Post your ebay trigger mods here..... Lets build a list for everyone to use.
Who you bought your trigger from, model type, price if you want, type of modification, and your results, any parts used, where you got the parts, any links to mods, good or bad results, anything pertinent for all of us.....
I think this will be GREAT for all of us on a limited budget but still want to get the job done.
I have a couple of 4 channel AC Ebay triggers. To double the effective range, I plug a receiver into a transmitter mid-way between the camera and the lights. The only drawback is that you should shoot slower to make sure the shutter is open when the two triggers fire.
louhand wrote:
I have a couple of 4 channel AC Ebay triggers. To double the effective range, I plug a receiver into a transmitter mid-way between the camera and the lights. The only drawback is that you should shoot slower to make sure the shutter is open when the two triggers fire.
That would be a great way to test how fast they are. Set up a fast-moving subject (that moves at a known speed) and use two flashes. One on the first receiver and one on the second receiver. Then check how far the target moved between the flashes.
I have about four of these things. I wonder how far I could stretch the range if I installed an extended antenna on all of them.
Uusilehto wrote:
That would be a great way to test how fast they are. Set up a fast-moving subject (that moves at a known speed) and use two flashes. One on the first receiver and one on the second receiver. Then check how far the target moved between the flashes.
I have about four of these things. I wonder how far I could stretch the range if I installed an extended antenna on all of them.
Based on how fast your flash discharges, you should be able to determine the ideal shutter speed for tandem triggers. That is, if you detect a loss of light or no light at all, just increase the time on your shutter speed until no change is detected.
Theortically, without antenna modifications, you should get approximately 100 feet, with clear line-of-site, from each transmitter to each receiver for a total of 400 feet range. If you only have 4 units, you will have one light triggered at the end of the 400 foot range, unless you can optically trigger the rest of your lights in your set up.
Here's my mod using bits from a A$2 night light purchased at a discount store that allowed a plastic sleeved aerial, of the right length for the GI V.2 Cactus Tx's frequency, to be simply screwed onto the PCB. No soldering required.
From 12.5 metres of range to 75 metres, without mis-fires, triggering a 580EX and a 580EX II, in just 10 minutes. All it needs is some coiling of the the aerial to prevent me taking an eye out.
This ought to give me something to play around with until I can make my mind up as to whether to purchase PWs or Skyports.
AngusM great mod.... What is the length of the aerial? What did you do to determine the length for this frequency? Thanks for the pictures, this will help other FMers with their transmitters. Does anyone have a chart or program for determining the length of an aerial at most frequencies? Please post if you do... Lets keep this thread going....
Ron
Ron Beezley wrote:
What is the length of the aerial?
Approx 6.2 inches (15.74cm) currently.
Ron Beezley wrote:
What did you do to determine the length for this frequency?
The correct length for an antenna is, according to other modification info on sites like Flickr etc, 1/4 the wave frequency, which means nothing to me and I can't see how the above figure relates to this. But.. I read that someone had success with an antenna length of 6.1 inches (another had success with 5.57 as well, some smaller again) so I started slightly longer with the intention of trimming until I got the desired range improvement. I got 75m, which is about all I need, untrimmed so the length remains.
Nothing scientific sorry as I have limit electronics knowledge. Nor I am skilled with a soldering iron which is why I went for a 'screw in' antenna. It's reversible and there is no risk of cooking the PCB or other components with dodgey soldering.
I have only just got these GI Cactus's to play around with but will do a bit more work on the antenna in the next few days to see if I can reduce the length without losing range or, in the least, coil or fold the antenna so it is more compact. If I could get the same distance and zero misfires with a less long antenna that would be ideal.
You might try coiling about 2/3rds of the antenna around like a 1/2" dowel and trying that and leave an equal space between the coils. You might want to try, http://www.aarl.org for insite on your antenna mods. My brother is a ham
radio operator and he's successfully built antennas for years and he learned most of his stuff from this site.
The correct length for an antenna is, according to other modification info on sites like Flickr etc, 1/4 the wave frequency, which means nothing to me and I can't see how the above figure relates to this. But.. I read that someone had success with an antenna length of 6.1 inches (another had success with 5.57 as well, some smaller again) so I started slightly longer with the intention of trimming until I got the desired range improvement. I got 75m, which is about all I need, untrimmed so the length remains.
Nothing scientific sorry as I have limit electronics knowledge. Nor I am skilled with a soldering iron which is why I went for a 'screw in' antenna. It's reversible and there is no risk of cooking the PCB or other components with dodgey soldering.
I have only just got these GI Cactus's to play around with but will do a bit more work on the antenna in the next few days to see if I can reduce the length without losing range or, in the least, coil or fold the antenna so it is more compact. If I could get the same distance and zero misfires with a less long antenna that would be ideal.
In a perfect world we'd use an antenna that would be the same as the wavelength used by the transmitter. Which happens to be 69.24cm (the speed of light/433x10^6hz)convert that to inches, divide by 4 and you get 6.81in. The idea is to create resonance. If the wave resonates in the antenna it works better.
I'm sure there are other factors like the "quality" of these units that account for the difference in antenna length. Then again some people solder new antennas on and the triggers practically stop working.
I did this mod and forget what length I used but it works great! The thing goes through walls even. Mine didn't even have a dinky little antenna like you see in pictures; just had a hole in the board where the antenna should have been.
Feel free to correct me on any of this. I'm not an expert, just a college student sharing some stuff I learned in physics.
I have just spent an hour playing around with my Cactus mod. and with the antenna altered (coiled clock-wise, and anti-clockwise, loose coil and tight as well as folded even) the range reduced to that of no antenna at all ie. about 12m without misfire. Re-straightening it saw the range return to 75m without misfire again and with 30 flashes to prove it.
Thankfully my Elinchrom Skyports aren't too far away and I can soon get on with taking photos without the inept science experiments. But until they arrive I am pretty happy knowing what I can get from the GI units when I need the extra range (and the Canon wireless option for it's sheer ease of use but at a reduced range) with a bit of very basic modification. Given how simple it has been I am pretty impressed at what these cheap slaves can do; albeit in a 'you get what you pay for' way.
It seems silly and simple, but the best thing I've ever done to my V1 ebay triggers was take the metal foot off, tape over the opening with gaffers tape and stick some velcro to the side of the trigger and the sides of my flashes and studio light. It's so much easier to keep track of everything when it's all velcroed together! I've also been contemplating this mod:
looking through the flickr strobist discussion boards i have see things about where you attach the antenna/aerial. Once its opened up there is the small hole and then the larger hole, i have seen mods on both holes. does it make a diff?
i also saw somewhere people saying that for V2 you have to do the smaller hole or else it wont work......?
Leave the top off and try each hole and see which one works for the trigger you have... They might have a trace circuit that goes to both holes in which hole you use would not make a difference. The trace circuit is a small copper strip that goes around one if not both of the holes.
Ron
Try a 6" piece of 12 guage stiff wire. Leave the insulation on it except for maybe 1/2" on one end. If you have room to put it, put a small screw and nut in the hole. make a small loop on the end of the wire and slide it under the screw head to secure it. Good for testing!!! make SURE not to short any thing else out when you put the screw in.....
Email me some pictures of your setup and I'll help you out... I have over 30 years in electronics. mailto:[email protected]
Ron
zepper7 wrote:
It seems silly and simple, but the best thing I've ever done to my V1 ebay triggers was take the metal foot off, tape over the opening with gaffers tape and stick some velcro to the side of the trigger and the sides of my flashes and studio light. It's so much easier to keep track of everything when it's all velcroed together!
Ron Beezley wrote:
Try a 6" piece of 12 guage stiff wire. Leave the insulation on it except for maybe 1/2" on one end. If you have room to put it, put a small screw and nut in the hole. make a small loop on the end of the wire and slide it under the screw head to secure it. Good for testing!!! make SURE not to short any thing else out when you put the screw in.....
A strobe mounted on the Cactus trigger works but is very unstable and flimsy looking. I attempted to make a simple wooden block mount using a separate hotshoe adapter. Turns out that I used the cheap "General Brand" hotshoe adapter that is described as a problem in one of the sticky notes in this forum. The hotshoe did not break but the trigger does not fire the strobe through the hotshoe. I've checked and the hotshoe is electrically OK and even fires a simple (old) strobe from a simple (old) camera. But the General Brand hotshoe won't fire a strobe when connected to the Cactus trigger. I checked several strobes (Nikon, Canon, Vivitar) and two hotshoes. Doesn't work.
