J
Jeroen Belleman
Guest
On 2012-10-29 10:33, Fred Abse wrote:
Jeroen Belleman
Do you have any idea where one can buy resistive cable?
Jeroen Belleman
T
TheGlimmerMan
Guest
On Mon, 29 Oct 2012 11:35:46 +0100, Jeroen Belleman
<jeroen@nospam.please> wrote:
R per foot value. Meant to be an emission suppressive passage for HV
pulses being fed to the plugs, something which generally causes a pretty
big magnetic spike to emanate.
There were folks in the '50s and '60s (hams) who even went so far as to
fully ground shield each of their spark plug wires to reduce the problem.
Then they (those 'they' people) came out with the better, resistive wire
and the problem sufficiently subsided..
May not be exactly what you seek, but that is the only version I am
aware of.
<jeroen@nospam.please> wrote:
Modern automotive "spark plug wire". Has a "graphite core". Specific
R per foot value. Meant to be an emission suppressive passage for HV
pulses being fed to the plugs, something which generally causes a pretty
big magnetic spike to emanate.
There were folks in the '50s and '60s (hams) who even went so far as to
fully ground shield each of their spark plug wires to reduce the problem.
Then they (those 'they' people) came out with the better, resistive wire
and the problem sufficiently subsided..
May not be exactly what you seek, but that is the only version I am
aware of.
S
Spehro Pefhany
Guest
On Mon, 29 Oct 2012 11:35:46 +0100, Jeroen Belleman
<jeroen@nospam.please> wrote:
Probably easiest to buy a scope probe and cut the ends off!
See: Patent number: 2883619
Issue date: Apr 21, 1959
<jeroen@nospam.please> wrote:
Probably easiest to buy a scope probe and cut the ends off!
See: Patent number: 2883619
Issue date: Apr 21, 1959
J
Jamie
Guest
TheGlimmerMan wrote:
in the heating and ventilation system. THe problem, no blower operation.
After tearing out the blower box under the glove compartment, which
was a big job getting to, I found there was nothing wrong with the
blower motor. The plug was too hard to get to so it wasn't an easy
option to simply test it before hand. So I went to the control switch,
that worked ok. So I then started ripping apart the harness, they had
put a resistor wire in the harness for the blower to reduce the brush
noise in the electrical system.
At that point, I really didn't care much for the car, it was getting
old, so I just hung a copper wire outside of the harness.. I can say
this, not only was that wire there to reduce noise, it also served as a
voltage drop to the blower, that thing was like a wind tunnel afterwards
Jamie
We had an old car here once that I decided to tackle a blower problem
in the heating and ventilation system. THe problem, no blower operation.
After tearing out the blower box under the glove compartment, which
was a big job getting to, I found there was nothing wrong with the
blower motor. The plug was too hard to get to so it wasn't an easy
option to simply test it before hand. So I went to the control switch,
that worked ok. So I then started ripping apart the harness, they had
put a resistor wire in the harness for the blower to reduce the brush
noise in the electrical system.
At that point, I really didn't care much for the car, it was getting
old, so I just hung a copper wire outside of the harness.. I can say
this, not only was that wire there to reduce noise, it also served as a
voltage drop to the blower, that thing was like a wind tunnel afterwards
Jamie
J
Jamie
Guest
Jeroen Belleman wrote:
http://www.awcwire.com/ProductSpec.aspx?id=RG178B-Coaxial-Cable
Jamie
http://www.awcwire.com/ProductSpec.aspx?id=RG178B-Coaxial-Cable
Jamie
J
John Larkin
Guest
On Sat, 20 Oct 2012 12:42:11 -0800, Robert Baer
<robertbaer@localnet.com> wrote:
This is my best birthday present.
https://dl.dropbox.com/u/53724080/Truckee/Birthday_Baer.jpg
grrrrrrrr.
<robertbaer@localnet.com> wrote:
This is my best birthday present.
https://dl.dropbox.com/u/53724080/Truckee/Birthday_Baer.jpg
grrrrrrrr.
J
Jamie
Guest
John Larkin wrote:
Jamie
Jamie
F
Fred Abse
Guest
On Mon, 29 Oct 2012 11:35:46 +0100, Jeroen Belleman wrote:
order. That implies a few thousand feet to get a cable manufacturer
interested.
*Almost* the same effect can be got by putting a small (tens to hundreds
of ohms) in series with each end, if all you want is to damp resonances in
a probe.
You might try a few of the "usual suspect" cable manufacturers. There are
a few specialist cable companies in Germany who claim to make small
quantities of specials to order.
--
"For a successful technology, reality must take precedence
over public relations, for nature cannot be fooled."
(Richard Feynman)
I suspect that probe manufacturers get their resistive cables made to
order. That implies a few thousand feet to get a cable manufacturer
interested.
*Almost* the same effect can be got by putting a small (tens to hundreds
of ohms) in series with each end, if all you want is to damp resonances in
a probe.
You might try a few of the "usual suspect" cable manufacturers. There are
a few specialist cable companies in Germany who claim to make small
quantities of specials to order.
--
"For a successful technology, reality must take precedence
over public relations, for nature cannot be fooled."
(Richard Feynman)
J
Jeroen
Guest
On 2012-10-29 22:16, Fred Abse wrote:
to see if they could deliver any. They said they were willing to make
it to my specs, provided I'd buy at least 1km. I'd need a dozen or so
five-meter pieces. Oh well. Maybe Spehro was right: Just chop of the
unwanted ends off a scope probe.
Jeroen Belleman
It's the scope probe type cable I'm after indeed. I contacted Draka
to see if they could deliver any. They said they were willing to make
it to my specs, provided I'd buy at least 1km. I'd need a dozen or so
five-meter pieces. Oh well. Maybe Spehro was right: Just chop of the
unwanted ends off a scope probe.
I tried that. Not good enough.
Thanks, I'll shop around.
Jeroen Belleman
J
John Larkin
Guest
On Mon, 29 Oct 2012 15:06:46 -0500, Jamie
<jamie_ka1lpa_not_valid_after_ka1lpa_@charter.net> wrote:
trees are mostly farmed, a renewable resource.
The cabin is sort of a small-scale ripoff of a Frank Lloyd Wright
church in Madison, Wisconsin. Go see it if you're even in the
neighborhood. The church, I mean.
http://www.bc.edu/bc_org/avp/cas/fnart/fa267/flw/unitarian01.jpg
The baer was done by an elementary school kid, part of a fund raiser
up in Truckee. My other birthday present was the snow.
--
John Larkin Highland Technology Inc
www.highlandtechnology.com jlarkin at highlandtechnology dot com
Precision electronic instrumentation
Picosecond-resolution Digital Delay and Pulse generators
Custom timing and laser controllers
Photonics and fiberoptic TTL data links
VME analog, thermocouple, LVDT, synchro, tachometer
Multichannel arbitrary waveform generators
<jamie_ka1lpa_not_valid_after_ka1lpa_@charter.net> wrote:
Don't know. The entire cabin is knotty pine, inside and out. But pine
trees are mostly farmed, a renewable resource.
The cabin is sort of a small-scale ripoff of a Frank Lloyd Wright
church in Madison, Wisconsin. Go see it if you're even in the
neighborhood. The church, I mean.
http://www.bc.edu/bc_org/avp/cas/fnart/fa267/flw/unitarian01.jpg
The baer was done by an elementary school kid, part of a fund raiser
up in Truckee. My other birthday present was the snow.
--
John Larkin Highland Technology Inc
www.highlandtechnology.com jlarkin at highlandtechnology dot com
Precision electronic instrumentation
Picosecond-resolution Digital Delay and Pulse generators
Custom timing and laser controllers
Photonics and fiberoptic TTL data links
VME analog, thermocouple, LVDT, synchro, tachometer
Multichannel arbitrary waveform generators
R
Robert Baer
Guest
Robert Baer wrote:
Dimensions:
+++ +++
| |++++++++++++++++++++++++++| |
----| |----
| |++++++++++++++++++++++++++| |
+++ +++
^-------metal end caps-------^
Metal end caps 0.285 dia, body 0.265 dia, end cap width 0.180, and
end-to-end width 2.085 inches
Most plastics (for insulation and support of the floating shield)
have roughly 3 for dielectric constant, and a tube minimum diameter
would contact only the end caps at best; 1/16 wall thickness at smallest.
on a resistor; VERY hard to implement.
Dimensions:
+++ +++
| |++++++++++++++++++++++++++| |
----| |----
| |++++++++++++++++++++++++++| |
+++ +++
^-------metal end caps-------^
Metal end caps 0.285 dia, body 0.265 dia, end cap width 0.180, and
end-to-end width 2.085 inches
Most plastics (for insulation and support of the floating shield)
have roughly 3 for dielectric constant, and a tube minimum diameter
would contact only the end caps at best; 1/16 wall thickness at smallest.
R
Robert Baer
Guest
Fred Abse wrote:
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.
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.
R
Robert Baer
Guest
Fred Abse wrote:
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).
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).
R
Robert Baer
Guest
Jeroen Belleman wrote:
to rat out the cable from a P6015..
Unless one is VERY fortunate to find it in a surplus house or willing
to rat out the cable from a P6015..
R
Robert Baer
Guest
TheGlimmerMan wrote:
resistance to radio frequency interference. NGK wires have a lower
resistance than conventional carbon core wires (8k ohm/meter vs. 16k
ohm/meter)."
So these "better" spark plug wires have a "mere" 2.4K/foot
resistance, which exceeds a desirable amount by about an order of magnitude.
Excellent suggestion, however..
construction method known as "variable pitch" wire winding to create
resistance to radio frequency interference. NGK wires have a lower
resistance than conventional carbon core wires (8k ohm/meter vs. 16k
ohm/meter)."
So these "better" spark plug wires have a "mere" 2.4K/foot
resistance, which exceeds a desirable amount by about an order of magnitude.
Excellent suggestion, however..
R
Robert Baer
Guest
Spehro Pefhany wrote:
R
Robert Baer
Guest
Jamie wrote:
R
Robert Baer
Guest
Fred Abse wrote:
R
Robert Baer
Guest
Jamie wrote:
for the RG179 which is 75 ohms but otherwise rather similar.
Spice listing (Belden 83265 is RG-178B/U 50 ohms) .. but data used was
for the RG179 which is 75 ohms but otherwise rather similar.
S
Sjouke Burry
Guest
Robert Baer <robertbaer@localnet.com> wrote in
news:_SGjs.67$Ns4.41@newsfe09.iad:
Any car repair shop.
Used to hook up spark plugs.
news:_SGjs.67$Ns4.41@newsfe09.iad:
Any car repair shop.
Used to hook up spark plugs.