Page 1 of 2 12 LastLast
Results 1 to 10 of 11

Thread: generic DB25 cables

  1. #1
    Join Date
    Sep 2015
    Posts
    98

    Default generic DB25 cables

    i'm in a jam, have a show today and need longer cable. have only purchased online via "ILDA cable sellers." would getting a DB25 cable locally from MicroCenter work? and is there any possible harm in trying? I need to put my laser farther away than i thought and dont have long enough cable and show is later this evening, any tips?

  2. #2
    Join Date
    Apr 2016
    Posts
    162

    Default

    Maybe those Db25 to RJ45 (LAN) adapters on both ends and a ethernet cable will work?

    PS. I have used a 3 meter long printer DB25 cable for my lasesr for years and didn't experience any issue.

  3. #3
    Join Date
    Oct 2012
    Location
    Germany
    Posts
    1,478

    Default

    ... to get longer high-speed data transmission without active amplifying over longer distances (some ten to hundred meters) I've soldered small resistors of some ten Ohms in the data wires.

    This mostly reduces spikes and crossover and seems to give better filtering than ferrite rings ...

    Viktor

  4. #4
    Join Date
    Sep 2015
    Posts
    98

    Default

    i ended up just putting projector next to my dac since all radioshacks and microcenters in my area dont carry db25 stuff anymore! surprise!

  5. #5
    Join Date
    Sep 2015
    Posts
    98

    Default

    if i wanted to ditch the large plastic connector with the big screws for a low profile flat ribbon style db25 connector for my laser system, would something like this work:

    http://www.jameco.com/webapp/wcs/sto...10001_12408_-1

    if anyone has recommendations as to where to purchase something like this let me know..!

  6. #6
    Join Date
    Apr 2016
    Posts
    162

    Default

    Quote Originally Posted by maxcady View Post
    if i wanted to ditch the large plastic connector with the big screws for a low profile flat ribbon style db25 connector for my laser system, would something like this work:

    http://www.jameco.com/webapp/wcs/sto...10001_12408_-1

    if anyone has recommendations as to where to purchase something like this let me know..!
    Don't. Its too fragile and I don't think you'll find long ones. Ribbon cables are good inside your projector.

    I tried using a pair of cheap ethernet cables. Length for each was 30 meters. It was not the cheapest kind as it had foil shielding but not expensive either as didn't have braided aluminum shielding and thicker signal cables. Was rated for up to 100 meters. Worked perfectly fine for laser projection at 30. Maybe would work as well at 100 meters, I simply had no reason to make such a long one.

    One question though, I soldered the pins in order, matching the next ilda pin in line to the next rj45 pin. Is this okay or should I have soldered the braided couples for the positive and negative signals respectively. I don't know much about signal transfering to know if this matters or not for getting stronger signal at the same distance.

  7. #7
    Join Date
    Jun 2010
    Location
    Blacksburg VA
    Posts
    137

    Default

    Using the twisted pairs as positive and negative rejects noise better than random assignment (and ribbon cable). That used to be a huge problem when there were illegally powerful CB and taxi radios everywhere. If you are in a quiet electrical environment it may not matter.

  8. #8
    Join Date
    Jan 2006
    Location
    Charleston, SC
    Posts
    2,147,489,446

    Default

    Quote Originally Posted by DanBarlow View Post
    Using the twisted pairs as positive and negative rejects noise better than random assignment (and ribbon cable).
    One caveat if you're going to use cat-5 (or cat-6) and wish to use the twisted pairs for X+/X- and Y+/Y- to help with noise reduction: Remember that the pin order on the RJ45 does not put all twisted pairs together on adjacent pins. There are two standards (T-568A and T-568B) for wiring an RJ-45, and they each have only three of the four pair rung out on adjacent pins. I've always used T-568B, which is White-orange, Orange, White-green, Blue, White-blue, Green, White-brown, Brown.

    But no matter which standard you encounter, the first two pins on the left and the last two pins on the right will each be a twisted pair, and then the middle two pins will be the third one. To use the last pair together, you'll want to use pins 3 and 6.

    Also, some controllers only use single-ended signalling for color, which means the negative color signal lines are all tied to ground at the controller. If that is the case with the controller you use, then there's no point in using up extra conductors (and pins) for the negative color signal for each color channel. Just link them all to ground at the projector (pin 25 on ILDA). The same thing goes for the shutter signal, if you use it.

    Adam
    Last edited by buffo; 07-24-2016 at 06:02. Reason: removed extra quoted material...

  9. #9
    Join Date
    Sep 2015
    Posts
    98

    Default

    Quote Originally Posted by Nii View Post
    Don't. Its too fragile and I don't think you'll find long ones. Ribbon cables are good inside your projector.

    What's the worst that could happen if i tried using the one from the link i posted above? I really need a low profile ribbon coming out of my modular synthesizer. Using a generic DB25 with the big plastic connector and thick cable gets in the way alot during patching, and also gets caught on other patch cables and im always worried i'm going to tug too hard on the actual ILDA connection on my module. If the worst thing that could happen is the ribbon cable stops working properly, thats fine by me. I was thinking of using a low profile right angle ribbon to just get the cable out of the vicinity of the rest of my modular patching, and then plug it into a proper ILDA cable with plastic connector and thick heavy shielding etc. If i had a few of these low profile ribbon cables on hand in case one breaks, and all i'm doing is recording and "jamming" with my system to come up with new material, then what could be so bad?

    I'm also intrigued by this idea of using an adapter that changes db25 to ethernet if thats a more proper way to do low profile long cable runs. any recommendations for that stuff? low profile adapters maybe?

  10. #10
    Join Date
    Aug 2016
    Posts
    17

    Default

    The picture on the site is not great but if I'm right its a simple grey ribbon cable people put inside electronics that is sensitive to bending and the individual lanes can easily get stripped so they are not usually used outside.

    If the lanes responsible for the scanner's X and Y signal get damaged you may end up with a static beam shooting somewhere you didn't want, potentially at someone. Not worth the risk.

    Stanwax sells db25 to 2x ethernet adapter. It's just a passive adapter. You can also directly solder two ethernet cables to a db25 connector plug. Those connectors have large holes that can fit more than two ethernet cables.
    I'd get an aluminum shell DB-25 connector plug as the plastic ones from china are fragile.
    Last edited by Yol8r; 08-21-2016 at 22:18.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •