RadioPopper JrX Cube – DIY

UPDATE:  New posting on the release of the official Radiopopper RPCube and a Canon DIY cube is here:

I’m a big fan of the RadioPopper guys.  I really think they are the real competition for the guys at PocketWizard.  The RP guys have had their share of delays, sputters, and poor public relations – at least from where I sit.  I suppose that sort of thing happens when a new company that’s new to manufacturing starts up.  I will say though that they have held to the highest standards.  Many start-ups would have felt the pressure to get something out on the street but they held fast and waited until they could deliver a high quality product.  They’ve scored again with the JrX Studio receiver.  The JrX is an amazing receiver with great range and reliability but the standout feature is the ability to control Alien Bee studio strobe power from the transmitter.  This is a feature of the RadioPopper PX transmitter too but the PX is more complicated to use and is more tuned to TTL flashes.

Quite likely the best feature of the JrX studio is it’s ability to control the power of TTL flashes from the trigger.  There’s only one catch, you need something called a “RadioPopper Cube”.  The cube will allow the trigger to send a “quench” signal to the flash and shutdown the flash power after an adjustable period of time.  The quicker the flash power is quenched the lower the power of the flash.  Don’t quench it at all and you’ve get a full power flash.

TTL flashes have a quench pen that allows flash to receive the quench signal.  Standard manual flashes don’t have the quench pin or the ability to be quenched – they’re just fire and forget.

Now as cool as all this is, there is bad news.  You need a RP Cube to connect to the RP JrX Studio to get the trigger/quench signal and pass it to the flash.  The bad news is that once again the guys at RP have not met their planned date to make the cubes available.    They were expected to be available 6 weeks after the JrX was made available but that time has come and gone.

20091105-215812
As received from BH Photo

The good news is that for Nikon TTL flash users at least, you can make you’re own RP Cube equivalent (or even maybe two) for about $15.  The photographers over at the Strobist.com Flickr discussion group figured out how to do it.  I read what they had to say,  made my own, and took pictures along the way so you can make your own too.

First you need to get a connector with the proper quench pin.  The Nikon AS-E900 (I got mine  here at BH Photo for $9.95) is a intended to be used with the Nikon Coolpix 900, 950, 990 or 995 digital cameras for use with a more powerful, external shoe mount flash.  We’re going to cut it up and make it work with the RadioPopper JrX.

In addition to the AS-E900 you’ll need at least one 1/8 (3.5mm) stereo plug from Radio Shack.  The only one my local Radio Shack was this two pack for $3.99.

This is the AS-E900 out of the box.  20091105-215914-Edit-3Note the hot shoe and the three pin connector on the other end.  We’re interested in the shoe end for now but after we cut the cable in half don’t throw away the three pin end.  You might be able to use it depending on what other flash you have.


The first step is to cut your AS-E900 cable in half like this.



Cut the cable in the middle
Cut the cable in the middle

Next you need to cut the cover off the cable.

20091105-221845

After you remove the cover you need to separate four components inside.  There is a braid of small uninsulated wires that are used for the ground.  There are also two insulated wires.  One will be the trigger wire and one will be the quench wire.

20091105-222150

You need to remove the cloth used to strengthen the cable because there won’t be room for it inside the 1/8 inch plug.

cut away the cloth
cut away the cloth

Next you’ll strip the insulated wires back about 1/4 of an inch (1cm) and then put a little solder on the wires to keep the them from coming un-braided.  This is a good time to slide the plug cover up on the wire before you solder the plug lines in place.

Solder the wires

Solder the wires

Now connect the 1/8 in plug. You can use a meter to figure out which is which but the ground (braid wire goes to the long center post on the 1/8 inch connector and the two others go either to the left or right small connectors.  You’ve got a 50-50 chance of guessing right so I just hooked the shoe to my flash which must be in TTL mode and stuck them in the holes and hit the trigger test button.  I got lucky and it work on the first try.  I also tried them the other way to see if they would work – they didn’t so I switch them back.


20091105-220516-Edit copy

The next step was to solder them in place and clip back the excess wire that sticks out.  I recommend that your run the wire from the inside to the outside so the excess is outside.  It will be much easier to cut off the extra wire that way.

Slide the wire back in place and you’ll be all done!

20091105-215431

The other end of the cable can be wired up the same way and used with an Nikon SB-800 by plugging it into the side 3 pin plug where it will work the same way as the shoe mount above and will look like this when it’s done.

Here it are shots of the shoe connected to a Nikon SB-600 and the 3 Pin connector to a SB-800.

20091106-200806
SB-600

SB800 and the 3 pin connector
SB800 and the 3 pin connector


The RP Cube lets me get an amazing range of power adjustment out of my Nikon TTL flashes and my Alien Bees and they can be mixed altogether in one shoot in three groups.

Using my meter, I test the range of the flash output between manual and RP Cube power adjustment and found that they match exactly but I think the knob allows for opportunities to adjust between the manual settings.



UPDATE: I’ve been contacted by several people saying the DIY didn’t work and each time it was because they hadn’t put the flash into TTL mode.  You have to be in TTL mode for the quench signal to work!  Don’t forget this simple but important step.

UPDATE: Here is a very cool DIY mod much like this setup that uses an internal 1/8 inch plug to eliminate the external cable being hardwired to the shoe.  You’ll need a cable to connect to the RadioPopper JrX but this should expand your options for cable length.  Nice work Aaron!






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Comments

  1. sCOTT says

    Great tutorial – I have confidence that I can actual do this.

    I have one question – I would just like to use my JrX basic to trigger my SB-800 – in manual mode. Do you know if the 3 pin – 1/8 stereo cord will accomplish that?

    Thanks!

    Scott

  2. says

    Scott,

    I only have the studios but I have used a “dumb” hotshoe without the TTL pins and it fires my SB800 without problem. It seems to me you only need the ground and fire wires to trigger the flash. The quench pin which is only programmed to work on Studio JrX wouldn’t be needed to make it work in the standard JrX. If you’re gonna wire up some of these hotshoes I’d plan for the future and wire them as if you had the Studio version because once you have one, you’ll never remember how you got along without it before. :)

    Let me know how your project goes.

    Tom

  3. says

    Thanks so much for the walk through. I followed your instructions and just completed (successfully) 6 RP cubes.

    I have a question regarding the 3 pin connector that got cut off. You put a 1/8″ stereo plug on the end and mention that “The other end of the cable can be wired up the same way and used with an Nikon SB-800 by plugging it into the side 3 pin plug where it will work the same way as the shoe mount above and will look like this when it’s done.” I’m not sure what you mean by this. Can I plug this converted cord directly into the JrX and be able to control the light output?

    Also, assuming that you can’t control the light output by the above, can you put another 3-pin connector on the end of one of the 3-pin connectors and run it from the RP cube to another Sb-800? Won’t that control the same light level to both strobes?

    Thank you so much,
    Bob Peak

  4. says

    Hi Bob, Sorry it took me so long to get back to you, I’ve been traveling.

    I’m glad the DIY was able to help you create your cubes. I’m loving them too.

    Regarding the “three pin plug” on the other end of the wire. The SB800 (and maybe others) has a port on the side that has the same three wires used in the shoe – The ground, fire, and quench. If you go through the same process of connecting the 1/8 inch stereo plug to the remaining piece of cable you’ll create a cable that functions exactly as the shoe and the JrX Studio combo. You will have the same control as with the shoe. I use one on a SB800 and it works great! This picture in the post shows the wire actually connected to the SB800 – just to the JrX via the 1/8 inch and you’re set!

  5. says

    I’m happy I could help, Carl. I hope you’ll show me some of the pics you make using them!

    Tom

  6. says

    I got my Radio Popper JrX studio kit and an extra receiver, and ordered two of the AS-E900 units from B&H. The units arrived quickly and work great. Missing from your tutorial is how to get everything working. The dials all seem backwards to me, so I thought that nothing worked at first because I was using the wrong dial, and had everything full strength when I thought it was off.

    Also as a note, I purchased the “Studio” version of the RadioPopper JrX units. The two receivers are labeled “Studio” but the Transmitter is NOT. I called them thinking they had sent me the wrong product, but they told me that only the receivers are Studio, not the transmitter. I was able to get everything working with the standard transmitter.

    Here’s what I did to get everything working, which you can use as a starting point to verify that your home-made RP Cubes are working:
    1. Transmitter on the camera, all pins “OFF”, except 5 is set to “ON” (which should disable the group if the dial is turned all the way down.
    2. Receiver at the flash has all pins “OFF”.
    3. Everything is powered off
    4. Slide the AS-E900 into the base of my SB-600
    5. Slide the 1/8 jack into the Radiopopper Receiver JrX Studio.
    6. Power on the SB-600. Set the unit to TTL mode. Back says “TTL” “M ZOOM” “NO AF-ILL”. Change the flash out of Manual mode and put it back to TTL mode for the RP Cube test.
    7. Power on the transmitter.
    8. Power on the receiver.

    At this point you can turn “down” the dial closest to the back of the camera and test fire. The strobe should not fire. Start to turn the dial towards the front of the camera and it will fire in varying strengths. If you can control the flash output, then everything is working properly.

    I now have two RP Cubes ready to be put to use and am super happy. Thank you SO much for this guide and the information. I contacted RadioPopper today and they said their RP Cube “is expected to be released before the end of the first quarter” of 2010. Even after the release I expect this solution will be much cheaper than the RP Cube product, and was simple to put together, making this a very viable alternative.

    Geoff Faulkner
    http://www.facebook.com/GeoffFaulknerPhotography

  7. Frank Blau says

    I have mine wired up, and it triggers the SB-800 in TTL mode, but the power is only at one setting, no matter how I adjust the JrX transmitter knob.

    Any ideas?

  8. says

    Hi Frank,

    I think there are few possible problems. The first is that you may have the wires switched or possible contacting each other inside the 1/8″ plug. The second and more likely problem is you established your flash/RP settings. Most important – be sure the flash is on TTL – not M.

    Below is a comment from Geoff and he goes into great detail about how to set everything on your flash and RadioPopper JrX transmitter and receivers.

    Here’s what I did to get everything working, which you can use as a starting point to verify that your home-made RP Cubes are working:
    1. Transmitter on the camera, all pins “OFF”, except 5 is set to “ON” (which should disable the group if the dial is turned all the way down.
    2. Receiver at the flash has all pins “OFF”.
    3. Everything is powered off
    4. Slide the AS-E900 into the base of my SB-600
    5. Slide the 1/8 jack into the Radiopopper Receiver JrX Studio.
    6. Power on the SB-600. Set the unit to TTL mode. Back says “TTL” “M ZOOM” “NO AF-ILL”. Change the flash out of Manual mode and put it back to TTL mode for the RP Cube test.
    7. Power on the transmitter.
    8. Power on the receiver.

    At this point you can turn “down” the dial closest to the back of the camera and test fire. The strobe should not fire. Start to turn the dial towards the front of the camera and it will fire in varying strengths. If you can control the flash output, then everything is working properly.

    -Tom

  9. says

    Just ordered 2 JRx transmitters, 3 “studio” receivers and 3 AS-E900 today because of this great tutorial/write-up. I can’t hardly wait to get them up and running instead of me running to my flashes for adjustments. It seems like this will be an awesome system. Thanks for figuring all this out and even more for sharing it.

    Clicks & flashes, Ben

  10. Mick says

    I just noticed that my JrX studio receiver came with a 35mm slave plug (http://i.imgur.com/3iRS0.jpg). I think it’s mono instead of stereo like the one from the Shack. Will it work or do I need a stereo plug. Thanks!

  11. says

    Hi Mick

    That plug won’t work with your JrX studios as the DIY mod plug. You will need a stereo plug to support the three signals: ground, trigger, and quench.

    Don’t throw away that mono plug though. It is used with Alien Bees to turn off the optical trigger when you connect the studios wit a phone cable.

    Cheers,

    Tom

  12. Mick says

    Thanks Tom. Got two done today finally. One question though – don’t know if you still use Nikon, but I notice that the pin at the bottom of my JrX transmitter is tad bit short. So when I put it on, I have to press it down a bit to ensure good contact with the shoe. If I don’t do that, my flash misfires a lot. I have a D300. Not sure if my unit is slightly defective or it is just the way it is. Thanks again for a great tutorial.

  13. says

    Congratulations, Mick! I am a Nikon and I use a D300. I think that you’re right about the short pins. Call the guys a RadioPopper. They have been very helpful when I called and offered advice and were willing to trade out a receiver if it had a problem – it didn’t (it was me) but would have traded it if it had.

    Enjoy your cubes and be sure to share your pics made with the DIY Cubes!

    Tom

  14. Scott says

    Maybe time to contact Mr King over @ RadioPoppers and ask for a job. Mr. Hobby mentioned RP may be looking to hire the Basic-to-Studio Hackers:
    http://strobist.blogspot.com/2009/08/radiopopper-jrx-will-make-you-fat-and.html

    One would hope they’d also be willing to hire someone to finally make a us a d#*! cube already, although Mr. Faulkner is prolly correct that those of us soldering-inclined will probably just make our own for the ~$15.

    Thanks for the great DIY!
    -Scott

  15. George G. says

    Just got done manufacturing several as per the great write up. They not only work perfectly with my SB-800, but with SB-26′s and SB-28′s as well. Woo-hoo!

    A couple of items that others might find useful:
    1) When wiring things up, the white wire goes to the center of the plug.

    2) Out of the 12 Radio Shack plugs I bought, two were defective internally (as determined with a multimerer). Radio Shack carries more expensive plugs too; next time I’ll pay a couple of dollars more.

    3) You can “daisy chain” cubes with the cables or with unadulterated AS-E900′s to use one popper to control several flashes. Having two mounted together to double the light will be useful.

    Thanks for the detailed instructions.

  16. says

    Thanks for the input George! From what I’ve gathered from folks, the only Nikon TTL flash that won’t work with this setup is the SB900. It apparently uses a different method of firing than the trigger/quench method.

    Tom

  17. says

    Hi,

    This is a great article, but I am still a little confused. I have 2 sb-800 and the JRX studio. Does that mean the diy cube will not work with power levels and I have to make the 3 pin connector? Or does both (cube and 3 pin) of them do the same thing?

  18. says

    Hi Mike,

    The cube and the three pin cable both do the same thing – adjust the flash power!.

    Tom

  19. says

    Cost. You can have the ability to adjust both of your SB800s for the price of just one AS-E900 hotshoe and 2 1/8 stereo plugs.

    Tom

  20. says

    ok….I am dumb!!! ahhhh!! I ended up ordering 2 as E900…..stupid….hopefully I can still cancel one of the orders….

    thanks for the replies.

  21. says

    No worries. I’d keep the order as is. I like the hot shoe mount better than the wire but it does the job.

  22. Sandro says

    Here it is what I did. Radiopopper Jr Studio with 3 flashes SB-24/25. Today i have 4 flashes and can control the power output of all from my camera.
    [img]http://www.entre-vista.com/images/rpjrstudio-sb1br.jpg[*img]

  23. says

    Hey Tom,

    Thank you for the fantastic write up. I followed your post and really brought down the $$$ of remote triggering by making my own RP cubes.

    I often shoot with speedlights grouped in pairs or triples, and have found that the JrX studio system allows for multiple speedlights to be tethered together tethered via AS-E900 and the DIY RPcube!

    I made a post of it on my blog here and have referenced/linked back to your site for the terrific write-up (hope you don’t mind).

    http://pixeldustphoto.blogspot.com/

    Cheers,
    -Hien

  24. photomy says

    I believe the SB900 ONLY fires with specific digital code signals. Either through the foot when in the flash shoe or cabel, or via IR code pulses.

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