M
Michael A. Terrell
Guest
krw@att.bizzz wrote:
Are you fir real?
Are you fir real?
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J
josephkk
Guest
On Tue, 30 Oct 2012 07:28:06 -0700, John Larkin
<jjlarkin@highNOTlandTHIStechnologyPART.com> wrote:
the Way grows. And surely proper behavior to parents and elder brothers is
the trunk of goodness.' (Ancient Chinese. Analects, i. 2)
<jjlarkin@highNOTlandTHIStechnologyPART.com> wrote:
'It is upon the trunk that a gentleman works. When that is firmly set up,On Tue, 30 Oct 2012 07:37:17 -0500, amdx <amdx@knologynotthis.net
wrote:
On 10/30/2012 6:56 AM, John Fields wrote:
On Tue, 30 Oct 2012 04:16:12 -0700, John Larkin
jjlarkin@highNOTlandTHIStechnologyPART.com> wrote:
On Tue, 30 Oct 2012 00:40:38 -0400, "Michael A. Terrell"
mike.terrell@earthlink.net> wrote:
Robert Baer wrote:
Jamie wrote:
John Larkin wrote:
On Sat, 20 Oct 2012 12:42:11 -0800, Robert Baer
robertbaer@localnet.com> wrote:
See similar title in a.b.s.electronic for PDF.
Almost took longer to document than to build..
This is my best birthday present.
https://dl.dropbox.com/u/53724080/Truckee/Birthday_Baer.jpg
grrrrrrrr.
how many pine trees had to be cut down to build that wall for you?
Jamie
If you were a true tree huger, you _would_ "pine" for them..
He's just another sap...
It's not nice to needle people like that.
---
Still barking, I see.
Root around long enough, and we'll find a pun.
Mikek
That stems from our basic need for humor.
the Way grows. And surely proper behavior to parents and elder brothers is
the trunk of goodness.' (Ancient Chinese. Analects, i. 2)
R
Robert Baer
Guest
Robert Baer wrote:
Fred Abse wrote:
On Sun, 28 Oct 2012 19:11:03 -0800, Robert Baer wrote:
** This is what i have, before i saw your response; not too bad
considering simple compensation and implicit coax of indeterminate (but
limited) length to scope end.
You can't ignore the effect of what is, in effect, an open-circuit
quarter
wave line, at a frequency within the intended bandwidth of the probe.
3 feet of 0,66 velocity coax, terminated in a large resistance will
resonate at about 54MHz, and ring like a bell. That's why resistive
cables
are used.
Perhaps, but us mortals with a limited budget cannot order umpteen
thousand feet of coax with a resistive center.
The P6015 used ten feet of coax with resistive center (direct quote from
manual).
Cannot say what its resistance is..i read 657 ohms end-to-end on the
cable, and the schematic states 150 ohms 10% at probe end, implying the
coax center is about 500 ohms (~5 ohms per foot).
Since you specified 75 ohm cable, the R should then be 75 ohms instead
of 60 ohms (pickie).
Sorry...mistype... cable is about 50 ohms per foot.
R
Robert Baer
Guest
Sjouke Burry wrote:
Robert Baer<robertbaer@localnet.com> wrote in
news:_SGjs.67$Ns4.41@newsfe09.iad:
Jeroen Belleman wrote:
On 2012-10-29 10:33, Fred Abse wrote:
On Sun, 28 Oct 2012 19:11:03 -0800, Robert Baer wrote:
** This is what i have, before i saw your response; not too bad
considering simple compensation and implicit coax of indeterminate
(but limited) length to scope end.
You can't ignore the effect of what is, in effect, an open-circuit
quarter
wave line, at a frequency within the intended bandwidth of the
probe.
3 feet of 0,66 velocity coax, terminated in a large resistance will
resonate at about 54MHz, and ring like a bell. That's why resistive
cables
are used.
Do you have any idea where one can buy resistive cable?
CUT
Any car repair shop.
Used to hook up spark plugs.
Resistance is about an order of magnitude higher than desired.
R
Robert Baer
Guest
Michael A. Terrell wrote:
Robert Baer wrote:
Jamie wrote:
John Larkin wrote:
On Sat, 20 Oct 2012 12:42:11 -0800, Robert Baer
robertbaer@localnet.com> wrote:
See similar title in a.b.s.electronic for PDF.
Almost took longer to document than to build..
This is my best birthday present.
https://dl.dropbox.com/u/53724080/Truckee/Birthday_Baer.jpg
grrrrrrrr.
how many pine trees had to be cut down to build that wall for you?
Jamie
If you were a true tree huger, you _would_ "pine" for them..
He's just another sap...
OOooo!
R
Robert Baer
Guest
Jan Panteltje wrote:
much larger diameter nichrome wire, and i do not know where one can buy
"plain" resistive wire like that.
Suggestions?
Oh, "insert" might be a bitch..one might be forced to spot-weld the
resistive wire to the existing internal wire.
And it ain't easy to pull out....
BUT where does that resistance wire come from? Most heaters have aOn a sunny day (Mon, 29 Oct 2012 18:21:22 -0800) it happened Robert Baer
robertbaer@localnet.com> wrote in<%QGjs.66$Ns4.53@newsfe09.iad>:
Perhaps, but us mortals with a limited budget cannot order umpteen
thousand feet of coax with a resistive center.
The P6015 used ten feet of coax with resistive center (direct quote
from manual).
Cannot say what its resistance is..i read 657 ohms end-to-end on the
cable, and the schematic states 150 ohms 10% at probe end, implying the
coax center is about 500 ohms (~5 ohms per foot).
Personally for a one case, I would take normal coax,
pull the center conductor out,
and insert thinner resistance wire.
Should work for length of 1m or there about.
Not sure if that helps for your case.
That sounds like it may be do-able.
much larger diameter nichrome wire, and i do not know where one can buy
"plain" resistive wire like that.
Suggestions?
Oh, "insert" might be a bitch..one might be forced to spot-weld the
resistive wire to the existing internal wire.
And it ain't easy to pull out....
R
Robert Baer
Guest
Sum Ting Wong wrote:
that the insulation is hot-cast onto the wire..On Tue, 30 Oct 2012 08:29:45 GMT, Jan Panteltje
pNaonStpealmtje@yahoo.com> wrote:
On a sunny day (Mon, 29 Oct 2012 18:21:22 -0800) it happened Robert Baer
robertbaer@localnet.com> wrote in<%QGjs.66$Ns4.53@newsfe09.iad>:
Perhaps, but us mortals with a limited budget cannot order umpteen
thousand feet of coax with a resistive center.
The P6015 used ten feet of coax with resistive center (direct quote
from manual).
Cannot say what its resistance is..i read 657 ohms end-to-end on the
cable, and the schematic states 150 ohms 10% at probe end, implying the
coax center is about 500 ohms (~5 ohms per foot).
Personally for a one case, I would take normal coax,
pull the center conductor out,
and insert thinner resistance wire.
Should work for length of 1m or there about.
Not sure if that helps for your case.
Yeah, like dragging the center conductor out of a meter long piece of
coax is an easy task, much less feeding another back through.
Standard RG-8 center conductor dielectric strength is 1.5kV.and they
are not easy to get out. Fairly tightly bound to the core media.
Probably cheaper to find and get the right stuff.
Reason why center conductors are virtually impossible to pull out,is
R
Robert Baer
Guest
Fred Abse wrote:
On Mon, 29 Oct 2012 18:07:28 -0800, Robert Baer wrote:
It has been a loooong time; Tektronix made two high voltage probes -
one with a significantly higher voltage rating.
The one i have _did_ have the liquid inside but that has slowly
leaked out over the ages; it is the P6015 rated at 20KV, 40KV peak.
I think that is the top end in voltage.
Not any more. It has derated itself to about 12kV. It won't do 40kV
anymore without the fluorocarbon.
If you can get the 114 from somewhere, you can recharge it. See the manual.
Know where that rainbow is----^ ?
R
Robert Baer
Guest
John Larkin wrote:
On Tue, 30 Oct 2012 00:40:38 -0400, "Michael A. Terrell"
mike.terrell@earthlink.net> wrote:
Robert Baer wrote:
Jamie wrote:
John Larkin wrote:
On Sat, 20 Oct 2012 12:42:11 -0800, Robert Baer
robertbaer@localnet.com> wrote:
See similar title in a.b.s.electronic for PDF.
Almost took longer to document than to build..
This is my best birthday present.
https://dl.dropbox.com/u/53724080/Truckee/Birthday_Baer.jpg
grrrrrrrr.
how many pine trees had to be cut down to build that wall for you?
Jamie
If you were a true tree huger, you _would_ "pine" for them..
He's just another sap...
It's not nice to needle people like that.
Excellent!! You are on a roll!
T
tm
Guest
"Robert Baer" <robertbaer@localnet.com> wrote in message
news:1_1ks.526$TD5.320@newsfe01.iad...
Many scopes have a probe power source available with +/- 15 volts or so.
There is plenty of room in the handle of a 1 Gohm to 10 meg 1000X probe to
put an opamp and other parts.
news:1_1ks.526$TD5.320@newsfe01.iad...
Why not make an active HV probe and have it drive a standard cable?Sum Ting Wong wrote:
On Tue, 30 Oct 2012 08:29:45 GMT, Jan Panteltje
pNaonStpealmtje@yahoo.com> wrote:
On a sunny day (Mon, 29 Oct 2012 18:21:22 -0800) it happened Robert Baer
robertbaer@localnet.com> wrote in<%QGjs.66$Ns4.53@newsfe09.iad>:
Perhaps, but us mortals with a limited budget cannot order umpteen
thousand feet of coax with a resistive center.
The P6015 used ten feet of coax with resistive center (direct quote
from manual).
Cannot say what its resistance is..i read 657 ohms end-to-end on the
cable, and the schematic states 150 ohms 10% at probe end, implying the
coax center is about 500 ohms (~5 ohms per foot).
Personally for a one case, I would take normal coax,
pull the center conductor out,
and insert thinner resistance wire.
Should work for length of 1m or there about.
Not sure if that helps for your case.
Yeah, like dragging the center conductor out of a meter long piece of
coax is an easy task, much less feeding another back through.
Standard RG-8 center conductor dielectric strength is 1.5kV.and they
are not easy to get out. Fairly tightly bound to the core media.
Probably cheaper to find and get the right stuff.
Reason why center conductors are virtually impossible to pull out,is
that the insulation is hot-cast onto the wire..
Many scopes have a probe power source available with +/- 15 volts or so.
There is plenty of room in the handle of a 1 Gohm to 10 meg 1000X probe to
put an opamp and other parts.
S
Sum Ting Wong
Guest
On Tue, 30 Oct 2012 20:41:08 -0800, Robert Baer <robertbaer@localnet.com>
wrote:
plated copper shielding. So tightly it makes a deep fingerprint
impression of the overbraid onto the core media. It doesn't just slide
off either.
wrote:
Then wrapped even tighter by a Chinese handcuff overbraid of silverSum Ting Wong wrote:
Yeah, like dragging the center conductor out of a meter long piece of
coax is an easy task, much less feeding another back through.
Standard RG-8 center conductor dielectric strength is 1.5kV.and they
are not easy to get out. Fairly tightly bound to the core media.
Probably cheaper to find and get the right stuff.
Reason why center conductors are virtually impossible to pull out,is
that the insulation is hot-cast onto the wire..
plated copper shielding. So tightly it makes a deep fingerprint
impression of the overbraid onto the core media. It doesn't just slide
off either.
Guest
On Oct 25, 12:22 am, josephkk <joseph_barr...@sbcglobal.net> wrote:
it." Gen. Robrt. E. Lee, CSA
James Arthur
"It is well that war is so terrible, else we should grow too fond ofOn Wed, 24 Oct 2012 07:13:13 -0700 (PDT), dagmargoodb...@yahoo.com wrote:
Nobody is doing route clearance by picking up IEDs with their bare hands.
Actually, they do. And, they walk the route, in front of their
vehicles. Not always, but as conditions require.
I was similarly appalled. My pal explained that in many places their
Buffaloes (armored vehicles) don't give good enough visibility, often
they can just turn you into a blind target. And, the IEDs are *very*
hard to see. Better to be out where you can see.
They have certain precautions in their favor (which shall go
unposted). But yes, manually, especially to disarm. The Buffalo has
an extensible arm; they use that too where they can.
I asked if he actually found any. "Oh yeah. Constantly. Several,
the hard way."
It changed him. He saw things men should not see.
I must disagree that last one. Some must see, to make sure that the
knowledge (and sometimes the horror) is not lost. Just like some (a few
every few years) must see Dr. Mengele's work. See also Holocaust museums
and the early nuclear museums in Hiroshima and Nagasaki (the nuclear
museums have recently been toned down, wrongly in my view).
it." Gen. Robrt. E. Lee, CSA
James Arthur
J
Jan Panteltje
Guest
On a sunny day (Tue, 30 Oct 2012 20:39:44 -0800) it happened Robert Baer
<robertbaer@localnet.com> wrote in <KY1ks.525$TD5.455@newsfe01.iad>:
several types at several Ohm/meter, some VERY thin.
I have used it to make thermocouples.
I am sure US has many places that sell that wire.
Yes the inner coax does not always come out easy,
I have done it, put one end in the vice, and take an hour to pull it out.
Use gloves, hurt my hands doing it...
<robertbaer@localnet.com> wrote in <KY1ks.525$TD5.455@newsfe01.iad>:
Well I just order it from conrad.nl,Personally for a one case, I would take normal coax,
pull the center conductor out,
and insert thinner resistance wire.
Should work for length of 1m or there about.
Not sure if that helps for your case.
That sounds like it may be do-able.
BUT where does that resistance wire come from? Most heaters have a
much larger diameter nichrome wire, and i do not know where one can buy
"plain" resistive wire like that.
Suggestions?
Oh, "insert" might be a bitch..one might be forced to spot-weld the
resistive wire to the existing internal wire.
And it ain't easy to pull out....
several types at several Ohm/meter, some VERY thin.
I have used it to make thermocouples.
I am sure US has many places that sell that wire.
Yes the inner coax does not always come out easy,
I have done it, put one end in the vice, and take an hour to pull it out.
Use gloves, hurt my hands doing it...
S
Spehro Pefhany
Guest
On Tue, 30 Oct 2012 20:39:44 -0800, the renowned Robert Baer
<robertbaer@localnet.com> wrote:
isn't all that bad. In a pinch, brass or stainless are pretty awful
tempco-wise, but relatively high resistance.
These guys have 25m lengths of it with Kapton insulation:-
http://www.iceoxford.com/Cryogenic-spares/Wiring.htm
If you need many pounds/kg of it, it's easy to buy.
accidentally).. the dielectric is slippery PE, I think, and the center
wire a thick smooth solid wire. But it's awfully stiff for test prod
wire.
Best regards,
Spehro Pefhany
--
"it's the network..." "The Journey is the reward"
speff@interlog.com Info for manufacturers: http://www.trexon.com
Embedded software/hardware/analog Info for designers: http://www.speff.com
<robertbaer@localnet.com> wrote:
It comes on spools- manganin is better than nichrome, but nichromeJan Panteltje wrote:
On a sunny day (Mon, 29 Oct 2012 18:21:22 -0800) it happened Robert Baer
robertbaer@localnet.com> wrote in<%QGjs.66$Ns4.53@newsfe09.iad>:
Perhaps, but us mortals with a limited budget cannot order umpteen
thousand feet of coax with a resistive center.
The P6015 used ten feet of coax with resistive center (direct quote
from manual).
Cannot say what its resistance is..i read 657 ohms end-to-end on the
cable, and the schematic states 150 ohms 10% at probe end, implying the
coax center is about 500 ohms (~5 ohms per foot).
Personally for a one case, I would take normal coax,
pull the center conductor out,
and insert thinner resistance wire.
Should work for length of 1m or there about.
Not sure if that helps for your case.
That sounds like it may be do-able.
BUT where does that resistance wire come from? Most heaters have a
much larger diameter nichrome wire, and i do not know where one can buy
"plain" resistive wire like that.
isn't all that bad. In a pinch, brass or stainless are pretty awful
tempco-wise, but relatively high resistance.
These guys have 25m lengths of it with Kapton insulation:-
http://www.iceoxford.com/Cryogenic-spares/Wiring.htm
If you need many pounds/kg of it, it's easy to buy.
Except for cable TV coax where it seems pretty easy to pull out (espSuggestions?
Oh, "insert" might be a bitch..one might be forced to spot-weld the
resistive wire to the existing internal wire.
And it ain't easy to pull out....
accidentally).. the dielectric is slippery PE, I think, and the center
wire a thick smooth solid wire. But it's awfully stiff for test prod
wire.
Best regards,
Spehro Pefhany
--
"it's the network..." "The Journey is the reward"
speff@interlog.com Info for manufacturers: http://www.trexon.com
Embedded software/hardware/analog Info for designers: http://www.speff.com
J
Jan Panteltje
Guest
On a sunny day (Wed, 31 Oct 2012 04:39:51 -0400) it happened Spehro Pefhany
<speffSNIP@interlogDOTyou.knowwhat> wrote in
<2io198hvid0hv2gjnsbge5va66g8r2l7tu@4ax.com>:
and mine are flexible (those are the ones with the F-type? connectors you just
screw over the folded back screen / outside plastic, inner solid core is the 'pin').
<speffSNIP@interlogDOTyou.knowwhat> wrote in
<2io198hvid0hv2gjnsbge5va66g8r2l7tu@4ax.com>:
The satellite cables (to the LNB) also have single core,Except for cable TV coax where it seems pretty easy to pull out (esp
accidentally).. the dielectric is slippery PE, I think, and the center
wire a thick smooth solid wire. But it's awfully stiff for test prod
wire.
and mine are flexible (those are the ones with the F-type? connectors you just
screw over the folded back screen / outside plastic, inner solid core is the 'pin').
M
Michael A. Terrell
Guest
Robert Baer wrote:
Does Tektronix or HP list the vendor in their parts list? They do
for most parts.
Jan Panteltje wrote:
On a sunny day (Mon, 29 Oct 2012 18:21:22 -0800) it happened Robert Baer
robertbaer@localnet.com> wrote in<%QGjs.66$Ns4.53@newsfe09.iad>:
Perhaps, but us mortals with a limited budget cannot order umpteen
thousand feet of coax with a resistive center.
The P6015 used ten feet of coax with resistive center (direct quote
from manual).
Cannot say what its resistance is..i read 657 ohms end-to-end on the
cable, and the schematic states 150 ohms 10% at probe end, implying the
coax center is about 500 ohms (~5 ohms per foot).
Personally for a one case, I would take normal coax,
pull the center conductor out,
and insert thinner resistance wire.
Should work for length of 1m or there about.
Not sure if that helps for your case.
That sounds like it may be do-able.
BUT where does that resistance wire come from? Most heaters have a
much larger diameter nichrome wire, and i do not know where one can buy
"plain" resistive wire like that.
Suggestions?
Oh, "insert" might be a bitch..one might be forced to spot-weld the
resistive wire to the existing internal wire.
And it ain't easy to pull out....
Does Tektronix or HP list the vendor in their parts list? They do
for most parts.
J
Jeroen Belleman
Guest
On 2012-10-31 15:28, Michael A. Terrell wrote:
itself as manufacturer of most parts, cable included. Interestingly,
it lists the cable as '39 ohm' cable. The resistance of the central
conductor of a 1m P6106 cable is about 130 ohms. The geometry of the
cable suggests a Z0 much higher than 39 ohms, so I don't know what
this is supposed to mean.
Jeroen Belleman
Good suggestiin the P6106 manualon, but no luck. Tektronix listsRobert Baer wrote:
Jan Panteltje wrote:
On a sunny day (Mon, 29 Oct 2012 18:21:22 -0800) it happened Robert Baer
robertbaer@localnet.com> wrote in<%QGjs.66$Ns4.53@newsfe09.iad>:
Perhaps, but us mortals with a limited budget cannot order umpteen
thousand feet of coax with a resistive center.
The P6015 used ten feet of coax with resistive center (direct quote
from manual).
Cannot say what its resistance is..i read 657 ohms end-to-end on the
cable, and the schematic states 150 ohms 10% at probe end, implying the
coax center is about 500 ohms (~5 ohms per foot).
Personally for a one case, I would take normal coax,
pull the center conductor out,
and insert thinner resistance wire.
Should work for length of 1m or there about.
Not sure if that helps for your case.
That sounds like it may be do-able.
BUT where does that resistance wire come from? Most heaters have a
much larger diameter nichrome wire, and i do not know where one can buy
"plain" resistive wire like that.
Suggestions?
Oh, "insert" might be a bitch..one might be forced to spot-weld the
resistive wire to the existing internal wire.
And it ain't easy to pull out....
Does Tektronix or HP list the vendor in their parts list? They do
for most parts.
itself as manufacturer of most parts, cable included. Interestingly,
it lists the cable as '39 ohm' cable. The resistance of the central
conductor of a 1m P6106 cable is about 130 ohms. The geometry of the
cable suggests a Z0 much higher than 39 ohms, so I don't know what
this is supposed to mean.
Jeroen Belleman
M
Michael A. Terrell
Guest
Jeroen Belleman wrote:
How asking someone who makes probes?
http://www.probemaster.com/index.php
Michael A. Terrell wrote:
Does Tektronix or HP list the vendor in their parts list?
They do for most parts.
Good suggestiin the P6106 manualon, but no luck. Tektronix lists
itself as manufacturer of most parts, cable included. Interestingly,
it lists the cable as '39 ohm' cable. The resistance of the central
conductor of a 1m P6106 cable is about 130 ohms. The geometry of the
cable suggests a Z0 much higher than 39 ohms, so I don't know what
this is supposed to mean.
How asking someone who makes probes?
http://www.probemaster.com/index.php
F
Frank Miles
Guest
On Wed, 31 Oct 2012 17:34:32 +0100, Jeroen Belleman wrote:
Hmmn. Maybe 39ohms/ft (series resistance)?On 2012-10-31 15:28, Michael A. Terrell wrote:
Robert Baer wrote:
Jan Panteltje wrote:
On a sunny day (Mon, 29 Oct 2012 18:21:22 -0800) it happened Robert
Baer <robertbaer@localnet.com> wrote
in<%QGjs.66$Ns4.53@newsfe09.iad>:
Perhaps, but us mortals with a limited budget cannot order
umpteen
thousand feet of coax with a resistive center.
The P6015 used ten feet of coax with resistive center (direct
quote
from manual).
Cannot say what its resistance is..i read 657 ohms end-to-end on
the
cable, and the schematic states 150 ohms 10% at probe end, implying
the coax center is about 500 ohms (~5 ohms per foot).
Personally for a one case, I would take normal coax, pull the center
conductor out,
and insert thinner resistance wire.
Should work for length of 1m or there about.
Not sure if that helps for your case.
That sounds like it may be do-able.
BUT where does that resistance wire come from? Most heaters have
a
much larger diameter nichrome wire, and i do not know where one can
buy "plain" resistive wire like that.
Suggestions?
Oh, "insert" might be a bitch..one might be forced to spot-weld
the
resistive wire to the existing internal wire.
And it ain't easy to pull out....
Does Tektronix or HP list the vendor in their parts list? They do
for most parts.
Good suggestiin the P6106 manualon, but no luck. Tektronix lists itself
as manufacturer of most parts, cable included. Interestingly, it lists
the cable as '39 ohm' cable. The resistance of the central conductor of
a 1m P6106 cable is about 130 ohms. The geometry of the cable suggests a
Z0 much higher than 39 ohms, so I don't know what this is supposed to
mean.
Jeroen Belleman
F
Fred Abse
Guest
On Wed, 31 Oct 2012 17:34:32 +0100, Jeroen Belleman wrote:
--
"For a successful technology, reality must take precedence
over public relations, for nature cannot be fooled."
(Richard Feynman)
P6015 manual describes the cable as "50 ohms per foot".Good suggestiin the P6106 manualon, but no luck. Tektronix lists itself as
manufacturer of most parts, cable included. Interestingly, it lists the
cable as '39 ohm' cable. The resistance of the central conductor of a 1m
P6106 cable is about 130 ohms. The geometry of the cable suggests a Z0
much higher than 39 ohms, so I don't know what this is supposed to mean.
--
"For a successful technology, reality must take precedence
over public relations, for nature cannot be fooled."
(Richard Feynman)