Tracks to nowhere?

[Mike Tomlinson]

Posted in another group:

http://imageshack.us/photo/my-images/22/signalstonowhere.jpg/

what are these tracks for?

--
(\_/)
(='.'=)
(")_(")

 

[Chris Bartram]

On 13/12/2012 13:41, Mike Tomlinson wrote:

Posted in another group:

http://imageshack.us/photo/my-images/22/signalstonowhere.jpg/

what are these tracks for?

I'd guess it's an antenna.

 

[John Williamson]

Chris Bartram wrote:

On 13/12/2012 13:41, Mike Tomlinson wrote:

Posted in another group:

http://imageshack.us/photo/my-images/22/signalstonowhere.jpg/

what are these tracks for?

I'd guess it's an antenna.

+1. It's about the right size for a printed cellphone system (3G)
antenna. Reinforced by the SIM1 and SIM2 letering by it.

--
Tciao for Now!

John.

 

[The Natural Philosopher]

On 13/12/12 13:41, Mike Tomlinson wrote:

Posted in another group:

http://imageshack.us/photo/my-images/22/signalstonowhere.jpg/

what are these tracks for?

they are tuned circuits. open ended transmission lines. Or a bored

draughtsman doodling..


--
Ineptocracy

(in-ep-toc’-ra-cy) – a system of government where the least capable to
lead are elected by the least capable of producing, and where the
members of society least likely to sustain themselves or succeed, are
rewarded with goods and services paid for by the confiscated wealth of a
diminishing number of producers.

 

[The Natural Philosopher]

On 13/12/12 14:02, John Williamson wrote:

Chris Bartram wrote:
On 13/12/2012 13:41, Mike Tomlinson wrote:

Posted in another group:

http://imageshack.us/photo/my-images/22/signalstonowhere.jpg/

what are these tracks for?

I'd guess it's an antenna.

+1. It's about the right size for a printed cellphone system (3G)
antenna. Reinforced by the SIM1 and SIM2 letering by it.

ah. could be that as well as a tuned circuit.

--
Ineptocracy

(in-ep-toc’-ra-cy) – a system of government where the least capable to
lead are elected by the least capable of producing, and where the
members of society least likely to sustain themselves or succeed, are
rewarded with goods and services paid for by the confiscated wealth of a
diminishing number of producers.

 

[Brian Gaff]

Maybe they used to make very big wedding cakes there and when they wanted to
move them...
There is a song about it
Tracks of my Tiers.

OK I'll go to sleep again now.

Brian

--
From the Sofa of Brian Gaff Reply address is active
"Chris Bartram" <news@delete-me.piglet-net.net> wrote in message
news:kacmr1$t3a$1@dont-email.me...

On 13/12/2012 13:41, Mike Tomlinson wrote:

Posted in another group:

http://imageshack.us/photo/my-images/22/signalstonowhere.jpg/

what are these tracks for?

I'd guess it's an antenna.

 

[Geo]

On Thu, 13 Dec 2012 13:41:44 +0000, Mike Tomlinson
<mike@jasper.org.uk> wrote:

Posted in another group:

http://imageshack.us/photo/my-images/22/signalstonowhere.jpg/

what are these tracks for?

Replied in another group (diy)

It is a pcb "test coupon" - used them loads of times either on the pcb
or just outside the board edge so that the stack can be tested before
breaking out the board.
Explanation and expoded diagram here:-
http://www.polarinstruments.com/support/cits/AP124.html

 

[Doug White]

Geo <nhhu-o3hu@dea.spamcon.org> wrote in
newssslc8lce073e2q98fiubtelvsvbcc1vjh@4ax.com:

http://www.polarinstruments.com/support/cits/AP124.html

Highly unlikely in this case. Transmission line test structures are
through lines, not open ended stubs. I think it's an antenna of some sort.

Doug White

 

[Dave Platt]

Highly unlikely in this case. Transmission line test structures are
through lines, not open ended stubs. I think it's an antenna of some sort.

As an antenna I don't think it would radiate very well at all. It
appears to have a ground/signal/ground transmission-line structure,
and its serpentine shape would tend to inhibit effective radiation.

In RF applications, open-ended and shorted-ended stubs like this are
often used as impedance-matching elements. At a single frequency and
in the steady state they "look like" high-Q inductors or capacitors,
in series or shunt across the signal. If the PCB's electrical
characteristics are well controlled, it's easier to get a very
reproducible amount of reactance from a stub of this sort, than it is
using a lumped-value component.

--
Dave Platt <dplatt@radagast.org> AE6EO
Friends of Jade Warrior home page: http://www.radagast.org/jade-warrior
I do _not_ wish to receive unsolicited commercial email, and I will
boycott any company which has the gall to send me such ads!

 

On Friday, December 14, 2012 5:37:50 AM UTC-7, Doug White wrote:

Geo <nhhu-o3hu@dea.spamcon.org> wrote in newssslc8lce073e2q98fiubtelvsvbcc1vjh@4ax.com:

http://www.polarinstruments.com/support/cits/AP124.html

Highly unlikely in this case. Transmission line test structures
are through lines, not open ended stubs. I think it's an antenna
of some sort. Doug White

I'm the person who posted the picture, and I should have mentioned
that it's a PC motherboard, MSI brand, model Z68A-G43(G3). It has
no wireless built into it.

I once found an antenna inside a Panasonic-made CRT monitor,
around the flyback. It was 1-2 pieces of circuit board material,
each about 3" long and 1/2" wide. In the schematic, it was
connected to a flyback winding that went nowhere else. Apparently
the antenna put out a signal to counteract interference generated
by the flyback.
transformer.

 

[Gareth Magennis]

"Mike Tomlinson" <mike@jasper.org.uk> wrote in message
news:Cp24t7DYsdyQFw5M@jasper.org.uk...

Posted in another group:

http://imageshack.us/photo/my-images/22/signalstonowhere.jpg/

what are these tracks for?

--
(\_/)
(='.'=)
(")_(")

Long shot, but maybe a simple delay line, like you used to get in old colour
TV's?


Gareth

 

[Arfa Daily]

"Gareth Magennis" <sound.service@btconnect.com> wrote in message
news:xDYys.690133$nB6.224855@fx21.am4...

"Mike Tomlinson" <mike@jasper.org.uk> wrote in message
news:Cp24t7DYsdyQFw5M@jasper.org.uk...

Posted in another group:

http://imageshack.us/photo/my-images/22/signalstonowhere.jpg/

what are these tracks for?

--
(\_/)
(='.'=)
(")_(")



Long shot, but maybe a simple delay line, like you used to get in old
colour
TV's?


Gareth

Don't reckon you'd get much delay down a length of track like that, would
you ? And it seems to be open circuit at the end, anyway. The PAL delay
lines were a glass block with two transducers (lead zirconate titinate ??)
bonded to a pair of faces at a precision-cut angle. Early ones were a large
block with a single out / reflected path. Later ones were much smaller, and
the signal bounced around several times before exiting. Total delay, about
64uS or one UK line period. Luminance delay lines to compensate for the
difference in bandwidth and hence signal transmission speed between the
luminance and chrominance amplifiers, were only a few tens on nS I seem to
recall, and were made from very fine wire wound on a hollow glass rod. Could
those tracks that we're looking at on the photo be any kind of RFID receiver
or responder antennas for automatic inventory or production line process
control purposes ?

Arfa

 

[Doug White]

larrymoencurly@my-deja.com wrote in
news:51e0f44e-2e2b-4526-94a9-9a4d898d111c@googlegroups.com:

On Friday, December 14, 2012 5:37:50 AM UTC-7, Doug White wrote:

Geo <nhhu-o3hu@dea.spamcon.org> wrote in
newssslc8lce073e2q98fiubtelvsvbcc1vjh@4ax.com:

http://www.polarinstruments.com/support/cits/AP124.html

Highly unlikely in this case. Transmission line test structures
are through lines, not open ended stubs. I think it's an antenna
of some sort. Doug White

I'm the person who posted the picture, and I should have mentioned
that it's a PC motherboard, MSI brand, model Z68A-G43(G3). It has
no wireless built into it.

I once found an antenna inside a Panasonic-made CRT monitor,
around the flyback. It was 1-2 pieces of circuit board material,
each about 3" long and 1/2" wide. In the schematic, it was
connected to a flyback winding that went nowhere else. Apparently
the antenna put out a signal to counteract interference generated
by the flyback.
transformer.

It may also be a resonant line for an oscillator or a filter. An open
stub like that can be used to make a resonator for filtering or act as
the "tank" for an oscillator. I've used open stubs like that to kill
unwanted spurs in systems. It will look like a short circuit at the
quarter wave frequency.

Also, just because it doens't have wireless doesn't mean the board wasn't
laid out with that option.

Doug White

 

[Andy Champ]

On 15/12/2012 13:59, Arfa Daily wrote:

Don't reckon you'd get much delay down a length of track like that,
would you ?

I've seen delay lines on tracks - funny zigzag patterns - but these were
in logic analysers, and were designed to keep the tracks from all the
probes the same length.

Andy

 

[Mike Tomlinson]

En el artículo <E_2dnR6H3_krf1HNnZ2dnUVZ8v-dnZ2d@eclipse.net.uk>, Andy
Champ <no.way@nospam.invalid> escribió:

I've seen delay lines on tracks - funny zigzag patterns - but these were
in logic analysers, and were designed to keep the tracks from all the
probes the same length.

Yes, I've seen similar things on PC motherboards, where it's important
to keep the tracks between the CPU/memory controller and the memory
slots the same length.

That isn't what the OP photo shows, though. I certainly agree with
those that think it's an antenna of some kind. Figuring out what "SIM1
and "SIM2" mean might be a clue.

--
(\_/)
(='.'=)
(")_(")

 

[tony sayer]

In article <TGyX1LGt6RzQFwxL@jasper.org.uk>, Mike Tomlinson
<mike@jasper.org.uk> scribeth thus

En el artículo <E_2dnR6H3_krf1HNnZ2dnUVZ8v-dnZ2d@eclipse.net.uk>, Andy
Champ <no.way@nospam.invalid> escribió:

I've seen delay lines on tracks - funny zigzag patterns - but these were
in logic analysers, and were designed to keep the tracks from all the
probes the same length.

Yes, I've seen similar things on PC motherboards, where it's important
to keep the tracks between the CPU/memory controller and the memory
slots the same length.

That isn't what the OP photo shows, though. I certainly agree with
those that think it's an antenna of some kind. Figuring out what "SIM1
and "SIM2" mean might be a clue.

Well is the just simply a PC motherboard?.

If so then very unlikely thats a anything to do with SIM cards, it
prolly means something completely different;!.

It might be that the designer thought it looked nice, and it broke up a
bit of the board that had no copper tracks on...
--
Tony Sayer

 

[polygonum]

On 16/12/2012 10:16, tony sayer wrote:

In article <TGyX1LGt6RzQFwxL@jasper.org.uk>, Mike Tomlinson
mike@jasper.org.uk> scribeth thus
En el artículo <E_2dnR6H3_krf1HNnZ2dnUVZ8v-dnZ2d@eclipse.net.uk>, Andy
Champ <no.way@nospam.invalid> escribió:

I've seen delay lines on tracks - funny zigzag patterns - but these were
in logic analysers, and were designed to keep the tracks from all the
probes the same length.

Yes, I've seen similar things on PC motherboards, where it's important
to keep the tracks between the CPU/memory controller and the memory
slots the same length.

That isn't what the OP photo shows, though. I certainly agree with
those that think it's an antenna of some kind. Figuring out what "SIM1
and "SIM2" mean might be a clue.


Well is the just simply a PC motherboard?.

If so then very unlikely thats a anything to do with SIM cards, it
prolly means something completely different;!.

It might be that the designer thought it looked nice, and it broke up a
bit of the board that had no copper tracks on...

MSI Z68A-G43(G3) desktop motherboard

http://www.techiehq.net/pc-hardware/copper-traces-nowhere-msi-motherboard-87549.html

--
Rod

 

[dennis@home]

On 16/12/2012 10:16, tony sayer wrote:

If so then very unlikely thats a anything to do with SIM cards, it
prolly means something completely different;!.

It might be that the designer thought it looked nice, and it broke up a
bit of the board that had no copper tracks on...

We did some boards where the vias were no bigger than the tracks so a
track that apparently ended actually went through.
It doesn't look like that here though as the other vias are quite big.

 

[Gareth Magennis]

"Mike Tomlinson" <mike@jasper.org.uk> wrote in message
news:TGyX1LGt6RzQFwxL@jasper.org.uk...

En el artículo <E_2dnR6H3_krf1HNnZ2dnUVZ8v-dnZ2d@eclipse.net.uk>, Andy
Champ <no.way@nospam.invalid> escribió:

I've seen delay lines on tracks - funny zigzag patterns - but these were
in logic analysers, and were designed to keep the tracks from all the
probes the same length.

Yes, I've seen similar things on PC motherboards, where it's important
to keep the tracks between the CPU/memory controller and the memory
slots the same length.

That isn't what the OP photo shows, though. I certainly agree with
those that think it's an antenna of some kind. Figuring out what "SIM1
and "SIM2" mean might be a clue.

--
(\_/)
(='.'=)
(")_(")

If its a multilayer board, there might be unseen tracks or planes between
the top and bottom wiggly traces, connected to the other 3 contact points.


Gareth.

 

[Robert Macy]

On Dec 13, 6:41 am, Mike Tomlinson <m...@jasper.org.uk> wrote:

Posted in another group:

http://imageshack.us/photo/my-images/22/signalstonowhere.jpg/

what are these tracks for?

--
 (\_/)
(='.'=)
(")_(")

After downloading your image, copying, and overlaying it seems that
the two patterns do NOT lie on top each other, rather form small
loops. *IF* there is a gnd plane between, doesn't matter if they
overlay or not. They do appear to be the same length of run and do
appear to have a 'guard trace' along each side. But either the vias
are super tiny which doesn't appear to be the case since vias can be
seen in adjacent areas, or those guard traces are floating.

The two sets of pads, SIM1 and SIM2, look like either simply
mechanical access points. If you took an instrument like a network
analyzer with small pointy tips, it looks possible to touch SIM1 &
SIM2 from either side; which would allow you to measure the
transmission line characteristics of both the outside layer processes
and check/control the PCB manufacturing. That's my vote. Although
we've always laid the test traces nearer to the outside, unused areas
of the PCB and therefore the traces were straight.

Just as a note, the vias in that adjacent area look VERY close
together which would cause the power/GND planes to have large holes
cut into them rather than a series of small holes. -- Usually
considered not good for signal integrity AND especially EMC issues.

Did anybody find out what that chip, ASMEDIA ASM1083 does?