Troubleshooting Channel Vision IR-Over-Coax

[Rob Ivy]

Hello everyone. I'm looking for some assistance from those of you
running an IR-over-coax system in your home.

Here's a summary of my setup: I have Cat6 and coax home run from each
room in my house back to a rack in my laundry room. I'm routing cable
plus modulating 2 Tivos through a Channel Vision CVT2/8-PIA II
amplified splitter to 5 TVs. I have a Channel Vision IR-4000 engine
attached to one of the 3 unused outputs on the splitter, and I have
Channel Vision IR-4100 receivers on 4 of the 5 TVs. I'm using Channel
Vision IR-2105 targets plugged into the IR-4100s. I have DC blockers
on the 2 unused outputs on the splitter, the 5th TV, and the cable
input to the splitter. This setup is exactly as depicted in the
channel vision literature.

Here's the problem: When any 2 of the IR-2105 targets are plugged in,
everything works just fine. I can control my Tivos remotely from
those 2 TVs with no problems. However, when I plug in the third
IR-2105 target, the response becomes spotty. Some signals get through
but most don't. When all four IR-2105s are plugged in, there is no
response whatsoever from any of the 4 locations. I know that the DC
is passing to all the targets, because the bright blue indicator bulb
lights brightly when they receive IR, yet the IR is not making it back
to the engine.

My only thought (and I'm no expert on any of this so this is just
speculation) is that perhaps there is a limit to how much distance the
DC can travel without weakening to the point where it can no longer
carry the IR signal. My four coax runs where the IR-4100s are
located are of approx 40ft, 50ft, 120ft, and 120ft, respectively.
Perhaps the single 12V DC input to the IR-4000 doesn't have the
horsepower necessary? The Channel Vision instructions state that 4
IR-4100s can be run off of a single engine, and that the max distance
to the engine is 500ft, however it doesn't say if that is 500 feet in
aggregate or each individual run.

Any help/thoughts/advice is MUCH appreciated, as this is driving me
nuts. Many thanks in advance. -Rob

[Robert Green]

"Rob Ivy" <robivy@comcast.net> wrote in message
news:1174260203.998667.261540@e1g2000hsg.googlegro ups.com...
> Hello everyone. I'm looking for some assistance from those of you
> running an IR-over-coax system in your home.

First thing to do would be to try to get hold of their tech support.

> Here's a summary of my setup: I have Cat6 and coax home run from each
> room in my house back to a rack in my laundry room. I'm routing cable
> plus modulating 2 Tivos through a Channel Vision CVT2/8-PIA II
> amplified splitter to 5 TVs. I have a Channel Vision IR-4000 engine
> attached to one of the 3 unused outputs on the splitter, and I have
> Channel Vision IR-4100 receivers on 4 of the 5 TVs. I'm using Channel
> Vision IR-2105 targets plugged into the IR-4100s. I have DC blockers
> on the 2 unused outputs on the splitter, the 5th TV, and the cable
> input to the splitter. This setup is exactly as depicted in the
> channel vision literature.
>
> Here's the problem: When any 2 of the IR-2105 targets are plugged in,
> everything works just fine.

Which two? Your 120' runs or the two shorter runs?

> I can control my Tivos remotely from
> those 2 TVs with no problems. However, when I plug in the third
> IR-2105 target, the response becomes spotty. Some signals get through
> but most don't. When all four IR-2105s are plugged in, there is no
> response whatsoever from any of the 4 locations. I know that the DC
> is passing to all the targets, because the bright blue indicator bulb
> lights brightly when they receive IR, yet the IR is not making it back
> to the engine.

Have you taken a DC voltmeter to various points on the cable? That might
tell you if you've got too much of a voltage loss.

> My only thought (and I'm no expert on any of this so this is just
> speculation) is that perhaps there is a limit to how much distance the
> DC can travel without weakening to the point where it can no longer
> carry the IR signal. My four coax runs where the IR-4100s are
> located are of approx 40ft, 50ft, 120ft, and 120ft, respectively.
> Perhaps the single 12V DC input to the IR-4000 doesn't have the
> horsepower necessary? The Channel Vision instructions state that 4
> IR-4100s can be run off of a single engine, and that the max distance
> to the engine is 500ft, however it doesn't say if that is 500 feet in
> aggregate or each individual run.
>
> Any help/thoughts/advice is MUCH appreciated, as this is driving me
> nuts. Many thanks in advance. -Rob

I would try covering all but one of the receivers at a time, with all four
connected. With IR setups it's very possible that stray IR light is
overwhelming the system. One way to check for that is to cover up the
receivers, test, then eventually remove the other three covers, one at a
time. It might be helpful to cover them with metal cans while testing. IR
receivers can often pick up stray EMI if the source is close enough. IR
receivers are typically located near strong EMI sources like TV's.

--
Bobby G.

[Rob Ivy]

Thanks for the reply Bobby. Here are my thoughts on your thoughts:

> First thing to do would be to try to get hold of their tech support.

Yep...I've been working with them but was hoping for a second opinion
from this group -perhaps someone had already encountered the same
issue.

> Which two? Your 120' runs or the two shorter runs?

Any 2 runs - both 120' runs work if it's just those 2, or any
combination of 2.

> Have you taken a DC voltmeter to various points on the cable? That might
> tell you if you've got too much of a voltage loss.

That's my next step, and also recommended by CV tech support. I've
also ordered a line tester to see if I have a short somewhere.
Hopefully it's one of those 2 things - then I'll have the issue of
fixing it, but at least I'll know what the problem is.

> I would try covering all but one of the receivers at a time, with all four
> connected. With IR setups it's very possible that stray IR light is
> overwhelming the system. One way to check for that is to cover up the
> receivers, test, then eventually remove the other three covers, one at a
> time. It might be helpful to cover them with metal cans while testing. IR
> receivers can often pick up stray EMI if the source is close enough. IR
> receivers are typically located near strong EMI sources like TV's.

Good advice. These targets are supposed to be sheilded (they should
be - for $55 a piece), but that's good advice. If I don't have any
shorts and the voltage checks out, I'll stick each target in an
aluminum can one at a time.

I should know something by the weekend - will post back with the
findings to complete the thread for future reference.

Thanks for taking the time to reply. -Rob

[Slammer]

"Rob Ivy" <robivy@comcast.net> wrote in message
news:1174260203.998667.261540@e1g2000hsg.googlegro ups.com...
> My only thought (and I'm no expert on any of this so this is just
> speculation) is that perhaps there is a limit to how much distance the
> DC can travel without weakening to the point where it can no longer
> carry the IR signal. My four coax runs where the IR-4100s are
> located are of approx 40ft, 50ft, 120ft, and 120ft, respectively.
> Perhaps the single 12V DC input to the IR-4000 doesn't have the
> horsepower necessary? The Channel Vision instructions state that 4
> IR-4100s can be run off of a single engine, and that the max distance
> to the engine is 500ft, however it doesn't say if that is 500 feet in
> aggregate or each individual run.
>
> Any help/thoughts/advice is MUCH appreciated, as this is driving me
> nuts. Many thanks in advance. -Rob

It sounds like a voltage drop problem. What size coax did you run?
The trouble with Channel Vision specs is they don't specify conductor
size when stating 500ft runs. My calcs suggest #14 AWG is appropriate
such as Belden 1523A RG11 Broadband Cable.

Baring this, I would replace the IR-4000 and/or it power supply then
the splitter.

Hope this helps,

Michael

[Robert Green]

"Rob Ivy" <robivy@comcast.net> wrote in message
news:1174416302.782329.108720@l77g2000hsb.googlegr oups.com...
> Thanks for the reply Bobby. Here are my thoughts on your thoughts:
>
> > First thing to do would be to try to get hold of their tech support.
>
> Yep...I've been working with them but was hoping for a second opinion
> from this group -perhaps someone had already encountered the same
> issue.

Good. I sometimes forget the basics myself and it's always useful to report
the problem so that they at least have a shot at it! (-:

> > Which two? Your 120' runs or the two shorter runs?
>
> Any 2 runs - both 120' runs work if it's just those 2, or any
> combination of 2.

That sounds very much like a voltage drop problem. If you had a problem
sensor, it would present differently. Whenever it was included in a
combination of two, it should cause the whole IR net to fail. Apparently,
it doesn't.

> > Have you taken a DC voltmeter to various points on the cable? That
might
> > tell you if you've got too much of a voltage loss.
>
> That's my next step, and also recommended by CV tech support. I've
> also ordered a line tester to see if I have a short somewhere.
> Hopefully it's one of those 2 things - then I'll have the issue of
> fixing it, but at least I'll know what the problem is.

Let us know what you find. Michael's comment about wire size is probably
the real key here. What kind of cable are you using?

> > I would try covering all but one of the receivers at a time, with all
four
> > connected. With IR setups it's very possible that stray IR light is
> > overwhelming the system. One way to check for that is to cover up the
> > receivers, test, then eventually remove the other three covers, one at a
> > time. It might be helpful to cover them with metal cans while testing.
IR
> > receivers can often pick up stray EMI if the source is close enough. IR
> > receivers are typically located near strong EMI sources like TV's.
>
> Good advice. These targets are supposed to be sheilded (they should
> be - for $55 a piece), but that's good advice. If I don't have any
> shorts and the voltage checks out, I'll stick each target in an
> aluminum can one at a time.

I'd concentrate my effort on looking for a voltage drop so severe that the
electronics stop functioning. It may take an amplifier to correct, as
suggested. The fact that any two work but more don't really points to a
systemic problem rather than a failed or erratic component.

> I should know something by the weekend - will post back with the
> findings to complete the thread for future reference.

Great. Appreciate the feedback.

> Thanks for taking the time to reply. -Rob

I'm surprised so few others did. Oh well.

--
Bobby G.

[Slammer]

> Have you taken a DC voltmeter to various points on the cable? That might
> tell you if you've got too much of a voltage loss.
>
> --
> Bobby G.

Rob, I would like to add that even with a voltage drop, you may still read
12VDC when you measure the voltage at any TV unless the circuit is loaded.
Attach three of the IR-4100's with their IR-2105's and then measure across
the fourth output at the TV.

Additionally, check and make sure all your connections are good, the crimps
are solid and the braids are dressed.

Lastly, there is always the possiblity that one of the terminators is bad,
i.e., leaking DC voltage since this splitter is a pass-thru device but that
would be my last resort.