czwartek, 17 lipca 2008

New PT-04 antenna mod

click to see the notesRecently, blog grow in popularity, people liked the idea of using small off-shoe strobes to raise the quality of light in their pictures. They can trigger those strobes by cable, optic, or radio transmitters. The last option is the most comfortable, but a good set of quality radio triggers costs a lot - You pay more for reliability and range.

What is the biggest confusing thing about cheap radio remotes from ebay ('cactus', 'pt-04' and other similar ones)? I've heard that after some time they just stop working even if batteries are replaced for new ones... my cheap radio triggers are still working fine (got them for about 6 months) and the only feature which made me confused was low range. After googling the topic I've found a lot of information about increasing its range with external antennas on transmitters. It worked for some people, and others were complaining that the antena shortens its radio range, at the end there were some complaints about increased noise after installing the antenna. I've changed the direction of thinking. If You believe that new transmitter antena increases noise just leave it... and still get better range with Your remotes. How?

I've decided to create external antena for receiver , other than transmitter - if the antena will be far away from my dSLR's body, it will not bring any extra noise to my pictures. The length of radio wave which is emmited by remotes is 0.69m, I used wire 1/4th of that wavelenght (about 17cm) to create my experimental antennas (You can use the whole length or 1/2, haven't tried it yet - maybe the range will be even better when longer antenna is used).

Where to solder antenna? Well I've located built in antenna in my remote receiver - a short piece of wire above board and decided to connect my antenna to the existing one. But where? I tried on both sides of existing antenna and believe me - it really matters where You solder it. Fristly, when I tried to solder my antenna (click on the image to see larger one, then move Your mouse to see the notes) I was disappointed with the results - the range decreased to about 0.2m. Then, I soldered it to the second end of existing antenna (click on the image to see larger one, then move Your mouse to see the notes) - and it was it. The range increased a lot, and that was all I need - 17cm of wire, and total 30 minutes of my precious time :)

Field test results (I think that it may vary on the power of batteries & antenna length accuracy):
- normal (without antenna) PT-04 about 5m with no misfired shots,
- my mod'ed PT-04 almost 35m with no misfired shots,

After some time, accidentally I've found another cool way to increase even more range of my remotes. In the transmitter You can find socket for the jack cable (and there was short extra cable to connect the reviever to flash [other than hot-shoe flash]), if You will put the PC cord into the jack of transmitter, You will make the simpliest external antenna. I didn't found any extra noise on my pictures, so the theory of extra noise from transmitter antenna seems ridiculus to me - it may be promoted by people who are selling the more expensive radio remote systems. Connecting this cable should give You about 7m of extra range.

If You have any questions - ask in comments, I will try to answer as soon as possible. If You will make that mod, feel free to post the range You got without misfired shots.

4 komentarze:

  1. Hey man! Excellent work! I've always wondered is there a way to extend the range of the receiver itself, other than just the transmitter.

    And just let me correct you. Noise from transmitter antenna is not promoted by people who are selling the more expensive radio remote systems. It happens with Cactus triggers, but not with all cameras.
    Just for instance, I've been using Olympus E-330, and i had very bad noise in the upper frame of the photo in every photo above ISO 200. After that I've been using several other cameras (Olympus E-1, E-510 and recently E-3) and none of them showed any trigger-induced noise like the E-330 did. I have read that it was due to the location of the A/D converter on the CMOS sensor (if it's located n the upper side of the camera, it interferes with the trigger, but cameras with CCD sensor doesn't affect that)

    So, let's get back to your mod. I think it's excellent, and I'd like to try it on my own Cactus trigger. Not just to extend the range (which is over 70m due to the transmitter mod I've done), but to ensure the good signal to the receiver itself.

    Can you please post a larger photo of the place where you have soldered the antenna?

  2. here it is:

  3. Hello Robert,
    I just ordered the Cactus set and your solution for increasing the working range seems a very simple one. I still have a few questions. You wrote that bij accident you discoverd the use of the PC cord. Is that the same cord that comes with the Cactus set and what length do you use? Did you try the PC cord without the wire-antenne on the receivers, or is it just the combination?
    Kind regards Roelof

  4. @familieheidahavinga:

    I've used the cord that came in package with my wireless triggers, and tested it with my antenna mod (all of my recievers are moded in that way, so it is hard to say if it would work that good without my mod).