Cactus Mod - Antenna Extension?

Discussion in 'Photography Beginners' Forum' started by danman281, Nov 28, 2008.

  1. danman281

    danman281 TPF Noob!

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    So far I have found two websites concerning this mod:

    1. http://jerryphpics.blogspot.com/2008/07/004-cactus-v2s-modifications.html
    2. http://jeremykuster.blogspot.com/2007/10/gi-cactus-v2s-modification-tutorial.html
    Both of them have good write ups, however something doesn't make sense. In the first website, they said to solder on the "antanna" onto the bottom left corner. On the second website, they soldered it onto the bottom right(next to the battery). When I soldered it on the bottom left with a simple coiled wire, it didn't work (lost distance actually). See figure a1 below.

    [​IMG]
    figure 1a - my attempt

    I decided to take it off since it didn't do anything. Btw... was that circuit important? Did I damage it by any chance? It still works...

    Normally, the cactus is really inconsistent after a few feet away. Even from ten feet it may miss 1/10 tries or more. With the DIY (from the first link) loop wire antenna, I lost range. This may be because thats not how antennas work (at least from how I learned) OR it's not the correct antenna circuit. I then held the same wire on the other circuit and tested roughly 100 feet away and it worked (somewhat). When I took it off, it no longer worked. This must mean that the bottom right circuit is for the antenna. Can someone still confirm this please?
     
  2. Dweller

    Dweller Inconspicuous Supporter

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    From what I have read, either spot should work, but some people seem to have better luck with the hole next to C3.

    How long of a wire are you using?
     
  3. dEARlEADER

    dEARlEADER TPF Noob!

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    (watching thread)

    I have yet to mod my triggers. Why doesn't gadget infinity just add a small antenna to their triggers? The small increase in cost would allow them some pretty impressive range bragging.
     
  4. Big Mike

    Big Mike I am Big, I am Mike Staff Member Supporting Member

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    They don't make them, they just sell them. It would be cost prohibitive to do the mod themselves.
     
  5. danman281

    danman281 TPF Noob!

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    Guys, I'm having trouble with the consistency. Most of them time, even ten feet away I don't get anything. It will work 99 percent of the time if I have it within 1.3 feet. After that it drops exponentially. It barely works at 7 feet. I read someone else's post that their cactus trigger goes beyond 100 feet with no mod.

    I ran another quick test. I walked aprox 10-15 feet where it normally wouldn't work. I then used the makeshift wired antenna towards the circuit and it worked but inconsistently. This means that the antenna circuit must be helping a little...

    How well does everyone else's cactus work without the mod? I doubt these things come out of the box this crappy
     
  6. Big Mike

    Big Mike I am Big, I am Mike Staff Member Supporting Member

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    Have you tried putting in a fresh battery?
     
  7. dEARlEADER

    dEARlEADER TPF Noob!

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    Have you replaced the batteries as suggested by many?
     
  8. danman281

    danman281 TPF Noob!

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    I got this in the mail today and the batteries were brand new. Should I buy new batteries anyways?


    To answer Dweller's question: The length of the wire I used was roughly 12'' coiled up
     
  9. Big Mike

    Big Mike I am Big, I am Mike Staff Member Supporting Member

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    Those batteries might have been sitting there for a long, long time. This is a budget product, it wouldn't be uncommon to get old 'nearly dead' batteries.
     
  10. danman281

    danman281 TPF Noob!

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    I checked both batteries using a multimeter.

    The Receiver uses: CR2 3V Alkaline Battery
    The multimeter read: 3.2 V (good)

    The Transmitter uses: L1028 12V 23A Battery
    The multimeter read: 12.2 V (good)

    The batteries seems to still be in working order.

    Was it possible that the first soldering job damaged the circuit board? I don't see how thats possible though. Even if I did, the other antenna circuit is still there. Any electrical engineers in this forum? lol
     
  11. tirediron

    tirediron Watch the Birdy! Staff Member Supporting Member

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    I don't know what frequency the cacti operate on; the link refers to an AE 12.39 inches long. Has anyone double-checked the math to ensure that that's a full fraction of the wavelength?
     
  12. Dweller

    Dweller Inconspicuous Supporter

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    I can not vouch for the accuracy of this comment, but here a user comment states:

    edited to add:

    According to this site the proper length for 433Mhz should be 12.97 inches for 1/2 wave and 6.48 inches for quarter, so it sounds like the antenna may be a bit short. I do not know if its enough to cause a problem but its something to consider.
     
    Last edited: Nov 28, 2008

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