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johnnyjb

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Everything posted by johnnyjb

  1. Could anyone give me info or a link that ll explain the ins and outs pros cons of access control This might be askin too much but im eager to learn more about it as im applyin for a job in cctv again and want to get a grip on this line of work Thanks Johnnyjb
  2. johnnyjb

    Infared

    How come you can see the red glow from a camera with infared diodes around it. i didnt think we could pick up infard light
  3. How would a ground loop occur with a camera.I just couldnt bother racking my brains trying to figure out how it happens
  4. johnnyjb

    Ground loop

    How would you wire a ptz mounted on a pole outside would you use ground or earth on power supply transformer and do same back at supply for transformer coming out.If you isolate the camera so that it is 'floating, a loop should not happen is that what your sayin?
  5. johnnyjb

    Ground loop

    So what your sayin is if you had a charge at the matrix,dvr or whatever the coax is connected to internally coax could act as a conductor or loop and current could flow down coax reachin the Camera.Would this only apply to external cameras or are internal subjected to the same conditions
  6. I used install cctv but left before i got the whole trade learned but am confident all the same My question is we always used 2 cores(i think) to Ptz for telemetry but once we used a 4 core system.What are the four cores for I hope im making sense here
  7. johnnyjb

    4 core data

    Is two core used for just basic moving of camera and 4 core is for more advanced information i.esending lacation of camera as stated above 4 core would only be used in big jobs i assume
  8. johnnyjb

    4 core data

    Thanks alot for your answers
  9. Could any body give me a list (or link)of the main coaxial video cables and their good bad qualities and preferred uses I hope this is not to much hassle
  10. johnnyjb

    Hi im john

    Hi i just registered and will use this forum for info as i used to install cctv and am interested in getting involved again soon Thanks
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