Detailed Cactus V2s Mod Page

The slickly named "Cactus V2s" wireless triggers have become the staple entry point remote for those with more enthusiasm than cash.

Now you can prolong your "I'll never cough up for Pocket Wizards" fantasy just a little longer, as blogger/tightwad Jeremy Kuster has posted the most comprehensive Poverty Wizard mod tutorial to date.

More pix, links after the jump.

Jeremy posts pix, detailed instructions and an online source for the toughest part (the xmit antenna is store-bought -- and cheap) and assumes you have access to a RatShack or equivalent for battery holders, etc.

(If not, you can get that stuff the same place he sends you for the antenna.)

Don't get me wrong. If I were in college I would totally be on this route. But if you are in the game to stay, you will eventually be drinking the Pocket Wizard Kool-Aid just like everyone else.

(I'm just saying.)

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:: Cactus V2 Product Page ::


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Blogger kuster said...

As much as I'd love to drink the PW kool-aid...;-)

I just wanted to make them as reliable as I could and keep them looking semi-professional. Until I'm have the money to spend on PW's anyway.

And for what it's worth, I'm out of college, but I'll be paying for it for the next 10-15 years... So ebay triggers it is for me :-D

October 30, 2007 10:08 AM  
Anonymous Dewey said...

Well, at this point even if I want to shell out $800US for remote triggers I'll wait to see what RadioPopper comes up with. On the one hand, it's too good to be true. On the other, it's (allegedly) only a few months away.

It would be nice if the Kool-Aid had some competition.

So far, my Poverty Wizzards are in the category of "amazingly well worth the money" in that they're doing *just* fine for the ranges I use them (~50' around very few corners). Maybe as my usage advances I'll run in to issues but for now $800 would go better towards nice glass that I've been itching for...

October 30, 2007 10:26 AM  
Anonymous Spica said...

Yes ! That's just what I waited for !

October 30, 2007 10:48 AM  
Anonymous Eric said...

Thanks for the resource. Quality info as usual.

October 30, 2007 10:53 AM  
Blogger Jacob said...

I posted this in Kusters blog as well, but figured I'd cross-post here too.

Here is a link to my modification of the V2's - soaking the PC in epoxy as a backup, but more importantly, adding a 1/8" plug connection. This will be even easier if you choose to do his battery modification, as it will give you much more room in the casing to work. Scroll about halfway down past my rants to get to the fix.

October 30, 2007 11:27 AM  
Anonymous dack said...

There's a couple of problems with the transmit antenna mod shown. You should cut the antenna trace on the circuit board so that it does not affect the impedance matching. You should also connect the outer part of the SMA connector to the analog ground on the circuit board in order to create a better ground plane.

October 30, 2007 11:39 AM  
Blogger marko said...

Any idea if mounting the antenna to the receivers would also help with the reliability and range? It seems like a good idea on the transmitter, but why not the receiver as well?

October 30, 2007 11:53 AM  
Anonymous Anonymous said...

I'm pretty sure the antenna modification is illegal in the US. I'd check FCC regs.

October 30, 2007 12:09 PM  
Blogger xtaylorxcorex said...

i think buying pocket wizards is the wisest investment a strobist can make, i've had mine for about a month and the level of frustration at my shoots has nearly disappeared. they arent THAT expensive.

October 30, 2007 1:26 PM  
Anonymous Anonymous said...

'course it's illegal! Since when have we strobists been known to follow the law....?

October 30, 2007 1:29 PM  
Anonymous scott said...

I recently upgraded from my GIs to Skyports and I've only had a chance to use them once, but so far (all of my tests -- walking as far away as I can in the house :) they're better than the old and cheaper than PWs.

Doesn't that count as Kool-Aid competition?

October 30, 2007 1:36 PM  
Anonymous Anonymous said...

"Im pretty sure the antenna modification is illegal in the US. I'd check FCC regs."

I tore a tag off of a mattress once and a while back I threw a dead flashlight battery in the trash.

I guess I'm addicted to the spice of danger.

October 30, 2007 2:11 PM  
Anonymous chs said...

I honestly don't think I'd ever be able to justify the cost of the pocket wizards. They are just too expensive and bulky. I don't get paid for my photography, and I'm not planning on getting paid for my photography. So I just won't ever buy PW's.

Now, the elinchrom skyports I can justify. Until then, I love this mod!

There's nothing too wrong with the ebay triggers that can't be fixed yourself with very little time. The antenna mod is a great one.

To the person who recomended cutting the trace and grounding the antenna, would it be enough to just connect ground to the negative battery terminal (as well as cutting the trace, obviously)?

October 30, 2007 3:58 PM  
Anonymous Stephmw said...

As far as I understand it, it's just the transmitter you're not allowed to modify (oh dear)...

So if that holds, you can do pretty much anything to the receiver to increase its sensitivity.

October 30, 2007 4:30 PM  
Blogger D2 said...

I own Pocket Wizard Plus II's...,.but during the Georgia Strobist meet I found my Cactus V'2's to be more efficient because fewer people had them so I didn't have to worry about my flash popping off because of the limited 4 channels of the Plus II's.

We also found that infared was a pretty good trigger as well..... for the circumstances of a big meet in which everyone has four channel Plus II's.

October 30, 2007 5:36 PM  
Anonymous Chris said...

There have been some murmurings about modifying Cactus' and the Poverty Wizards for use with a low sync voltage flash.

Does anyone have any more info on that modification?

October 30, 2007 7:06 PM  
Blogger KJM said...

Just go ahead, and buy the PW's. I did, it broke the bank, but the reliability, and the peace of mind of a system that works well everytime: Priceless:)

October 31, 2007 8:35 AM  
Blogger scubajunkie said...

Regarding FCC regs, I don't think adding an antenna alters FCC approval. Hams buy or build better antennas for their transmitters all the time, even the handheld transmitters. Increasing the power output of the transmitter most certainly would alter FCC approval.

Also, Digi-key is now out of both the antenna and bulkhead connector (they had over 300 antennas yesterday). I guess a lot of people want to mod their poverty wizards.

You can accomplish much of the same results with a 6.5" wire (1/4 wave) or 3.25" wire (1/8 wave). I tried this last night and I can reliably trigger my flashes located at one end of the house on the main floor from the other end of the house upstairs. YMMV

November 01, 2007 10:52 AM  
Blogger kuster said...

If Digi-Key is out, you can buy directly from Linx Technologies (, they actually supply digi-key with the antenna and connector both. Just thought I'd let y'all know, I posted it a few other places as well to try and get the word out.

November 01, 2007 12:11 PM  
Anonymous Anonymous said...

hopefully I can add to the whole ebay mod pool with modifications:

- Bon C

November 05, 2007 11:31 AM  
Blogger Noah said...

I'm not sure that you do need to cut the trace of the antenna on the circuit board.

I believe back in '96 when I was studying to get my Amateur Radio License that I read that there are HF setups that are directly connected to an array of different antennas, and the operator didn't have to switch to a different antenna when they changed frequency bands because the signal would pick the path of least resistance, which was the antenna that it was closest tuned to.

I do think I'll see if I can get a short length of shielded wire to connect the board to the antenna so it won't radiate from there, (although, I wonder if a little Aluminum Tape wrapped around the plastic sheath of the wire and connected to Ground and then wrapped in electrical tape would work...), as well as connect the body of the SMA connector to the negative pole of the battery connector to create a ground plane.

November 20, 2007 10:03 AM  
Blogger semigloss said...

Hey guys I bought 3 receivers and one transimtter from ebay. its the version that works with 580exII. Anyways it does work on the 580exII and the vivitar 283. But it wont fire my 3 vivitar 850 afc. the trigger voltage on the vivitar850 flash is 4.6volts. Can someone help me?

December 06, 2007 12:41 AM  
Blogger Noah said...

I just noticed that DigiKey now has both the antennas and SMA connectors back in stock, and I just placed my order.

I actually also picked up a few "ANT-433-CW-RAH-ND" right-hand antennas for the receivers. They may only be 1.8 inches long, but considering they have 6.5" of wire wound to form a 1/4-wave antenna, it should provide for better signal gain than what they come with...

I'm hoping that with a 1/4-wave antenna on both the transmitter and receiver, this should be a failrly reliable solution for us non-Pro photos who love their gadgets, (and are too cheap to pony up for the "Kool-Aid").

December 18, 2007 11:22 AM  
Blogger Brad Shearer said...

Based on this I modified my triggers today, and I created a little video of it here

April 09, 2008 5:40 PM  
Blogger strobe monkey said...

I have made a 1/2 wavelength coiled wire antenna.
Blogged it here:

April 21, 2008 7:15 PM  
Blogger strobe monkey said...

Heres is my own 1/2 wavelenght coiled copper wire antenna mod:

April 21, 2008 7:24 PM  
Anonymous Anonymous said...

Instead of modding the cactus, are there any requirements (outside of reliability) that should be in an affordable started unit? I have an electrical design ready to go to remotely trigger flashes. Triggering will be as reliable as the PW, except the design uses a cheaper architecture, especially for manual mode remote flashing. (or should I start this somewhere else?)

April 28, 2008 9:08 PM  
Blogger Patrick said...

I'm looking to hardwire a few of these to some flashes I have through the PC out. I've done this with the units labeled "PT-04 Receiver" but they ones labeled "Cactus PT-04" and "Cactus V2s" do not have enough voltage to trigger the flashes.

Does anyone know a mod I can do to increase the voltage or know which ones to buy that will fire my flashes?

May 02, 2008 10:02 PM  
Blogger Bertrik said...

I reverse engineered the protocol of the 433 MHz signal that the cactus sends. It's basically 20 identical sequences of 6 pulses each. It should be easy to reproduce these with a tiny microcontroller and a cheap 433 MHz AM module. Interesting observations so far:
* the 4 channels all transmit on the same frequency, but with a different code for each channel.
* not all codes take the same time to transmit, from about 1.3ms (ON-ON) to 2.0 ms (OFF-OFF).
I plan to put more information on my webpage soon(-ish).

April 15, 2009 12:57 PM  

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