Search results

Agreed, Peng. My younger brother is an EE, and he remembers studying transmission line theory, but right now you couldn't get a lot of info about it out of him. He works in audio and so has very little need for it -- just needs to know stuff like "use 110 ohm cable for AES/EBU," and the like...

I'm pretty sure those are wrong. They are not impedance transformers but "matching pads." That sounds like the same thing but it's not. What these do, if I'm not mistaken, is add resistance to change a load impedance -- that is, if you've got a 75 ohm source and you want to drive a 50 ohm...

Sorry I couldn't be more encouraging. At 100 feet plus, I would predict huge problems with signal integrity here. The only way out would be impedance transformers--if you do a little bit of Googling you'll find that there are 50/75 ohm units available, but I haven't dug down to see what the...

I don't have an engineering degree, no. But this wire/cable stuff is actually strange -- very few EEs really seem to know much about transmission line theory. I do work with the engineers on this stuff and while the higher math of it tends to escape me we are able to discuss things on pretty...

You don't want to use that. It's a 50 ohm coax, which (together with the fact that it's RG-8, which is huge) is why the center conductor is so big compared to an RG-59. How long are the runs you've buried? This stuff will definitely cause impedance mismatch issues, but if the runs are very...

As I read the spec, it's actually slotted into both the Vertical and the Horizontal Blanking Intervals, which both can contain what the spec calls "Data Island Periods," during which audio and auxiliary data are transmitted. Figure 5-2 in the 1.4b spec seems to indicate as much, anyhow. The...

I have no experience with USB DACs, nor any particular insight into whether some of them are prone to data recovery problems.

Well, you can only judge a data recovery problem by the result in a specific application, and one of the tricky bits with HDMI is that nobody goes around reporting bit errors in a way that the user can verify and count. At short lengths, barring incompetent manufacture (and I have seen some of...

There is always the possibility of video deterioration being sub-threshold while audio deterioration is not, and that depends upon how the video gets handled by the display (and can depend on things like scaling). But when the data recovery is 100%, yes, all HDMI cables will sound the same.

Well, thanks for being insulting. Actually, Blue Jeans Cable is the only brand in the world to use bonded pairs for high impedance stability and low skew -- that's technology you can measure, and we see it when we look at bonded pair Cat 6 and 6a data pairs as well as in the long certification...

By the way, if anyone who's been watching this thread has been waiting for us to get Cat 6a cables back in stock, we've done that, effective today. We had a bit of a technical issue in production which is now resolved, with the result that our Cat 6a cables are passing by larger margins than...

The lack of a spline on something labeled Cat 6 is pretty strongly suggestive that something's wrong. There's no spec requirement for a spline as such, but most people have found one necessary to meet spec because it controls pair-to-pair spacing much better than a non-splined cable, and pair...

We don't compare the twists when measuring them, but when the cable was manufactured, the twist rates were set relative to one another to minimize crosstalk. And yes, you're right about the twist-rate issue; here's how it works, more or less. Common-mode noise rejection in a twisted pair cable...

Not only that, but all the lines in an Ethernet cable are balanced, too--so even without duplexing, the current is flowing one way in one conductor while flowing the opposite way on the other conductor of the same pair. And, of course, current doesn't "know" which way the information is going...

Yep, that's the Cat7 connector I've seen--it isn't compatible with a conventional RJ-45 jack, but I believe there's a hybrid jack made which can take either that or an RJ-45--if I recall correctly, on the four-pair connector pins 1 and 2 map to one pair, 7 and 8 to another, and 3-4-5-6 are used...

That's pretty doggoned silly. And the Nigel Tufnelism in selling "Cat 7" cable with RJ-45 connectors is a nice twist, too. Cat 7, by the way, is so obscure in actual use right now that Belden doesn't even make any in the US. They've got a European division that makes some, which we could...

I certainly would hope so. My guess, and it's only a guess, would be that since bad cable can lead to service calls, they probably are careful to use good cable stock.

That price for 1872A on eBay is superb. I suspect someone must have had a few boxes left over after a job, because that's ridiculously cheap. 1872A is "Mediatwist," which means reduced skew, at some cost to crosstalk (though whenever we've made cables with it, the performance has been just...

By the way, adk highlander, one of the things we're likely to do in the next couple of months is pick up, and test, bulk cable sold in the hardware stores. I've been given a protocol for testing these on our Fluke DTX-1800, and while we can't measure all of the parameters we'd like to (e.g...

That's definitely a more complicated topic than power cords...but I can give you a few thoughts on it here. First, most of us in the USA have pretty good power, and well-designed power supplies will not have a lot of hiccups on it. Most of the time, hiccups are all we're really worried...