P
Peter Ceresole
Guest
Woody <usenet@alienrat.co.uk> wrote:
--
Peter
Surely just people who do the funnest hobbies?
--
Peter
P
Peter Ceresole
Guest
Chris Ridd <chrisridd@mac.com> wrote:
--
Peter
You mean Hobbes used an iPod Touch?
--
Peter
E
Eric Jacobsen
Guest
On Sat, 05 Feb 2005 11:56:58 GMT, Robert Baer
<robertbaer@earthlink.net> wrote:
for this sort of thing about twenty years ago for airborne data
gathering. However, those tape drives were big, expensive things that
required custom interfaces, etc., etc. If you have the time to build
some interfaces and dig some of these up (and your airplane is big
enough to carry it (80lbs or so?)), and you can mount it safely, etc.,
it might be a good way to go....
IIRC the IRIG recorders (which we used to use as well) used a specific
standardized format to capture things like time code, position, etc.,
and had limited bandwidth capability. My faulty memory seems to
recall that we put the IRIG data multiplexed in with the captured data
on the high-density tape.
I'm not even sure that those old Ampex HD tape drives could keep up,
though. I seem to remember that the one we used had a max input
clock rate of 10-20MHz and could take 20 tracks or so of data at that
rate. Those numbers are only rough ballpark, it's been a long
time...
I do think that you have a difficult problem, though. Even with the
modern stuff data collection like this can easily challenge the
capabilities of state-of-the-art systems.
Eric Jacobsen
Minister of Algorithms, Intel Corp.
My opinions may not be Intel's opinions.
http://www.ericjacobsen.org
<robertbaer@earthlink.net> wrote:
I almost posted previously about high-density digital tape recorders
for this sort of thing about twenty years ago for airborne data
gathering. However, those tape drives were big, expensive things that
required custom interfaces, etc., etc. If you have the time to build
some interfaces and dig some of these up (and your airplane is big
enough to carry it (80lbs or so?)), and you can mount it safely, etc.,
it might be a good way to go....
IIRC the IRIG recorders (which we used to use as well) used a specific
standardized format to capture things like time code, position, etc.,
and had limited bandwidth capability. My faulty memory seems to
recall that we put the IRIG data multiplexed in with the captured data
on the high-density tape.
I'm not even sure that those old Ampex HD tape drives could keep up,
though. I seem to remember that the one we used had a max input
clock rate of 10-20MHz and could take 20 tracks or so of data at that
rate. Those numbers are only rough ballpark, it's been a long
time...
I do think that you have a difficult problem, though. Even with the
modern stuff data collection like this can easily challenge the
capabilities of state-of-the-art systems.
Eric Jacobsen
Minister of Algorithms, Intel Corp.
My opinions may not be Intel's opinions.
http://www.ericjacobsen.org
Guest
Thanks VERY much for all the informative posts. Please keep em' coming
if you have other info; I'm very grateful.
I'm old enough to remember the big multi-channel analog recorders, but
not quite old enough to have ever used one... Will do more digging
on IRIG, Enertec, Ampex, etc..., as well as the Linux/RAID
configurations, and post what I find.
To answer some of the other questions:
Yes, recording analog close to the antenna gives me the easiest way to
replay a scenario, provided the tape stability and dynamic range are
sufficient. 8 antennas would only require recording 8 channels, but if
I have to record IF instead of RF, it's 24 channels, because we're
actually pulling 3 different signal bands out of each antenna.
Simulation is not feasible *yet*. I need real data from some really
busy airspace first (hundreds of planes, with their tcas and
transponder systems squittering away) in order to get realistic
statistics (signal levels, overlaps/collisions, etc...) Then I can
create all kinds of models with controlled deviations from a known,
realistic environment. But the "real world" sanity check is essential.
Analog recording is preferred, to capture the effects of ultra-close
transmitters saturating my receiver.
Aircraft will either be a slow jet or a small turboprop, depending on
which is available. No high-rate maneuvers. I don't know what to expect
in terms of microphonic effects from aircraft vibration, but as long as
it's realistic (on the antennas, not on my recorder!), I'll be glad to
have it. (Ideal scenario would be jet *and* turboprop data thru same
airspace at same time, to see any differences.)
Not yet sure how I would interface my A/D converters to a fast disk
array, but since I have an FPGA deserializing and processing the A/D
input, some compression inside the FPGA (simple deltas?) is an obvious
option that I didn't think of; thanks for pointing it out!!!
Regarding the 90GB/min disk arrays: I didn't know you could get 'em
that fast! (Any recommended suppliers?) 12 channels at 90MB/sec = 64.8
GB/minute; at that rate I could put about 16 minutes of uncompressed
data on a 1TB drive. That would certainly get me out of the starting
gate.
Thanks again, very, very much!
mj
if you have other info; I'm very grateful.
I'm old enough to remember the big multi-channel analog recorders, but
not quite old enough to have ever used one...
Will do more diggingon IRIG, Enertec, Ampex, etc..., as well as the Linux/RAID
configurations, and post what I find.
To answer some of the other questions:
Yes, recording analog close to the antenna gives me the easiest way to
replay a scenario, provided the tape stability and dynamic range are
sufficient. 8 antennas would only require recording 8 channels, but if
I have to record IF instead of RF, it's 24 channels, because we're
actually pulling 3 different signal bands out of each antenna.
Simulation is not feasible *yet*. I need real data from some really
busy airspace first (hundreds of planes, with their tcas and
transponder systems squittering away) in order to get realistic
statistics (signal levels, overlaps/collisions, etc...) Then I can
create all kinds of models with controlled deviations from a known,
realistic environment. But the "real world" sanity check is essential.
Analog recording is preferred, to capture the effects of ultra-close
transmitters saturating my receiver.
Aircraft will either be a slow jet or a small turboprop, depending on
which is available. No high-rate maneuvers. I don't know what to expect
in terms of microphonic effects from aircraft vibration, but as long as
it's realistic (on the antennas, not on my recorder!), I'll be glad to
have it. (Ideal scenario would be jet *and* turboprop data thru same
airspace at same time, to see any differences.)
Not yet sure how I would interface my A/D converters to a fast disk
array, but since I have an FPGA deserializing and processing the A/D
input, some compression inside the FPGA (simple deltas?) is an obvious
option that I didn't think of; thanks for pointing it out!!!
Regarding the 90GB/min disk arrays: I didn't know you could get 'em
that fast! (Any recommended suppliers?) 12 channels at 90MB/sec = 64.8
GB/minute; at that rate I could put about 16 minutes of uncompressed
data on a 1TB drive. That would certainly get me out of the starting
gate.
Thanks again, very, very much!
mj
T
Tim Williams
Guest
"Robert Baer" <robertbaer@earthlink.net> wrote in message
news:Odk8f.2916$yX2.2374@newsread2.news.pas.earthlink.net...
could ever work.
My understanding is the transistor has an additive (OR) choice between base
current and light turning on the collector.
Tim
--
Deep Fryer: a very philosophical monk.
Website: http://webpages.charter.net/dawill/tmoranwms
news:Odk8f.2916$yX2.2374@newsread2.news.pas.earthlink.net...
No?? If it's NPN, it's going to be forward-biased! I don't see how that
could ever work.
My understanding is the transistor has an additive (OR) choice between base
current and light turning on the collector.
Tim
--
Deep Fryer: a very philosophical monk.
Website: http://webpages.charter.net/dawill/tmoranwms
T
Too_Many_Tools
Guest
I would have to agree....and so why I asked the original question to
see if I was missing something offered in the marketplace.
I guess one just needs to wait for the manufacturers to offer the
product for a market segment they have yet to address.
TMT
see if I was missing something offered in the marketplace.
I guess one just needs to wait for the manufacturers to offer the
product for a market segment they have yet to address.
TMT
E
ehsjr
Guest
Watson A.Name - "Watt Sun, the Dark Remover" wrote:
for output voltage of 25 volts or less, and shows the circuit
without that protection.
Ed
It's not needed. The datasheet says no protection diode is needed
for output voltage of 25 volts or less, and shows the circuit
without that protection.
Ed
T
Tim Williams
Guest
"Robert Baer" <robertbaer@earthlink.net> wrote in message
news:_yE8f.1180$8c5.717@newsread3.news.pas.earthlink.net...
useful switching character of a transistor.
Tim
--
Deep Fryer: a very philosophical monk.
Website: http://webpages.charter.net/dawill/tmoranwms
news:_yE8f.1180$8c5.717@newsread3.news.pas.earthlink.net...
Ok, so you get a variable knee (i.e., variable Vbe) diode? Kinda spoils the
useful switching character of a transistor.
Tim
--
Deep Fryer: a very philosophical monk.
Website: http://webpages.charter.net/dawill/tmoranwms
T
Too_Many_Tools
Guest
I would agree....would you want your cell phone to come with a cord
that you had to plug into a stationary socket before using it?
HDTV will not be a replacement for NTSC until it does everything that
NTSC does now...everything.
And the public will not accept it until it does everything that it
replaces.
NTSC will be with us longer than anyone wants to admit.
TMT
that you had to plug into a stationary socket before using it?
HDTV will not be a replacement for NTSC until it does everything that
NTSC does now...everything.
And the public will not accept it until it does everything that it
replaces.
NTSC will be with us longer than anyone wants to admit.
TMT
A
Andy Cuffe
Guest
On Sat, 29 Oct 2005 08:01:33 GMT, James Sweet <jamessweet@hotmail.com>
wrote:
what caused it, but it was something minor.
Andy Cuffe
baltimora@psu.edu <-- Use this address until 12/31/2005
acuffe@gmail.com <-- Use this address after 12/31/2005
wrote:
I repaired a HV shutdown problem with the one I had. I can't remember
what caused it, but it was something minor.
Andy Cuffe
baltimora@psu.edu <-- Use this address until 12/31/2005
acuffe@gmail.com <-- Use this address after 12/31/2005
B
Brenda Ann
Guest
"Too_Many_Tools" <too_many_tools@yahoo.com> wrote in message
news:1130599716.679710.274170@g14g2000cwa.googlegroups.com...
I know I won't be buying an HDTV receiver any time soon, they're still WAY
out of my budget. I can buy a 27" NTSC set that looks just fine for what's
being broadcast for $175, it's 10x to 12x that for the cheapest HDTV ready
(without the HDTV tuner) set. Damn if I'll pay more than a week's wages for
a TV set, there's just nothing worth that kind of scratch to WATCH on them.
news:1130599716.679710.274170@g14g2000cwa.googlegroups.com...
I'd like to believe that, but I'm afraid that the FCC has other ideas.
I know I won't be buying an HDTV receiver any time soon, they're still WAY
out of my budget. I can buy a 27" NTSC set that looks just fine for what's
being broadcast for $175, it's 10x to 12x that for the cheapest HDTV ready
(without the HDTV tuner) set. Damn if I'll pay more than a week's wages for
a TV set, there's just nothing worth that kind of scratch to WATCH on them.
M
Mat Nieuwenhoven
Guest
On Tue, 21 Feb 2006 10:06:21 -0500, Ol' Duffer wrote:
http://www.helmut-singer.de/fix/she.html
E.g. the Philips PM3320A for digital (10 bit, 4k deep), or the PM3295/40 for
analog. PM3... numbers appear to be scopes with Philips.
Mat Nieuwenhoven
If you don't mind buying second hand, look at:
http://www.helmut-singer.de/fix/she.html
E.g. the Philips PM3320A for digital (10 bit, 4k deep), or the PM3295/40 for
analog. PM3... numbers appear to be scopes with Philips.
Mat Nieuwenhoven
D
David C. Partridge
Guest
I'd suggest a second hand Tek 7000 series. I bought a 7904 (500MHz) with
plugins not long back, and after fixing the PSU, its a great scope. I paid
GBP 180 plus about 30 in parts to fix. Probes of course need to be bought
as well ...
A 78x4 is also a great scope with a BW of > 400MHz, in fact the 7854 will
typically give a 7904 a serious run for its money, but make sure you get one
with the keyboard and the right plugins. The storage versions (e.g. 7834)
can be cranky and hard to fix I am told.
If you want portable, then for about USD 700 or so you can get a 2465B or
2467B.
Dave
plugins not long back, and after fixing the PSU, its a great scope. I paid
GBP 180 plus about 30 in parts to fix. Probes of course need to be bought
as well ...
A 78x4 is also a great scope with a BW of > 400MHz, in fact the 7854 will
typically give a 7904 a serious run for its money, but make sure you get one
with the keyboard and the right plugins. The storage versions (e.g. 7834)
can be cranky and hard to fix I am told.
If you want portable, then for about USD 700 or so you can get a 2465B or
2467B.
Dave
Y
Yukio YANO
Guest
Zak wrote:
2nd choice would a Sandwich of Copper-Foil Tape and sheet of plastic.
two sources come to mind, 1. Adhesive coated Copper Tape used to Alarm
Windows.
2. Copper Tape, from Hobby stores for
"Stained Glass" projects.
I used the Double sided PC board about 40 years ago while working for a
Bio-medical Telemetry Equipment company.
Yukio YANO
First choice would be a scrap of double-sided Printed-Circuit Board !
2nd choice would a Sandwich of Copper-Foil Tape and sheet of plastic.
two sources come to mind, 1. Adhesive coated Copper Tape used to Alarm
Windows.
2. Copper Tape, from Hobby stores for
"Stained Glass" projects.
I used the Double sided PC board about 40 years ago while working for a
Bio-medical Telemetry Equipment company.
Yukio YANO
K
KC
Guest
I think Hameg still makes good scopes with CRT for a fair price. Analog
and Digital in one scope.
If you want to buy second hand watch-out with Philips scopes.
Performance and quality is very good but the PM3xxx is very difficult
to repair. Philips used a lot of potted sub-modules and there are no
spare parts. Fluke took over the Philips measurement and killed the
high-end
The PM3320A is not a Philips I think. Its Philips out-side and Hameg
in-side
KC
and Digital in one scope.
If you want to buy second hand watch-out with Philips scopes.
Performance and quality is very good but the PM3xxx is very difficult
to repair. Philips used a lot of potted sub-modules and there are no
spare parts. Fluke took over the Philips measurement and killed the
high-end
The PM3320A is not a Philips I think. Its Philips out-side and Hameg
in-side
KC
J
JeffM
Guest
yyq787@gmail.com MULTI-POSTED:
http://groups.google.com/group/sci.electronics.cad/browse_frm/thread/4c71337116e88ad3/fcc9bb5dd90e61a4?q=zz-zz+instead-of-being-posted-to-the-group+too-lazy
http://groups.google.com/groups/search?filter=0&enc_author=exJrVBAAAAB14RCcCsW_O86ZzPip1uMb
DO NOT MULTI-POST:
******DO NOT FAIL TO READ THIS******
http://groups.google.com/group/sci.electronics.basics/browse_frm/thread/7b7c0624331012bb/3958f18673b5f374?q=EVERY-group-*-*-*-*-*-*-*-*-appear+*-proper-answer-*-*-*-given+much-easier-*-*-*-*-what's-going-on+*-frowned-on+*-correcting+*-polite-*-mention-*-*-*-*-*-*-*+Just-because-*-*-*-*-*-*-*-*-does-not-mean-*-*-*-*-*-*+*-Followup-To-*+*-*-*-too-lazy-*-*-*-*-*-appropriate-*+*-*-_perfect_-*-*-*-*+*-*-*-*-two-groups-*-*-aren't-*-different
...
...
To all: The answer is here:
http://groups.google.com/group/comp.lsi.testing/browse_frm/thread/255f7cb03da4a697/96b83dda96091589?q=zzz+Virginia-Tech-CAD-tools-group
You really DON'T "get" Usenet.
http://groups.google.com/group/sci.electronics.cad/browse_frm/thread/4c71337116e88ad3/fcc9bb5dd90e61a4?q=zz-zz+instead-of-being-posted-to-the-group+too-lazy
http://groups.google.com/groups/search?filter=0&enc_author=exJrVBAAAAB14RCcCsW_O86ZzPip1uMb
DO NOT MULTI-POST:
******DO NOT FAIL TO READ THIS******
http://groups.google.com/group/sci.electronics.basics/browse_frm/thread/7b7c0624331012bb/3958f18673b5f374?q=EVERY-group-*-*-*-*-*-*-*-*-appear+*-proper-answer-*-*-*-given+much-easier-*-*-*-*-what's-going-on+*-frowned-on+*-correcting+*-polite-*-mention-*-*-*-*-*-*-*+Just-because-*-*-*-*-*-*-*-*-does-not-mean-*-*-*-*-*-*+*-Followup-To-*+*-*-*-too-lazy-*-*-*-*-*-appropriate-*+*-*-_perfect_-*-*-*-*+*-*-*-*-two-groups-*-*-aren't-*-different
...
...
To all: The answer is here:
http://groups.google.com/group/comp.lsi.testing/browse_frm/thread/255f7cb03da4a697/96b83dda96091589?q=zzz+Virginia-Tech-CAD-tools-group
B
Brad Velander
Guest
No,
You really dont' get it! Nobody elected you to police Usenet and direct
everyone as to how to use it. The next troll will complain that these people
are cross-posting. Go find something better to do with your time, your
efforts are wasted.
If you have something on topic to post then by all means post, otherwise
your messages are more of a nuisance then those you are complaining about.
Afterall at least their messages are usually on topic and unless people
monitor all those other groups one would never even know they are
multiposting.
--
Sincerely,
Brad Velander.
"JeffM" <jeffm_@email.com> wrote in message
news:1141589153.372356.198210@i39g2000cwa.googlegroups.com...
You really dont' get it! Nobody elected you to police Usenet and direct
everyone as to how to use it. The next troll will complain that these people
are cross-posting. Go find something better to do with your time, your
efforts are wasted.
If you have something on topic to post then by all means post, otherwise
your messages are more of a nuisance then those you are complaining about.
Afterall at least their messages are usually on topic and unless people
monitor all those other groups one would never even know they are
multiposting.
--
Sincerely,
Brad Velander.
"JeffM" <jeffm_@email.com> wrote in message
news:1141589153.372356.198210@i39g2000cwa.googlegroups.com...
J
JeffM
Guest
They are based on logic. Abide by them or expect to be called on it.
You need to follow the link and read it as well.
http://groups.google.com/group/sci.electronics.cad/browse_frm/thread/4c71337116e88ad3/fcc9bb5dd90e61a4?q=zz-zz+instead-of-being-posted-to-the-group+too-lazy
...
...
Apologists for idiots are even worse than the idiots.
I
Ian Bell
Guest
Brad Velander wrote:
Ian
You should take your own advice.
Ian
N
Noah Little
Guest
Brad Velander wrote to JeffM:
abrasive, the links he posted should be required reading for everyone
before they're allowed on Usenet.
Now if we could just get people to realize that sometimes multi-posting
is appropriate, and failure to trim replies is even worse than top
posting.
--
Noah
Nor did they you. While JeffM's style may have been unnecessarily
abrasive, the links he posted should be required reading for everyone
before they're allowed on Usenet.
Now if we could just get people to realize that sometimes multi-posting
is appropriate, and failure to trim replies is even worse than top
posting.
--
Noah