Re: CCTV Video issues

["Roland Moore" <roland@xxxxxxxxxxxx>]

>But the domes inside suffer from all kinds of distortion.
I have seen things powered from 12VDC not work when the fine print said
24VAC on the cameras. Another sad problem may be that the power supply you
are using has self restoring circuit breakers. A good idea in some
applications, but not on cameras. The circuit breakers trip too slowly and a
camera can be damaged before the circuit blows. Only use fused outputs on
camera jobs, unless you don't mind replacing damaged cameras. They are more
expensive than fuses however.
Another problem might be a grounded wire. It can pick up some building A/C
and give the uglies to the video. There are several ways to check it, even
if you don't know how to check for grounds and inductances. Try viewing a
single camera via a monitor that is not connected to the DVR. Get a good
picture established leg by leg until you find the guilty dog.

> Lastly, I'm looking for a portable meter to measure video strength but
> I don't know what it's called to even begin searching.  Help?!
We have such a device. It is expensive. I think in the $700 to $1000 range
if I remember right.  We keep it in its own briefcase sized case for
protection.  I only use it when factory tech support needs to be convinced
they have a problem and not me. It measures very specific items from the
camera. You could even focus a camera with it without even seeing the actual
video image once you get used to using it. If you're using 12VDC cameras it
sounds like you're fishing in the low end of the price market. It is hard to
justify that kind of expense in that market segment. I would call around to
a few pawn shops or try eBay and see if you get lucky.
What you are looking for is something like this:
A Camera Master I or Camera Master II
http://www.fmsystems-inc.com/prod_list.cfm?cat=test&industry=none
WHAT ARE IRE UNITS ?IRE Units are used worldwide to measure video signal
amplitude instead of Volts Peak-to-Peak. This system of measurement is much
easier to use than Volts Peak to Peak and can be directly measured on the
CM-1 hand-held, battery-operated Camera Master instead of a bulky Wave Form
Monitor that requires 120 VAC power. The following table defines the
amplitude of various parts of a video signal. In terms of IRE Units and
Volts.

      MEASUREMENT I.R.E. UNITS VOLTS
      Sync Pulse 40 0.285714----
      Color Burst (p-p) 40 0.285714----
      B/W Picture 100 0.714285----
      Color Picture 120 0.857142----
      B/W Composite (p-p) 140 1.000000----
      Color Composite (p-p)  160 1.142857----



I hope this helps.


"S. Smith" <ChaosLogicXIII@xxxxxxxxx> wrote in message
news:1168659847.562911.156810@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
> It's a big job... so we figured we'd do it right, but when everything
> was plugged in, it was so wrong.
>
> We ran everything in CAT5E and used passive baluns to make the
> connections.  Funny thing, the longest runs went outside of the
> building to "box cameras". They look great!  But the domes inside
> suffer from all kinds of distortion.  Even the closest camera at a mere
> 30ft!  We're powering them all from a 12VDC Altronix power supply.
>
> My first thought was interference caused by electrical cables or
> flourecent lighting.  But the outside cams take the same path as the
> domes without side effects.  This leads me to believe that there may be
> a power issue.  I'm wondering if the dome cameras don't have the "umph"
> to push the signal back to the DVR cleanly.  Suggestions?
>
> Lastly, I'm looking for a portable meter to measure video strength but
> I don't know what it's called to even begin searching.  Help?!
>
> Thanks!
>