Extending CAT5 cable

[klem kedidelhopper]

We need to run video over some existing CAT5 cables using baluns on
either end. The existing cables are all terminated with jacks on both
ends. One end is a patch panel and on the other end they are connected
to jacks which are mounted on the baseboards. We plan to make 8 foot
cables with an RJ 45 on one end, plug it into the baseboard jack, run
the cable up the wall and then connect the other end to the balun and
then to the camera. Would it matter if this short piece of cable were
CAT3? Thanks, Lenny

[William Sommerwerck]

Given that CAT3 is spec'd only to 16MHz, * and CAT5 is spec'd to 100Mhz, you
might run into problems with wideband signals.

As this cabling isn't horribly expensive, why not use CAT5?

* I'm obliged to anticipate the obvious objection -- "But that doesn't mean it
won't work at 100MHz." True. But it isn't spec'd at that frequency, so you
have no guarantee how it will perform.

[gregz]

I see it working best if your only using one pair.

Greg

[Cydrome Leader]

why would you use cat3? Also where do you even get cat3 unless you're a
copper thief these days?

I'd use silver satin, or some 1980s 50 foot coiled kitche telephone cords,
with a handset swivel thingy on it, with nothing but the finest and most
reasonably priced rj11 to rj45 adapters from Black Box.

[klem kedidelhopper]

On Jan 8, 1:40 pm, Cydrome Leader <prese...@MUNGEpanix.com> wrote:

Well the obvious reason to use CAT 3 is because as a former telephone
systems contractor I happen to have a shit load of it and I didn't
want to have to buy any additional CAT 5 at this time. Was that so
difficult to figure out? Most people that visit this group are not
thieves, nor are they idiots. So don't act like one. You have no
audience. We ask questions because we're looking for some advice from
someone more knowledgeable than ourselves. And personally I really
appreciate it when I get assistance with a problem. So if you really
need to be a smart ass, please don't bother responding to my posts.
Lenny

[klem kedidelhopper]

On Jan 8, 10:49 pm, klem kedidelhopper <captainvideo462...@gmail.com>
wrote:

I just thought of something else. If CAT3 is spec'd out to 16MHZ and a
typical NTSC TV channel was 6MHZ wide with 250KHZ guard bands on
either end why would CAT3 cause any problems in a video application?
It seems to exceed the requirements for TV video. Lenny

[gregz]

Regardless of the cable, it will have high frequency loss. It should work
fine, unless you start to see two of everything. Shadows ?

Greg

[stra...@yahoo.com]

On Jan 7, 4:13 pm, klem kedidelhopper <captainvideo462...@gmail.com>
wrote:

The main problem is driving and terminating the CAT cable at the
correct impedance. Improperly terminated cable for video make for some
poor video but it depends on your needs/demands. What I think is bad
may be more than sufficient for you - or not.

G²

[Michael A. Terrell]

klem kedidelhopper wrote:
>
> I just thought of something else. If CAT3 is spec'd out to 16MHZ and a
> typical NTSC TV channel was 6MHZ wide with 250KHZ guard bands on
> either end why would CAT3 cause any problems in a video application?
> It seems to exceed the requirements for TV video. Lenny

It's not flat to 16 MHz. NTSC channels start at 54 MHz so the video
has to be baseband. Even with BalUns the response isn't flat for
baseband video. Switching to a different cable with different twist
rates can cause problems, as well. This is from a retired TV broadcast
engineer. :)

[klem kedidelhopper]

On Jan 10, 9:09 am, "Michael A. Terrell" <mike.terr...@earthlink.net>
wrote:

I do understand what you're saying about impedance mismatches and I
can also see where marrying this cable with some (probably) Chinese
baluns which are "supposed" to be constructed correctly could upset
impedances, but Base band video was what I was referring to. So in
that sense the response demands of the cable and the baluns would be
limited to 4 or at best 5MHZ right, and then in theory wouldn't even
CAT 3 be overkill?
Lenny

[William Sommerwerck]

I do understand what you're saying about impedance mismatches and I
can also see where marrying this cable with some (probably) Chinese
baluns which are "supposed" to be constructed correctly could upset

impedances, but baseband video was what I was referring to. So in

that sense the response demands of the cable and the baluns would be

limited to 4 or at best 5MHz (right?), and then in theory wouldn't even
CAT3 be overkill?

Probably. But CAT5 or CAT5e aren't horribly expensive, nor do you need a lot.
I understand you don't want to waste materials you already have, but why not
just buy the matching type, and that will be one less thing to worry about?

[Michael A. Terrell]

klem kedidelhopper wrote:
>
> On Jan 10, 9:09 am, "Michael A. Terrell" ?mike.terr...@earthlink.net?
> wrote:
> ? klem kedidelhopper wrote:
> ?
> ? ? I just thought of something else. If CAT3 is spec'd out to 16MHZ and a
> ? ? typical NTSC TV channel was 6MHZ wide with 250KHZ guard bands on
> ? ? either end why would CAT3 cause any problems in a video application?
> ? ? It seems to exceed the requirements for TV video. Lenny
> ?
> ? It's not flat to 16 MHz. NTSC channels start at 54 MHz so the video
> ? has to be baseband. Even with BalUns the response isn't flat for
> ? baseband video. Switching to a different cable with different twist
> ? rates can cause problems, as well. This is from a retired TV broadcast
> ? engineer. :)

> I do understand what you're saying about impedance mismatches and I
> can also see where marrying this cable with some (probably) Chinese
> baluns which are "supposed" to be constructed correctly could upset
> impedances, but Base band video was what I was referring to. So in
> that sense the response demands of the cable and the baluns would be
> limited to 4 or at best 5MHZ right, and then in theory wouldn't even
> CAT 3 be overkill?

It has a lot more tilt than you think. What brand & type number is
the CAT3 you have on hand?

-----------------------------------------

This Belden CAT3 has:
MHz Loss @ 100 meters
0.772 2.2
1.000 2.6
4.000 5.6
8.000 8.5
10.000 9.7
16.000 13.1

Which is a 3.4 dB rolloff between .772 MHz and 4 MHz at 328.08 feet.
http://www.belden.com/pdfs/techinfo/DS_D_Inside_Horizontal_Cable.pdf

-----------------------------------------

This Belden CAT5 has:
MHz Loss @ 100 meters
1.000 2.000
4.000 4.100
8.000 5.800
10.000 6.500
16.000 8.200

The loss at 4 MHz is 1.5 dB less at 328.08 feet.
http://www.belden.com/techdatas/english/1583a.pdf

<http://www.belden.com/pdfs/techinfo/DS_D_Inside_Horizontal_Cable.pdf>

-----------------------------------------

[Cydrome Leader]

klem kedidelhopper <captainvi...@gmail.com> wrote:

> On Jan 8, 1:40?pm, Cydrome Leader <prese...@MUNGEpanix.com> wrote:
>> klem kedidelhopper <captainvideo462...@gmail.com> wrote:
>> > We need to run video over some existing CAT5 cables using baluns on
>> > either end. The existing cables are all terminated with jacks on both
>> > ends. One end is a patch panel and on the other end they are connected
>> > to jacks which are mounted on the baseboards. We plan to make 8 foot
>> > cables with an RJ 45 on one end, plug it into the baseboard jack, run
>> > the cable up the wall and then connect the other end to the balun and
>> > then to the camera. Would it matter if this short piece of cable were
>> > CAT3? Thanks, Lenny
>>
>> why would you use cat3? Also where do you even get cat3 unless you're a
>> copper thief these days?
>>
>> I'd use silver satin, or some 1980s 50 foot coiled kitche telephone cords,
>> with a handset swivel thingy on it, with nothing but the finest and most
>> reasonably priced rj11 to rj45 adapters from Black Box.
>
> Well the obvious reason to use CAT 3 is because as a former telephone
> systems contractor I happen to have a shit load of it and I didn't

well hell, use some double cotton covered wire then.

> want to have to buy any additional CAT 5 at this time. Was that so
> difficult to figure out? Most people that visit this group are not

It was foolish for me to to assume most people have bought cable in the
past 20 years.

[klem kedidelhopper]

The cable I have comes from various sources. No big name brands so
figuring exact losses would be difficult however the Belden specs are
eye openers. Thanks Michael for posting those. Lenny

[William Sommerwerck]

I can't blame anyone for not wanting to spend money if they don't have to.
(I'm no different.) But isn't it time to "knuckle down, buckle down, do it, do
it, do it"?

[Plai...@yawhoo.com]

Sometimes there are so many variables that the only thing to do is TRY
IT!!! There is no obvious reason it won't work, but there is also no
way to guarantee it WILL work.

Understanding theory is all well and good. Applying it properly is
another thing. In the final test, the emperical results are what
counts.

One story goes that Thomas Edison assigned a simple task to a newly
hired engineer - calculate the volume of a light bulb. The newbie
measured the bulb at the points he felt were critical and spent the
afternoon calculating the volume. Edison looked at the numbers and
said "You're off by at least 10%". Edison then took the light bulb,
drilled a little hole in it, filled it with water, then drained the
water into a graduated cylinder. And showed the engineer his numbers
were off by 10%.

PlainBill

[tuinkabouter]

But Edison measured the inside volume. The engineer calculated the
outside volume. To proof this, the engineer submerges the light bulb
and measured the water rise.
To prove his measurement he measured the force to keep it submerged.

So he proved that Edison was wrong.
The glass of the bulbs in those times was very thick.

[William Sommerwerck]

> One story goes that Thomas Edison assigned a simple task to a newly
> hired engineer - calculate the volume of a light bulb. The newbie
> measured the bulb at the points he felt were critical and spent the
> afternoon calculating the volume. Edison looked at the numbers and
> said "You're off by at least 10%". Edison then took the light bulb,
> drilled a little hole in it, filled it with water, then drained the
> water into a graduated cylinder. And showed the engineer his numbers
> were off by 10%.

But Edison measured the inside volume. The engineer calculated the
outside volume. To proof this, the engineer submerges the light bulb
and measured the water rise.
To prove his measurement he measured the force to keep it submerged.

So he proved that Edison was wrong.
The glass of the bulbs in those times was very thick.

You're missing the point of the story. There are ways to measure things that
are quick and elegant -- rather than applying a brute-force approach.

[klem kedidelhopper]

On Jan 11, 5:49 pm, "William Sommerwerck" <grizzledgee...@comcast.net>
wrote:

The hole in the bulb was pretty slick. So was the water for that
matter. I picked up a couple of baluns today and I am TRYING it
tomorrow, CAT3, CAT 5, Coax, etc. and I'll let you guys know. Thanks
for everyone's input. I really do appreciate it. Lenny

[tuinkabouter]

No. Edison asked the engineer: "calculate the volume of a light bulb".
He did not ask to measure it.

Edition should have asked: "what is the inside volume of this light
bulb". Then the engineer could decide to use other physical means to get
the right answer.

Don't mess with engineers.

[William Sommerwerck]

>> You're missing the point of the story. There are ways to measure things
>> that are quick and elegant -- rather than applying a brute-force approach.

> No. Edison asked the engineer: "calculate the volume of a light bulb".
> He did not ask to measure it.

So why did Edison make the guy look like a fool?

[Michael A. Terrell]

tuinkabouter wrote:
>
> On 1/11/2013 11:49 PM, William Sommerwerck wrote:

> ?? One story goes that Thomas Edison assigned a simple task to a newly
> ?? hired engineer - calculate the volume of a light bulb. The newbie
> ?? measured the bulb at the points he felt were critical and spent the
> ?? afternoon calculating the volume. Edison looked at the numbers and
> ?? said "You're off by at least 10%". Edison then took the light bulb,
> ?? drilled a little hole in it, filled it with water, then drained the
> ?? water into a graduated cylinder. And showed the engineer his numbers
> ?? were off by 10%.
> ?
> ? But Edison measured the inside volume. The engineer calculated the
> ? outside volume. To proof this, the engineer submerges the light bulb
> ? and measured the water rise.
> ? To prove his measurement he measured the force to keep it submerged.
> ?
> ? So he proved that Edison was wrong.
> ? The glass of the bulbs in those times was very thick.
> ?
> ?
> ? You're missing the point of the story. There are ways to measure things
> ? that are quick and elegant -- rather than applying a brute-force approach.

>
> No. Edison asked the engineer: "calculate the volume of a light bulb".
> He did not ask to measure it.
>
> Edition should have asked: "what is the inside volume of this light
> bulb". Then the engineer could decide to use other physical means to get
> the right answer.

Did Edision remove the support stem that took up part of the voulume,
or is this just another urban legend?

> Don't mess with engineers.

What railroad do you work for?

[Leif Neland]

William Sommerwerck frembragte:

That's the perogative of the boss/mentor/idol, to make the little guy
look like a fool even if he is right.

Leif

--
Husk kￜrelys bagpￜ, hvis din bilfabrikant har taget den idiotiske
beslutning at undlade det.

[William Sommerwerck]

>>>> You're missing the point of the story. There are ways to measure things
>>>> that are quick and elegant -- rather than applying a brute-force
>>>> approach.

>>> No. Edison asked the engineer: "calculate the volume of a light bulb".
>>> He did not ask to measure it.

>> So why did Edison make the guy look like a fool?

> That's the perogative of the boss/mentor/idol, to make the little guy look
> like a fool even if he is right.

Okay. But you're still taking the wrong lesson from the story.

I've never liked Edison. There's no question that he was an idiot, and a POS.
There's the story that he hired the then-reputationless Tesla to re-engineer
his generator design, promising him $50,000 for the work. When the work was
done, he refused to pay Tesla, saying "You have a lot to learn about American
business practice".

[klem kedidelhopper]

On Jan 13, 9:27 am, "William Sommerwerck" <grizzledgee...@comcast.net>
wrote:

Employers like that are the reason I've been self employed for the
last 30 years. Lenny