do that inside the cramped confines of the receiver. With the jack secured firmly in place, I cut the wires to length and stripped them. I dobbed some solder onto the ends of the wires to give them a little something to adhere to the places they would be attached.

The trickiest part of the job was bending the wires the right way and working in the tiny space of the receiver case to solder the wires to the appropriate points on the PC Synch port. After two hours of hunching over the soldering iron, I had two Cactus receivers, now with 3.5mm phono jacks, and two custom male-to-male 3.5mm phono cables to attach them to my flashes! And, at least with the 580EX, they work perfectly!

I was quite proud of my "leet hacking skilz".

Unfortunately the PC port wasn’t the only thing that broke the other day. For some reason, my Vivitar flash now won’t fire when triggered by the wireless receiver. I can’t figure out what’s wrong yet, various testing has eliminated the receivers, the flash hotfoot and the flash itself (fires on camera and with test button). It won’t fire via the PC Sync-Vivitar cable on the Cactus receiver. To me that sounds like either the Vivitar cable or the Vivitar port has failed.

I’m afraid that I might have to take the flash into a Vivitar dealer and see if I can get it fixed under warrantee – if I can find such a place in Melbourne. Failing that I might have to hack a 3.5mm port into the Vivitar as well, but that’s no guarantee to get it working!