Cat5 experiment
Douglas Tourtelot
video village and the sound cart on my last picture. Boy did it work
great!! It made me rethink the whole idea and knocked my video transmitter
on the head in terms of ease vrs. quality. The only weakness was in the
durability of the cable (even at the extremely cheap cost of replacement).
The ends were severed pretty easily, although two 100' runs got me through
the whole project; lost the second end an hour before the movie wrapped<g>.
And replacement ends are "a-dime-a-dozen." I just ordered some "tactical"
grade cable from Gepco along with the Neutrik system of Cat5 connectors;
I'll report back but that should go a long way to prevent the re-ocurance of
that problem.
D.
terr...@mindspring.com
What hardware did you use? (besides the cable)
David Terry
Douglas Tourtelot
are pretty simple.
D.
<terr...@mindspring.com> wrote in message
news:1158697954.4...@m7g2000cwm.googlegroups.com...
Peter
has the RJ45s. I have considered gutting the balun but haven't looked
inside to see how easy that would be.
Peter
s...@simonbishop.com
find us a clue at some point please Doug?
Kindest regards,
Simon B
Douglas Tourtelot
the appropriate connectors mounted. Should be pretty easy, although I
haven't opened mine up yet. At the cart, the Neutrik pass-through will jump
to the balun already mounted on a short Cat5 jumper.
D.
"Peter" <pkur...@earthlink.net> wrote in message
news:1158703244....@b28g2000cwb.googlegroups.com...
Douglas Tourtelot
D.
<s...@simonbishop.com> wrote in message
news:1158704510.1...@m7g2000cwm.googlegroups.com...
Douglas Tourtelot
too.
http://www.muxlab.com/products/ve_avd_2w_av_balun.html
D.
"Douglas Tourtelot" <tour...@nospanspeakeasy.net> wrote in message
news:MoGdnZW4afqJ6I3Y...@speakeasy.net...
Peter
I'm using ETS PV905 baluns which allow 2
independent video lines (BNC) and 2 RCAs at each end. I think Phillip
Palmer said he used the Intellix ones.
Peter
Phillip W. Palmer, C.A.S.
s...@simonbishop.com wrote:
> I too would be most interested in the baluns hardware used. > Kindest regards,
>
> Simon B
I've been using the same system for this season of Jericho, about 10
weeks now and. I've got a couple of 100' lengths and a couple of 50'
lengths, probably some 25' as well. I just couple them together when I
get too far away....works great!
The baluns that I use are:
http://sewelldirect.com/Intelix-AV-Balun-4-RCA-to-RJ45.asp
I bought a box of stranded CAT 5 cable, a crimper and a stripper.
That's all you need. Make sure you get stranded, as the solid core
doesn't wrap very well.
Phillip W. Palmer, C.A.S.
> weeks now and. I've got a couple of 100' lengths and a couple of 50'
> lengths, probably some 25' as well.
I somehow hit "post" before I finished one sentence....must be the
cookies at craft service.
I've been using it for about 10 weeks and have only had one RJ45
connector get crunched. A quick fix and it was back in business.
Douglas Tourtelot
D.
"Phillip W. Palmer, C.A.S." <ph...@palmeraudio.net> wrote in message
news:1158709990.5...@d34g2000cwd.googlegroups.com...
G. John Garrett, C.A.S
Yup, and you can run analog and AES audio down it all day. Turns out the
characteristic impedance is about 100 ohms.
John
asylum sound
audio into them?
Douglas Tourtelot
still good.
D.
"asylum sound" <asylu...@verizon.net> wrote in message
news:1158887034....@b28g2000cwb.googlegroups.com...
s...@simonbishop.com
How do they work?
It seems like magic to me!
Kindest regards,
Simon B
Richard Crowley
> So, does anyone know what is inside them?
> How do they work?
> It seems like magic to me!
The passive ones use transformers.
In the case of video, pretty broadband transformers,
but relatively simple (several turns, ferrite core, etc.)
They are actually not that much different from the
coax-to-twinlead antenna baluns you can buy for $1
The active ones use balanced driver/receiver chips
purpose-designed for that application. For example:
http://para.maxim-ic.com/cache/en/results/4893.html
You can see that these chips are rather inexpensive.
Jay Rose
> It seems like magic to me!
The magic is balancing, and because there are so many computers in the
world, well-balanced computer cable is cheap.
Details on the magic? http://www.dplay.com/dv/balance
--
Jay Rose CAS
tutorials and other sound goodies at dplay.com
email is "jay@" plus the dot-com in the previous line.
Jeff Wexler
s...@simonbishop.com wrote:
The part I don't understand is how a simple multi-conductor cable, the
typical Cat 5 configuration, is not subject to problems we try and solve
with good, well designed shielded traditional mic cable. Particularly
with long runs we need to concern ourselves with induced hum,
interference, broken or inadequate shielding, etc. Can someone explain
these things?
- Jeff Wexler
Eric Pierce
Mainly, it's the 1:1 ratio of level. Well designed, shielded microphone
cable carries microphone level signals which need to be amplified
40-60db along with any rf or any other electrical energy that can sneak
in. We've been sending line level balanced audio over many miles of
dedicated copper phone lines for decades now!
Eric Pierce
Richard Crowley
> s...@simonbishop.com wrote:
>
>> So, does anyone know what is inside them?
>> How do they work?
>> It seems like magic to me!
>> Kindest regards,
>>
>> Simon B
>
> The part I don't understand is how a simple multi-conductor cable, the
> typical Cat 5 configuration, is not subject to problems we try and solve
> with good, well designed shielded traditional mic cable. Particularly
> with long runs we need to concern ourselves with induced hum,
> interference, broken or inadequate shielding, etc. Can someone explain
> these things?
A simple/simplistic answer might be that the experiments
people are talking about here all deal with line-level, not
mic-level signals. And they all deal with secondary (i.e.
monitoring) use rather than the primary (recording) path.
This applies to both audio and video.
I look it as just a modern incarnation of the traditional
unshielded telephone line which we have been using
for ~100 years (and the source of our definition for
"line level", the 600-ohm traditional impedances, etc. :-)
Modern technology (ferrite magnetics and/or precision-
balanced IC circuitry) allows us to now send even non-
critical video over UTP.
The (new) thing that UTP ("Cat5", et.al.) brings to the
party is low-cost, precision balancing (tightly controlled
number of twists per inch, etc.) When combined with
good balancing/unbalancing circuitry at either end we
are now able to do things with cheap unshielded network
cable that we could not have imagined even 10 years ago.
I suspect that running square-wave timecode (or video)
along side mic level through UTP would be a problematic
as it sounds (no pun intended).
Douglas Tourtelot
video village. Just put together four pieces of Gepco Tactical Cat5 with
Neutrik HD (XLR style) ends. Very sweet.
D.
"Richard Crowley" <rcro...@xp7rt.net> wrote in message
news:4nj5bdF...@individual.net...
G. John Garrett, C.A.S
> On 2006-09-22 16:15:24 -0400, s...@simonbishop.com said:
>
>> It seems like magic to me!
>
>
> The magic is balancing, and because there are so many computers in the
> world, well-balanced computer cable is cheap.
>
> Details on the magic? http://www.dplay.com/dv/balance
And the current issue of the CAS quarterly
:-p
John
G. John Garrett, C.A.S
Cat 5 is comprised of multiple twisted pairs with grounds. Balancing and
pair-twisting take care of 95% or more of hum problems, and even though the
grounds do not provide a 100% electrostatic sheild, they do contribute to
protecting the pairs from interference! Maybe I can put up a link to some more
info, its late and I haven't had dinner yet :-p
John
Douglas Tourtelot
D.
"G. John Garrett, C.A.S" <j...@soundcartREMOVE.com> wrote in message
news:bfOdnUSH5ftHFInY...@comcast.com...
Richard Crowley
> Cat 5 is comprised of multiple twisted pairs with grounds. Balancing
> and pair-twisting take care of 95% or more of hum problems, and even
> though the grounds do not provide a 100% electrostatic sheild, they do
> contribute to protecting the pairs from interference! Maybe I can put
> up a link to some more info, its late and I haven't had dinner yet :-p
Note that most Cat5 cable is "UTP"
Un-shielded Twisted Pair
No shield, and no ground,
just 4 twisted pair.
Dave Liquorice
>> Cat 5 is comprised of multiple twisted pairs with grounds.
>
> Note that most Cat5 cable is "UTP"
> Un-shielded Twisted Pair
Aye, you can get shielded Cat5 "STP", but it is an single overall screen
and probably just foil rather than lapped or braided.
--
Cheers new...@howhill.com
Dave. pam is missing e-mail
Richard Crowley
> Richard Crowley wrote:
>> Note that most Cat5 cable is "UTP"
>> Un-shielded Twisted Pair
>
> Aye, you can get shielded Cat5 "STP", but it is an single overall
> screen
> and probably just foil rather than lapped or braided.
Right. I don't think there is any vairant where the pair
are shielded from each other. And the shielded ones
lack any kind of standardized connectorization for the
shield node.
Dave Morrison
the low cost and availability of Cat5 cable.
I even had a car stereo system (Denon) 3 or 4 years ago that used STP Cat5
between the head unit and the eq. Dead quiet.
dave
"Richard Crowley" <rcro...@xpr7t.net> wrote in message
news:12hbnu3...@corp.supernews.com...
Dave Liquorice
> I'm amazed that this method of signal transfer hasn't caught on more
> given the low cost and availability of Cat5 cable.
So am I TBH, especially for video feeds to the monitors used by make up
and cozzy etc. Coax is just such a pain to handle and get to lie sensibly
on the floor.
The only things I can see that people balk at it the cost of a pair of
baluns and the "fact" that video only connects via coax. Ordinary Cat5
isn't really robust enough for road use, neither are normal RJ45s but
both have those are not a problem any more. Neutrik have robust RJ45
connectors and suitably tough Cat5 is also available.
G. John Garrett, C.A.S
I'd be willing to give it a try. One cool thing about CATx cable is that the
pairs have different twist rates, to keep crosstalk between them down. I just
helped do a multi-studio install at a big FM station in Boston where every
analog device went into an A/D converter/node and all the nodes were connected
by gigabit switches. Everything had its on IP address and you can get to any
device from any room. Analog devices had their own connectors at the device, but
-everything- was CAT5. Slick, fast, good.
Check out:
http://www.studiohub.com/
Best,
John
John
Richard Crowley
Right. As long as everything is in the digital domain, no problem.
But I'd be wary of trying to run digital on one pair and analog
(particularly mic-level) on an adjacent pair.
The twist rates vary only ever so slightly to minimize the points
of contact between adjacent pair, but not enough to get very far
away from the impedance specification that must be maintained
to be certified as Cat5. This slightly varying twist is optimized
for low-crosstalk at RF frequencies (data rates), but not sure
how effective it would be at AF.
G. John Garrett, C.A.S
> "G. John Garrett, C.A.S" wrote...
>
>>Richard Crowley wrote:
>>
>>>"Jeff Wexler" wrote ...
>>>
>>>
>>>>s...@simonbishop.com wrote:
>>
>>>I suspect that running square-wave timecode (or video)
>>>along side mic level through UTP would be a problematic
>>>as it sounds (no pun intended).
>>
>>I'd be willing to give it a try. One cool thing about CATx cable is that
>>the pairs have different twist rates, to keep crosstalk between them down.
>>I just helped do a multi-studio install at a big FM station in Boston
>>where every analog device went into an A/D converter/node and all the
>>nodes were connected by gigabit switches. Everything had its on IP address
>>and you can get to any device from any room. Analog devices had their own
>>connectors at the device, but -everything- was CAT5. Slick, fast, good.
>
>
> Right. As long as everything is in the digital domain, no problem.
> But I'd be wary of trying to run digital on one pair and analog
> (particularly mic-level) on an adjacent pair.
I've wired at least two radio studios, all analog, with CAT5. I don't know as
I'd run digital on one pair and mic level analog on the other in the same jacket
either. The crosstalk between pairs is low, and there's no problem with adjacent
CAT5.
>
> The twist rates vary only ever so slightly to minimize the points
> of contact between adjacent pair, but not enough to get very far
> away from the impedance specification that must be maintained
> to be certified as Cat5. This slightly varying twist is optimized
> for low-crosstalk at RF frequencies (data rates), but not sure
> how effective it would be at AF.
High bandwidth data produces a bigger electromagnetic field than AF, so if its
good for RF its gooder for AF.
John
Jay Rose
<j...@soundcartREMOVE.com> said:
> High bandwidth data produces a bigger electromagnetic field than AF, so
> if its good for RF its gooder for AF.
Except low frequencies noises that RF can ignore can be a problem in
the AF world. There's wicked 60Hz hum, for example, on most CATV
systems.
Richard Crowley
> "G. John Garrett, C.A.S" said:
>
>> High bandwidth data produces a bigger electromagnetic field than AF, so
>> if its good for RF its gooder for AF.
>
> Except low frequencies noises that RF can ignore can be a problem in the
> AF world. There's wicked 60Hz hum, for example, on most CATV systems.
Well, they inject AC power directly onto the cable
to run all the amplifiers along the circuit. You can see
those pole-mounted transformers every mile or two
that tap the utility grid and inject power into the cable
system.
Jay Rose
>>
>> ...There's wicked 60Hz hum, for example, on most CATV systems.
>
> Well, they inject AC power directly onto the cable
> to run all the amplifiers along the circuit. You can see
> those pole-mounted transformers every mile or two...
Thanks, I didn't know that.
(If it were just 60 Hz, it would be tolerable. But the junk on a cable
goes all over the audio band. )
Richard Crowley
> "Richard Crowley" said:
>>> ...There's wicked 60Hz hum, for example, on most CATV systems.
>>
>> Well, they inject AC power directly onto the cable
>> to run all the amplifiers along the circuit. You can see
>> those pole-mounted transformers every mile or two...
>
>
> Thanks, I didn't know that.
>
> (If it were just 60 Hz, it would be tolerable. But the junk on a cable
> goes all over the audio band. )
The signal has likely passed through >1,000,000 transistors
before it reaches your house. It is a wonder that the signal
survives as well as it does with such ancient analog technology.
Douglas Tourtelot
than later<g>) I will try and run audio TC down one pair and see how bad the
cross-talk to adjacent pairs is. Easy to do and measure. I don't use my
baluns in that capacity but it would be good to know what the worst case
(and I think time code at -10 pretty much qualifies!) senario for cross-talk
would be. In my experience, two pair of NTSC video and two of nominal line
level do not any effect on each other.
D.
"Richard Crowley" <rcro...@xp7rt.net> wrote in message
news:4nvph6F...@individual.net...
Jay Rose
<tour...@nospanspeakeasy.net> said:
> Just for fun, when I get my rig out of storage next time (hopefully
> sooner than later<g>) I will try and run audio TC down one pair and see
> how bad the cross-talk to adjacent pairs is. Easy to do and measure.
> I don't use my baluns in that capacity but it would be good to know
> what the worst case (and I think time code at -10 pretty much
> qualifies!) senario for cross-talk would be.
Are you saying you'd send unbalanced timecode (no balun or
opamp/transformer code i/o) on Cat5? That's about as worst-case as a
signal could possibly get! Not to mention that you'd be tieing both
ends' grounds together, something that doesn't happen on a normal Cat5
link...
Douglas Tourtelot
D.
"Jay Rose" <see_s...@nowhere.com> wrote in message
news:2006092715220416807-seesigfile@nowherecom...
Billy Sarokin
My thanks to everyone for this thread. I got curious and ordered a
couple of baluns and a kit of 1000' Cat 5 with crimper and tester.
Everything arrived yesterday and I put it into service today. It's
GREAT!!! 2 audio feeds to the video guy and 2 video feeds in return.
I haven't used any cables in years, so wrapping cable will take some
getting used to, but this seems to be the simplest and easiest way to
get a quality video feed (and send audio). I wouldn't have known
about this if it weren't for RAMPS. So as I said, my thanks to
everyone!
Billy Sarokin
soundgun
feature, I built a system like this myself using Cat5. However, I
didn't use the Baluns (didn't know they existed) and made my own
breakout cables for each end. It carries stereo balanced to camera and
a stereo unbalanced signal back. It works OK, SOMETIMES. The feed to
camera has ALMOST always been clean, but my monitor feed often picks up
RFI from lighting. In one odd scenario, I was in the large, atrium
foyer on the first floor of a mansion (on Mulhulland) and the camera
was upstairs. I ran the cable straight up through the railing of the
walkway above me. How fascinating it was when I heard one of the
powerful transmitters nearby picked up a little too well by my Cat5
cable (antenna). Needless to say, I have a legit "beta snake" on
order. But using the system you describe for a tie to video village
sure beats flaky video feeds!
George Whittam
eldorec.com
Richard Crowley
> Needing to solve an audio to camera feed issue on a no budget HD
> feature, I built a system like this myself using Cat5. However, I
> didn't use the Baluns (didn't know they existed) and made my own
> breakout cables for each end. It carries stereo balanced to camera and
> a stereo unbalanced signal back. It works OK, SOMETIMES. The feed to
> camera has ALMOST always been clean, but my monitor feed often picks up
> RFI from lighting.
That seems consistent with what we would expect. Even without
impedance matching, balanced feeds would take advantage of
the good twisted pair technology of the UTP cable. And unbalanced
signals would be subject to environmental RFI, etc. since the "U"
in UTP stands for unshielded.
Noah Timan
Douglas Tourtelot wrote:
> Yes that's right. Line level sends to video village, video back to me from
> video village. Just put together four pieces of Gepco Tactical Cat5 with
> Neutrik HD (XLR style) ends. Very sweet.
Doug, have you continued to be happy with the Gepco cable for use in
the field? If so, can you please share the part number? I bought one
of those bulk stranded Cat5 kits but the cable seems flimsy and coils
poorly. I think something more akin to the cable strength and
flexibility that we normally use with Canare, etc is what's needed. If
the Gepco is that (or someone knows another alternate), please let us
know! Thanks.
Regards,
Noah Timan
Richard Crowley
I got samples of the two varieties of Belden's "tactical catsnake"
http://www.belden.com/01Home/01_FeaturedProduct.cfm
Seems pretty nice. The smaller one (1304A), ~ 1/4" diameter,
has the four Cat5e twisted pair moulded into a rubber-like
matte-black PVC jacket. The larger one (1305A) is more
like a "standard" Cat5e cable with the PVC jacket, and then
the rubber-like black outer jacket moulded over it. The smaller
one appears to handle (lay flat, roll up, etc.) more like "normal"
mic cable, but the larger one may be more rugged for heavy-
duty use. Both appear to be compatible with the Neutrik
EtherCon connectors.
Douglas Tourtelot
http://www.gepco.com/products/proav_cable/network/4pr_cat5Eheavyduty_M.htm
D.
"Noah Timan" <dontwrit...@yahoo.com> wrote in message
news:1164132779.3...@k70g2000cwa.googlegroups.com...
Billy Sarokin
my best to destroy it to no avail.. In one scene 2 1/2 ton army trucks
were rolling back and forth over it for hours. The cable never gave
up. Amazing.
Billy Sarokin
Phillip W. Palmer, C.A.S.
off ebay, and we've been using it for 5 months now on a TV series.
Cars, trucks, dollies, condors, you name it...it's run over it...and
It's still working fine. The cable that I bought is a tan color, and
totally by accident...it matches just about every exterior we shoot in.
I hardly ever have to re-route it when the village moves (which is
every shot almost).
Douglas Tourtelot
make sure that you take care of tieing off the cable so the ends don't get
pulled off, it should be pretty good to go. I had some sloppy days where
the ends got caught up in the wheels of my cart and I decided that
bomb-proofing was the key to less frustration at the cost of more money.
I'd rather be at crafty drinking capos than crimping on Cat5 connectors<g>.
D.
"Billy Sarokin" <big...@verizon.net> wrote in message
news:1164140468....@b28g2000cwb.googlegroups.com...
Douglas Tourtelot
D.
"Phillip W. Palmer, C.A.S." <ph...@palmeraudio.net> wrote in message
news:1164145392....@b28g2000cwb.googlegroups.com...
-弗ｦ*@le斧s.com ｰ､Rｼ斧�ｦ*b rtｰ�
<tour...@speakeasy.net> schreef:
>I find that the ends are the "weak link." Billy is right in that if you
>make sure that you take care of tieing off the cable so the ends don't get
>pulled off, it should be pretty good to go. I had some sloppy days where
>the ends got caught up in the wheels of my cart and I decided that
>bomb-proofing was the key to less frustration at the cost of more money.
>I'd rather be at crafty drinking capos than crimping on Cat5 connectors<g>.
>
>D.
What do you use as an begin/end part/translation to RCA or BNC ?
( the box at the end of the cable )
R ( looking forward to do some testing with this Cat5 )
Billy Sarokin
http://www.av-cables.net/baluns/baluns-v2a2.html
Billy
On Nov 21, 6:31 pm, °¤R¼•€•*¦*b€rt°•
<~¤-•¦-y¤€-•¤¦*@le•€s.com> wrote:
> >D.What do you use as an begin/end part/translation to RCA or BNC ?
Douglas Tourtelot
D.
"Billy Sarokin" <big...@verizon.net> wrote in message
news:1164154251.4...@m73g2000cwd.googlegroups.com...
> I'm using the AvoCat balun $79 each
> http://www.av-cables.net/baluns/baluns-v2a2.html
> Billy
>
> On Nov 21, 6:31 pm, °¤R¼.?.*¦*b?rt°.
Noah Timan
Douglas Tourtelot wrote:
> Here is a link to the Gepco part:
> http://www.gepco.com/products/proav_cable/network/4pr_cat5Eheavyduty_M.htm
Thank you, sire.
Do you like this Gepco cable? Does it wrap well and take abuse well?
Or are you with everyone else that the cheap stuff is good enough and
it's unnecessary?
I'm about to try it for the first time -- these were just first
observations. If the cheap stuff works, then obviously that's fine
(well, better than fine as now I have a 1000' box of it sitting
around). Just wanted a "Plan B" ready in case it became frustrating.
It does seem to have a hard time with over-under (or over-over for that
matter) but maybe it just needs to be "trained".
nvt
Noah Timan
Douglas Tourtelot wrote:
> Here is a link to the Gepco part:
> http://www.gepco.com/products/proav_cable/network/4pr_cat5Eheavyduty_M.htm
Thank you, sire.
Douglas Tourtelot
the Neutrik ends on it, seems to be nearly in-destructable. It is 1)
expensive and 2) way harder to terminate than the regular cable, but since I
made it for me and I get the labor for free, it seemed the correct way to
go. It lays flat (it is almost the consistancy of Belden mic-cable
(old-school)) and it over-unders beautifully. I have, in the past, gotten
the regular cat5 cable to behave after being stretched out in the sun on a
nice day and then over-undered. Still a little wonky, but no grips tripped
over it! The biggest problem I had was the ends getting pulled off; that
won't happen with the Gepco cable and the Neutrik covers. You'll pull the
jack out of the patchbay first!
D.
"Noah Timan" <dontwrit...@yahoo.com> wrote in message
news:1164161840....@j44g2000cwa.googlegroups.com...
-弗ｦ*@le斧s.com ｰ､Rｼ斧�ｦ*b rtｰ�
<tour...@speakeasy.net> schreef:
>Same.
And this is a passive ( not powered ) box ? Any problems with the
Video termination ( 50 Ohm or something ? ) so that you mess up , or
rather do not mess up the video signal ?
R
Douglas Tourtelot
un-balanced/balanced) there are 75 ohm transformers at both ends which
provide perfect termination. They really are fairly "magic."
D.
"°¤R¼.?.*¦*b?rt°." <~¤-.¦-y¤?-.¤¦*@le.?s.com> wrote in message
news:c858m2lu0k46g3daf...@4ax.com...
Dave Liquorice
> Yes, it is totally passive, and because of the nature of baluns (that
> is un-balanced/balanced) there are 75 ohm transformers at both ends
> which provide perfect termination. They really are fairly "magic."
110 ohms for cat 5
>
> D.
>
> "° R¼.?.* *b?rt°." <~ -. -y ?-. *@le.?s.com> wrote in message
> news:c858m2lu0k46g3daf...@4ax.com...
> > On Tue, 21 Nov 2006 16:14:42 -0800, "Douglas Tourtelot"
> > <tour...@speakeasy.net> schreef:
> >
> >>Same.
> >
> > And this is a passive ( not powered ) box ? Any problems with the
> > Video termination ( 50 Ohm or something ? ) so that you mess up , or
> > rather do not mess up the video signal ?
> >
> >
> > R
> >
> >
> >
> >
> >
> > --
> > Http://80.126.58.137/
>
>
--
Cheers new...@howhill.com
Dave. pam is missing e-mail
Douglas Tourtelot
other.
D.
"Dave Liquorice" <new...@howhill.com> wrote in message
news:nyyfbegfubjuvyypb...@srv1.howhill.com...
On Wed, 22 Nov 2006 07:18:32 -0800, Douglas Tourtelot wrote:
> Yes, it is totally passive, and because of the nature of baluns (that
> is un-balanced/balanced) there are 75 ohm transformers at both ends
> which provide perfect termination. They really are fairly "magic."
110 ohms for cat 5
>
> D.
>
> "° Rź.?.* *b?rt°." <~ -. -y ?-. *@le.?s.com> wrote in message
Noah Timan
Douglas Tourtelot wrote:
> Just for fun, when I get my rig out of storage next time (hopefully sooner
> than later<g>) I will try and run audio TC down one pair and see how bad the
> cross-talk to adjacent pairs is.
What did you find, if you did this? The idea of using CAT5 for an HD
feed is an interesting idea (2 audio sends, 1 TC send & 1 mono
headphone return). But it sounds like there might be too many
vulnerabilities. We'd also have to find baluns that processed four
audio signals, though I imagine that's probably not a complicated
search.
nvt
Richard Crowley
> What did you find, if you did this? The idea of using CAT5 for an HD
> feed is an interesting idea (2 audio sends, 1 TC send & 1 mono
> headphone return). But it sounds like there might be too many
> vulnerabilities. We'd also have to find baluns that processed four
> audio signals, though I imagine that's probably not a complicated
> search.
I understood from the dialog so far that people were using
it only for non-critical-path (i.e. monitoring) audio, not for
the primary camera feed (for example).
-弗ｦ*@le斧s.com ｰ､Rｼ斧�ｦ*b rtｰ�
<rcro...@xp7rt.net> schreef:
That's also the plan over here. For direct camera stuff we still have
the wonderful normal mic cable.
R
Douglas Tourtelot
been back with my gear since I wrote that, but will have time to experiment
after January.
D.
"Noah Timan" <dontwrit...@yahoo.com> wrote in message
news:1164236838.1...@f16g2000cwb.googlegroups.com...
Noah Timan
Richard Crowley wrote:
> I understood from the dialog so far that people were using
> it only for non-critical-path (i.e. monitoring) audio, not for
> the primary camera feed (for example).
That's how it's been used so far, yes. (And that's how I will also use
it for now). But it's an interesting idea to find a way to use it also
for critical application if those applications are similarly line level
or AES/EBU sends (ie camera feeds) as opposed to mic level sends (where
all the shielding and insulation is critical). A camera feed cable
that features eight pairs is a big, bulky, expensive cable and the
camera often needs to be several hundred feet away from the sound cart.
In addition to the need for extra cable, the extra length and camera
department inattentiveness often means the big, heavy, bulky,
difficult-to-solder multipin cable is VERY prone to damage. Having it
be an easy to build, disposable cable is an interesting idea -- if it
works. In the case of Cat5 it probably won't, but it's worth
investigating. Several of us have used fiber optic cable on HD jobs
with varying results -- the overall consensus seems to be that it's
"almost" there. I wonder out loud if this coudl be another option.
Regards,
Noah Timan
G. John Garrett, C.A.S
> On Wed, 22 Nov 2006 07:18:32 -0800, Douglas Tourtelot wrote:
>
>
>>Yes, it is totally passive, and because of the nature of baluns (that
>>is un-balanced/balanced) there are 75 ohm transformers at both ends
>>which provide perfect termination. They really are fairly "magic."
>
>
> 110 ohms for cat 5
+/- 20%, and on the -other- side of the transformer its 75 Ohms, at least as far
as the video goes.
John