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Specifications:
● Conductors: Belden 1694A Solid-Core
Copper
● Dielectric: Polyethylene Foam
● Dual-Layered Foil and Tinned Copper
Braid
● Connectors: Canare RCA (BNC also
Available)
● MSRP: $69 USA for 26 Feet (8 Meters)
Set as Reviewed
Blue Jeans Cable
www.bluejeanscable.com |
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Introduction
Shopping on the Internet is a wonderful experience,
mostly because you can get just about anything out there.
Many companies, whose products are mostly sold by
dealers, offer at least one or two models from their lines on various
websites.
Hi-Fi cables are no exception, and a number of companies
have sprung up, not only offering all of their products for sale on-line,
but for sale only on-line.
This is a tremendous thing for consumers because the
products are less expensive through a direct sale from the manufacturer to
us.
Blue Jeans
Blue Jeans Cable is one of these companies. I saw them
discussed quite a bit in our forum, so I decided to get some for evaluation.
After communicating with Blue Jeans' Sales Department, I
decided on a set of their component video cables. There are several choices
here, and the product for review was a set that consisted of three Belden
1694A solid core conductor cables, grouped together, which is their product
number 7710A when they are ordered with a wrap that holds them together (in
other words, you would order one 7710A which consists of three 1694A cables
with a wrap). My particular set came without any surrounding wrap
(so the order would be for three 1694A cables), and that gave me more flexibility in
running the cables in tighter spaces (it is also less expensive). In fact, I spread them out
side-by-side under the rug, which produced a much smaller hump than would
have been the case if they were held together in a bundle by the wrap, so
you should consider this when ordering them.
The connectors are Canare, which is a very solid plug,
much more so than typical connectors. Also, I believe that the plug and jack
are more responsible for electrical performance than we have given them
credit for in the past, so solid plugs are very important to me. In spite of
such high quality construction, the set is still rather inexpensive,
especially as the length increases (our projector is across the room from
the equipment rack, so we need long video cables).
What Blue Jeans Says
Following is part of a conversation I had with Kurt Denke, from
Blue Jeans Cable, about the Belden 1694A conductors:
This was really our first leading product when we
entered the home theater cable market; we (my wife Pam and I) were becoming
interested in video cabling and I had something of an electronics
background, being a ham radio operator since the 1970s, so I was familiar
with transmission line theory, which is sort of "what it's all about"
video-cable-wise. We were attracted to the Belden 1694A cable because it's
the leading product of Belden's relatively new series of what it calls
"precision video cables."
These cables (the principal series of which include 1505A and 1855A, and the
gigantic 7731A) were developed to serve the professional video industry, in
the face of the rise of SDI (Serial Digital Video) as the dominant standard
for HD production and editing. SDI signals have enormous bandwidth, and, for
reasons which are probably more boring than instructive, that means that
cables carrying SDI over distance need to have particularly tight impedance
tolerance - which is to say, since no video cable can be manufactured always
and exactly to 75 ohm impedance, the "margin of error" within which the
impedance of the manufactured cable may vary. The specified impedance
tolerance of 1694A is +/- 1.5 ohms, but in practice, the product rarely
wanders more than about 1/2 ohm off of the 75 ohm standard.
The importance of consistent and accurate impedance increases dramatically
with distance, so with so many people running cable across theater rooms,
distributing signals around their homes, and the like, the need for a
product like this, cut and configured for home installation, grew. At very
short distances, impedance doesn't matter much; but what is a "short"
distance keeps getting more restrictive, because HD component signals have
quite a bit more bandwidth than standard definition signals, and the higher
the frequencies involved, the shorter the wavelength of the signal, and the
shorter the wavelength, the shorter a cable needs to be for impedance not to
be a factor. At 35 MHz, and with a cable at 83% velocity like 1694A, one
reaches a quarter-wavelength, at 35 MHz, at about six feet.
What we've found, in talking to people about cable quality, is that
impedance consistency is something that doesn't get talked about much, but
it's the most important attribute of an HD video cable. Not much signal is
lost to resistance in a video cable of reasonable length, but quite a bit of
signal quality can be lost to cable being out-of-impedance. With a bad
impedance mismatch, a portion of the signal will reflect back and forth in
the cable rather than being delivered to the display on time; this can
result in ghosting or ringing, and the longer the cable, the more prominent
the effect. Exotic materials and construction techniques have no particular
bearing on this; the only thing that'll control impedance well is to have
very tight manufacturing tolerances, because impedance depends on physical
dimensions: how thick is the center conductor? Does its thickness change
from point to point, and how much? How thick, and how consistent, is the
dielectric? ...and so on.
Traditionally, the best way to control impedance tightly was to use a solid
polyethylene dielectric; older analog video cables like Belden 8281
represent that approach. But there are some problems associated with solid
PE. First, solid PE is rather thick and heavy. 8281, though an RG-59 type
cable, is larger than a modern RG-6, and much stiffer. Second, because solid
PE isn't a very good dielectric as compared to air, one can't make the
center conductor, even in a rather big cable, very large. Third, solid
PE cables invariably wind up with higher capacitance than comparable foam PE
cables.
What Belden did in this generation of video cables was to work hard on the
problem of dielectric foaming. Most modern video cables use a foam
polyethylene dielectric, but foam PE has disadvantages of its own. In
general, it offers much poorer crush resistance than solid PE, and because
it's hard to make bubbles perfectly consistent in size and distribute them
with perfect evenness throughout the dielectric, it's harder to control
impedance. Belden's HDPE (high-density polyethylene) foam, used in 1694A,
resolves those problems with a highly consistent bubble size and
distribution, and because the bubbles also have high physical integrity,
excellent crush resistance. Consequently, Belden can build this cable with
the advantages of a solid PE cable -tight impedance tolerance and high crush
resistance - while also carrying the advantages of a foam dielectric - light
weight, high flexibility, and lower dielectric constant (allowing a larger
center conductor for a given cable size).
The shielding on the 1694A is also top-notch; with a 95% coverage copper
braid and a double-sided, overlapped foil, the shield effectiveness of 1694A
exceeds that of a quad-shield cable at all frequencies. There's an article
about this on our site at:
http://www.bluejeanscable.com/articles/shielding.htm.
This cable has now become the top-selling SDI video cable - it's widely used
in professional installations where long runs of high-bandwidth signals are
required. In fact, its principal competition comes not from other
manufacturers, but from other cables in the same family like 1505A and
1855A, both of which are significantly smaller; as you can imagine, if
you're running a hundred cables in a tray, size starts to become an enormous
consideration, and the manufacturing consistency of the Belden product is so
good that the miniature versions perform just as well as the large versions,
in SDI applications, unless particularly long runs are involved.
Our whole approach in selling cable has been to turn to the professional
market, where specs are tighter than in consumer-market product, and where
pricing is very competitive, and try to identify products which would
translate well to the home environment. 1694A is just a great cable; it's
usable in a variety of applications, and it's economical as well.
As for the connectors - you're probably amply familiar with the Canare
plugs, as there are quite a few people using them. One thing I do try to
mention to people is that, contrary to some of what's been written about the
Canare plugs, there really is no such thing as a true 75 ohm RCA plug; it's
impossible to do because the physical dimensions of the RCA connector don't
allow it. However, the Canare design is really quite impressive in making
the RCA as compatible with a 75 ohm impedance line as possible, by carrying
the departure from 75 ohms as close to the end of the plug as can be.
There's another article on our site on that subject:
http://www.bluejeanscable.com/articles/75ohmrca.htm.
In Use
I tested the Blue Jeans cables with a Denon DVD-5900
player,
Kaleidescape Media Server, and Sony 10-HT digital projector.
First, the Canare plugs are very nice, as they hold the
connection tightly. I have had some trouble in the past with video cables
coming loose from RCA video jacks, and this did not occur here. A loose
connection can result in strange video artifacts (ghost images). An
impedance issue is probably the culprit here.
The cables are rather stiff, but that is because of the
solid core conductor. I prefer this construction though, as I have
experienced connectors breaking off from stranded core cables which are less
sturdy at the solder joint. Of course, I treat cables a little rougher than
a typical consumer who will leave them alone once they are in place, but
this does speak to the overall durability of the two different designs.
Video quality with the player and Kaleidescape server was
excellent. I switched the cables back and forth between sources, with some
tugging on the junctions at the projector, and the connections always
remained tight and solid.
There did not seem to be any video noise induced by the long
cables.
On the Bench
LCR measurement results were as follows:
Capacitance was lower than most of the other cables we
have tested, at 17 pico-Farads/foot, while Inductance was about in the
middle, at 0.11 micro-Henries/Foot. Resistance measured 9.7 milli-Ohms/Foot.
Here is the table for all cable test results.
So, the bench test results are very good.
I was also impressed by the fact that I requested 8 meter
length, and they measured exactly that length. I have ordered long cables in
the past that have been off by as much as a foot or more. I like a company
that pays attention to all the details.
Lastly, read Kurt Denke's comments about his products. It
is very obvious he knows what he is doing, and that inspires consumer
confidence.
Conclusions
The Blue Jeans Cable Component Video set appears to be above
average both in terms of build quality and LCR test results. They are
competitively priced (in fact, lower priced than many), and I have no reservations in recommending them
highly.
- John E. Johnson, Jr. -
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