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Discussion Starter · #1 ·
I thought it would be a big help to many if there is a tip thread for HDMI over Cat5/6. Maybe a sticky if enough information gets accumulated here.


Ok here's my dilemma.


I have all monoprice stuff, its cheap, but it should work as advertised.


Setup:


All source components in a media closet run to 4x4 matrix switch-then to HDMI over Cat5 baluns-to patch panel-over Cat5e-to Receiver Balun-to Pioneer Elite VSX-03-TXh-to Panasonic G10 Plasma.


All HDMI cables are 24 awg wires, intermediate cables are Cat6, while structured wiring is Cat5e.


I have handshake issues with Directv intermittently, especially when I flip on or off recessed lighting.


PS3 will not complete handshake at all.


Xbox360 very flaky, sparklies, drops out instantly.


Question: Do HDMI extenders help? It seems like the hdmi signal is too weak when it gets to the end components. Is there any way to "boost" the signal?


Feel free to post ANY suggestions, someone might be able to use them if I cant.


Please HELP!!!1
 

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Seems to me that the 'cheaper' baluns may have more intermittent problems based upon reading many threads in this forum.


Tips:

#1) Use the highest bandwidth cable available for baluns, Cat6 if possible.

#2) Use proper connectors and tools to make cable terms

#3) Choose the best baluns and switching equipment within your budget....I know this is hard to accomplish


....others with more experience can add more.
 

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Discussion Starter · #3 ·
I think my problem might be the 5v on the HDMI not being robust enough to run the baluns.


I noticed dropout on the Directv when I turned the recessed lighting off and on, maybe this voltage drop could be the culprit?
 

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Discussion Starter · #4 ·
One hour with Monoprice "Tech Chat" aaaaaaaaand........


"Compatibility with HDMI switches is rarely a one to one issue. A device that is compatible with a particular switch may work fine when the switch is connected to one display or A/V receiver, but not function correctly when the switch is connected to a different model of TV or receiver. So depending on what is connected, results can vary and since possible combinations are almost infinite it's impossible to predict what the outcome will be until you try it."


HDMI is Garbage.
 

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HDMI is fine. Some HDMI produts are garbage. But then what would you expect from cheap crap from China?
 

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HDMI is fine. Some HDMI produts are garbage. But then what would you expect from cheap crap from China?


Also, keep in mind you are really complaining about your own engineering skills. There is a specification for a HDMI cable. It is not the same as Cat 5 or Cat 6. When you substitute, you are the engineer. Do you know the differences and how they can affect the signal?
 

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monoprice is great for buying things on the cheap.


However, when it comes to products like HDMI over Cat products, you get what you pay for.


Also, use Cat 6A STP or F/UTP. Increased bandwith and others have said that switching to a shielded cable has solved some of their problems.
 

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Quote:
Originally Posted by Magnus_Dx /forum/post/18169828


...others have said that switching to a shielded cable has solved some of their problems...

...as might be expected considering HDMI cable is shielded.
 

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Quote:
Originally Posted by NicksHitachi /forum/post/18166211


I think my problem might be the 5v on the HDMI not being robust enough to run the baluns.


I noticed dropout on the Directv when I turned the recessed lighting off and on, maybe this voltage drop could be the culprit?

No, the interference from the switch caused the dropout. If the 5V went low, it would have caused the device supplying it to die, and would be proof that that device was very poorly designed.

Quote:
...as might be expected considering HDMI cable is shielded.

HDMI uses differential signalling, shielding doesn't really matter.
 

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Quote:
Originally Posted by duvetyne /forum/post/18170779


HDMI uses differential signalling, shielding doesn't really matter.

Then why are the pairs shielded, to drive up the cost?
 

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But apparently this is unnecessary because you say the shielding doesn't matter. So why is it in the specification? The specification already has performance specifications for impedance. Similar specifications are already being met for UTP for data applications. Seems like adding the capacitance of the shield would not be the best approach to maintaining impedance at these data rates, not to mention the fact that inconsistent distance between shield and data pair can make impedance less consistent.


Differential-mode signalling is good but it is not a panacea. It depends on a lot of things being just right. Any deviation in a number of parameters affects its effectiveness. Effective shielding doesn't give you an advantage in difficult environments like long runs when intra-pair skew becomes a problem and makes differential-mode signalling less effective? Doesn't it help to minimize FEXT which is supposed to be up there with intra-pair skew as a potential problem?
 

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Quote:
Originally Posted by duvetyne /forum/post/18171354


To maintain a constant impedance...like most shielded twisted pairs.

The characteristic impedance of any cable, coaxial or twisted pair, is a function of the size (diameter) of the conductors, their spacing from each other, and the dielectric constant of any material around them (air, foam, PVC, etc.). Shielding can affect the characteristic impedance, but it is not there to maintain a constant impedance. Its main function is to shieldwhatever is enclosed from outside EMF (interference).


If the cable is unbalanced, as in the case of coaxial cable, the shield is also usually the return path/counterpoise for the center conductor signal (we'll not go into triaxial cables here), and by definition has to be there. If the cable is balanced, e.g. twisted pair, AND is fed from a truly balanced driver and ends in a device with a truly balanced (differential) input, the shield is seldom necessary as the diferential input will reject any common mode interference such as hum or RFI.


In very hostile environments, shielding a twisted pair may help reduce the amplitude of common mode interference, but a well designed front end would probably make the shielding redundant. OTOH if either the source or destination is not truly balanced,then all bets are off. Twisted pairs can be used to carry unbalanced signals, but you don't get the benefit of the common mode rejection of a balanced out/in. In this case, where twisted pairs are forced into a non-standard use, the shield may help.


Example: it is possible to connect an unbalanced analog audio output as is usually found on an RCA jack to a twisted pair, as perhaps in a Cat5/6 cable, to a device with an unbalanced RCA input (e.g. receiver sub out to subwoffer in) and it may work, but the risk of 60 Hz hum pickup is so great that it is unlikely. A shielded coaxial cable (by definition unbalanced) is a better choice.


HTH


Mike
 

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Quote:
The characteristic impedance of any cable, coaxial or twisted pair, is a function of the size (diameter) of the conductors, their spacing from each other, and the dielectric constant of any material around them (air, foam, PVC, etc.). Shielding can affect the characteristic impedance, but it is not there to maintain a constant impedance. Its main function is to shieldwhatever is enclosed from outside EMF (interference).

In a coax cable, the shield is the 'other conductor, the spacing between the center conductor and shield must be maintained to keep the characteristic impedance constant along the length of the cable.

we should all know by now that a foil or braided shield cannot 'shield' against electromagnetic interference.

Quote:
(we'll not go into triaxial cables here),

Why not? This forum constantly parrots myths about cables.

Quote:
the shield is seldom necessary as the diferential input will reject any common mode interference such as hum or RFI.

That's what I posted above but I was 'corrected' and told that the shield is what rejects electromagnetic interference.
 

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Let me restate my understanding of differential-mode signalling and the question. The noise rejection when using differential-signalling depends on having a truly balanced line (same impedance and length for both wires) and the common mode rejection of the receiver. Is that correct? No cable is perfect. There is going to be some intra-pair skew and some difference in impedance. If the intra-pair skew is too much (on the order of picoseconds), even if there is no noise, we have a problem. Likewise, although noise may be induced into both wires a some point, because of intra-pair skew, when it gets to the receiving end, it doesn't necessarily get there at the same time on both wires, or at the same amplitude because of impedance differences. The differential-mode receiver therefore does not entirely remove the noise from the signal. Is that correct? So, shielding still has no benefit in a difficult environment?
 

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Quote:
Originally Posted by Colm /forum/post/18168110


what would you expect from cheap crap from China?

These are the sort of ignorant quote i don't like.. Most "mass produced" electronics nowadays are made in china.. even some of your best brands cable company have factories in china. an item from china doesn't always mean is "chea and crap"


Now coming back to the issue at hand, all i can say is, "you get what you pay for" yeah i know same old quote.When dealing with HDMI is always best to get the best quality if budget allows.
 

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That is the kind of cheap rhetorical statement I would expect from someone like you. Attack the messenger instead of the message. You are the one who is ignorant if you don't know that there is a lot of cheap crap coming out of China.


Obviously, decent stuff can be made in China or anywhere else if the appropriate engineering, processes and quality control are applied. All the major electronics manufacturers have plants in China. However, Chinese companies are famous for cutting corners at the expense of quality and safety. Where else in the world have you heard of milk being contaminated with melanin? Guess how the recall went. The companies resold it to other companies that repackaged it and put it back on the market. Chinese companies are also famous for cutting corners on things like category cable by undersizing wires and not meeting flamability requirements. Do you watch the news? How about childrens' toys with high levels of heavy metals. There is a lot of cheap, Chinese crap on the market.
 

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Discussion Starter · #18 ·
Update: I am having better performance with higher ga. cable. Hopefully I can get the PS3 to complete handshake once the shorter thick HDMI gets here.


Quote:
Originally Posted by Colm /forum/post/18168110


HDMI is fine. Some HDMI produts are garbage. But then what would you expect from cheap crap from China?


Also, keep in mind you are really complaining about your own engineering skills. There is a specification for a HDMI cable. It is not the same as Cat 5 or Cat 6. When you substitute, you are the engineer. Do you know the differences and how they can affect the signal?

Your right, I'm not an engineer, and never had to be using other formats prior to HDMI. The fact that you have to be to use it is why I characterize it as Garbage. Even the best most expensive manufacturers of HDMI equipment have abundant problems. I love what it does when it works, one cable solution, high bandwidth, but when it does not I want to pull my hair out.....
 

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Good to hear you are having some success. Yes, HDMI can be frustrating if you try to push it beyond its inherent capabilities. HDMI wasn't designed to run the distances that many of us would like to run it over a passive cable. There are a lot of tradeoffs in the design. If the designers had chosen to use coaxial cable instead of twisted-pair, or chosen a different encoding method, distance might not be as big a problem. But we would probably be complaining about other things. The limited distance capability of a passive HDMI cable and the lack of field termination capability has lead to a plethora of products designed to get around the limitations. The good ones work well up to reasonable distances but are relatively expensive. That leaves an opening for the cheap, crap products that often seem to promise a solution they cannot deliver. That leaves the buyer playing engineer.
 

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Discussion Starter · #20 ·
Update:


I can complete handshake with all devices over baluns without the 4x4 matrix switch in the loop.


I contacted monoprice and they are going to send me a new one. Its a longshot, but I'm hoping this one(switch) is defective. The switch is powered so the the signal shouldn't be degraded right?


The HDMI light on the AVR blinks more rapidly and intermittently when the switch is installed. When its not installed the switch blinks strong a couple times and goes solid(good signal) or just goes solid automatically.


If the new switch doesn't work whats next??????????
 
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