Splitting a CCTV signal to two monitors

[Henry Hallam]

Hi,
Is it possible to use an ordinary BNC T-splitter (one female, two male)
to split the signal from a camera so that I can watch the video from a
CCTV camera on a monitor while also capturing it on a computer with a
capture card? Or would I need more sophisticated electronics?

Thanks very much

Henry Hallam

[junk01@intactivist.org]

Henry Hallam wrote:
> Hi,
> Is it possible to use an ordinary BNC T-splitter (one female, two
male)
> to split the signal from a camera so that I can watch the video from
a
> CCTV camera on a monitor while also capturing it on a computer with a
> capture card? Or would I need more sophisticated electronics?

Yes, it's possible to split it that way although you will lose some of
the strength of the video signal because both devices are terminated
with a 75 ohm resistor. If one of the devices allows you to disable the
75 ohm load then that would be best, but I find the drop of splitting a
signal once, to be tolerable. Another option is to buy an actual video
splitter, or you could always remove the 75 ohm resistor from one of
your devices :)

[Robert L. Bass]

> Yes, it's possible to split it that way although you will lose some of
> the strength of the video signal because both devices are terminated
> with a 75 ohm resistor.

Most professional video monitors have selectable termination to switch the
75-Ohm in or out as needed. Most pro grade units have a feed through
connection to allow viewing while passing the signal on to either another
monitor or a recording device.

> ... I find the drop of splitting a signal once,
> to be tolerable. Another option is to buy an
> actual video splitter...

If the camera isn't junk (eg, X10) you can split the signal two ways without
discernable loss. Ordinary video splitters don't amplify the signal so they
won't be any better and some can even make things a little worse.

--

Regards,
Robert L Bass

=============================>
Bass Home Electronics
2291 Pine View Circle
Sarasota · Florida · 34231
877-722-8900 Sales & Tech Support
http://www.bassburglaralarms.com
=============================>

[Frank Olson]

"Robert L. Bass" <robertlbass@comcast.net> wrote in message
news:neudnUVN4YKj9OTfRVn-gQ@comcast.com...
>> Yes, it's possible to split it that way although you will lose some of
>> the strength of the video signal because both devices are terminated
>> with a 75 ohm resistor.
>
> Most professional video monitors have selectable termination to switch the
> 75-Ohm in or out as needed. Most pro grade units have a feed through
> connection to allow viewing while passing the signal on to either another
> monitor or a recording device.

It's called a "looping output". On most DVR's or multiplexers the "looping
output" is used to go to another device such as a monitor which remains
*fixed* on the one camera. You could loop all the inputs on some
multiplexers to go to a second remote multiplexer at a guard shack for
instance. The looping output on a monitor will only allow you to "see" what
the first monitor does without any control over the camera input (if the
second monitor's remote from the multiplexer). On a single camera system
that wouldn't be a problem, but when you have more than two cameras you may
want to exercise more "control" over what you see on the second monitor.

[Robert L. Bass]

"Frank Olson" <feolson@shawcdn.ca> wrote in message
news:72xfe.1283917$Xk.712824@pd7tw3no...
>
> "Robert L. Bass" <robertlbass@comcast.net> wrote in message
> news:neudnUVN4YKj9OTfRVn-gQ@comcast.com...
>>> Yes, it's possible to split it that way although you will lose some of
>>> the strength of the video signal because both devices are terminated
>>> with a 75 ohm resistor.
>>
>> Most professional video monitors have selectable termination to switch
>> the 75-Ohm in or out as needed. Most pro grade units have a feed through
>> connection to allow viewing while passing the signal on to either another
>> monitor or a recording device.
>
> It's called a "looping output". On most
> DVR's or multiplexers the "looping output" is used to go to another device
> such as a monitor which remains *fixed*
> on the one camera.

He only has one camera. The looping feed through (looping) output of the
monitor will work fine for his needs.

> The looping output on a monitor will only
> allow you to "see" what the first monitor
> does...

That is precisely what the gentleman asked for.

--

Regards,
Robert L Bass

=============================>
Bass Home Electronics
2291 Pine View Circle
Sarasota · Florida · 34231
877-722-8900 Sales & Tech Support
http://www.bassburglaralarms.com
=============================>

[Frank Olson]

"Robert L. Bass" <robertlbass@comcast.net> wrote in message
news:5fqdnQXVio_IWePfRVn-pQ@comcast.com...

>
> That is precisely what the gentleman asked for.


I wasn't criticizing your response. I was expanding on it to include the
proper terminology. If you feel my response was inappropriate (in light of
the discussion we were having in another thread) then that's an issue you're
going to have to deal with. I do try to ensure my explanations are as
detailed as possible. For instance, when I instruct someone to "turn off"
or remove the power from a panel, I usually include the correct sequence for
disconnecting AC and battery in accordance with the manufacturer's
recommendations.