Anyone know what this is?

Discussion in 'General Electronics Chat' started by Romes, Oct 12, 2014.

  1. Romes

    Thread Starter Member

    Sep 30, 2014
    53
    0
    Like the title asks, anyone know what this is? Looks like something that may be useful....
    The interwebs comes up with nothing in relation to the markings....
     
  2. nerdegutta

    Moderator

    Dec 15, 2009
    2,519
    786
    Could it be a fuse of some sort?

    Where does it come from?
     
  3. MrChips

    Moderator

    Oct 2, 2009
    12,452
    3,371
    It is an analog delay line. It delays a signal by nano-seconds.
     
  4. Romes

    Thread Starter Member

    Sep 30, 2014
    53
    0
    Thanks for the quick responses!

    It comes from output of a old video doo-hikey. Had something like six stages, each on its own removable board. Must have been expensive in it's day. Bought it for parts for $20.

    So why would one want to delay a signal by nano-seconds?
     
  5. Lestraveled

    Well-Known Member

    May 19, 2014
    1,957
    1,215
    On old video displays, time was equal to position on the screen. Also, a delay line of that size could delay in the microsecond range. The numbers next to the terminals probably indicate delay time. Don't throw all of them away. It's a cool part.
     
  6. MrChips

    Moderator

    Oct 2, 2009
    12,452
    3,371
    Because the signal was appearing too early for that part of the circuit in the video doo-hickey.
     
    Prince_nqobani and BMorse like this.
  7. MrChips

    Moderator

    Oct 2, 2009
    12,452
    3,371
    I assume 590 printed on the delay line is 590ns.
     
  8. Lestraveled

    Well-Known Member

    May 19, 2014
    1,957
    1,215
    It could be 590us.
     
  9. MrChips

    Moderator

    Oct 2, 2009
    12,452
    3,371
    If the old video doo-hickey is an analog oscilloscope with a CRT, the input signal goes to a comparator circuit in order to trigger the horizontal sweep circuit. The input signal is simultaneously routed to the vertical amplifier to be displayed on the CRT.

    By the time the comparator detects the pulse or edge on the input signal it is gone and cannot be viewed on the CRT.
    Hence they delay the input signal before sending it to the CRT. Now you can see the leading edge that caused the scope to trigger.

    It is exactly like viewing an event before it happens. Like seeing a what led up to a crash.
     
    Gdrumm likes this.
  10. MrChips

    Moderator

    Oct 2, 2009
    12,452
    3,371
    No way. 590us is a looong time.

    I have a number of these delay lines and the longest I have seen is about 1-2us.

    Propagation delay is about 5ns/m.
    For 500us you would need about 100km of wiring in the delay line.
     
    Last edited: Oct 12, 2014
  11. Lestraveled

    Well-Known Member

    May 19, 2014
    1,957
    1,215
    Yea, you are right. 590ns. These are probably RGB color correction delay lines.
     
  12. Romes

    Thread Starter Member

    Sep 30, 2014
    53
    0
    Fair enough, that makes sense. Would I be able to make an analog sound delay with one (or two of 5) of these, I suppose not since the time increments are probably not long enough to be of any use..... although I have never timed a delay FX pedal.
     
  13. MrChips

    Moderator

    Oct 2, 2009
    12,452
    3,371
    No. The delay in an FX pedal are of the order of tens and hundreds of milli-seconds.
     
  14. Romes

    Thread Starter Member

    Sep 30, 2014
    53
    0
    Shucks, thanks.
     
  15. KL7AJ

    AAC Fanatic!

    Nov 4, 2008
    2,040
    287
    Could be from an oscilloscope...but I don't recognize it specifically
     
  16. Romes

    Thread Starter Member

    Sep 30, 2014
    53
    0
    The stages were: Power,Gate,Horz (horizontal) , Clamp, and Video. In that order.
     
  17. ian field

    Distinguished Member

    Oct 27, 2012
    4,415
    784
    As an example; in the PAL CTV system, the luma and chroma signals encounter different amounts of delay as they pass through their respective processing circuitry - if the luma wasn't passed through a delay, the colour and brightness wouldn't line up together on the CRT face.
     
  18. AnalogKid

    Distinguished Member

    Aug 1, 2013
    4,546
    1,252
    What kind of video doo-hikey? If it's a camera or camera controller, this probably is part of the image enhancer. If its a video recorder, this probably is part of the timebase corrector. The problem is that 590 us or ns doesn't work for either NTSC or PAL.

    ak
     
Loading...