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Tektronix P6019 AC Current Probe Termination - DIY?

  • Thread starter Klaus Vestergaard Kragelund
  • Start date
K

Klaus Vestergaard Kragelund

Jan 1, 1970
0
Hi

I've got at Tektronix P6019 AC Current probe (presumeable 10Hz to 40MHz) at
Ebay.com pretty cheap. I do not have the '134 probe amplifier, but I have
been testing it and it seems to work ok with 50 ohms termination at the
scope input directly.

Anyone know of the correct termination or perhaps what compensation is
needed. It does not give the correct signal below approx. 1kHz

Or perhaps someone has a manual they are willing to scan and mail?

Thanks

Klaus
 
M

mike

Jan 1, 1970
0
Klaus said:
Hi

I've got at Tektronix P6019 AC Current probe (presumeable 10Hz to 40MHz)

Why would you presume 10 Hz?
I don't have a catalog old enough to list it, but 10 Hz. seems way too low.

It's basically an inductor. Measure the inductance. The time constant
is L/R. So the lower the resistance, the better the low frequency
response. Run it into a virtual ground like they do in the active
probes. You still have to do some tweaking on the high frequency end
where the parasitics take over.
As I recall, the 6019 had a switched box that sacrificed 5x gain
to get down to 170 Hz. or thereabouts. The P6021 Box sez
10mA/mV lf -3dB 120 Hz. 2mA/mV is 450 Hz.

mike

--
Return address is VALID.
Bunch of stuff For Sale and Wanted at the link below.
Toshiba & Compaq LiIon Batteries, Test Equipment
Honda CB-125S $800 in PDX
TEK Sampling Sweep Plugin and RM564
Tek 2465 $800, ham radio, 30pS pulser
Tektronix Concept Books, spot welding head...
http://www.geocities.com/SiliconValley/Monitor/4710/
 
J

Jim Yanik

Jan 1, 1970
0
Hi

I've got at Tektronix P6019 AC Current probe (presumeable 10Hz to
40MHz) at Ebay.com pretty cheap. I do not have the '134 probe
amplifier, but I have been testing it and it seems to work ok with 50
ohms termination at the scope input directly.

Anyone know of the correct termination or perhaps what compensation is
needed. It does not give the correct signal below approx. 1kHz

Or perhaps someone has a manual they are willing to scan and mail?

Thanks

Klaus

I may be remembering wrong,but ISTR a L-pad used for calibrating the
current probe separate from the 134 amplifier,it used a 62 ohm seies R with
a terminating 50 ohm R,to the scope BNC.It would still limit BW,IIRC.
But that pad may be for the P6021/22 probes,sorry for my poor memory.


Probably the only ones with manuals for these current probes will be the US
military or cal labs,and perhaps TEK microfiche.Trying to get the right
part numbers for the manual will be difficult.You might try calling the DC
TEK field office,and try to talk to a tech.
 
J

James Meyer

Jan 1, 1970
0
Hi

I've got at Tektronix P6019 AC Current probe (presumeable 10Hz to 40MHz) at
Ebay.com pretty cheap. I do not have the '134 probe amplifier, but I have
been testing it and it seems to work ok with 50 ohms termination at the
scope input directly.

Anyone know of the correct termination or perhaps what compensation is
needed. It does not give the correct signal below approx. 1kHz

Or perhaps someone has a manual they are willing to scan and mail?

Thanks

Klaus

I'm pretty sure there's one at work. I'll be at home for the rest of
the week. I'll look for the paperwork when I get back. The manual is quite
thick with lots of information. I'll start with the schematic of the probe and
the input amplifier.

Fell flat of my back on an unexpected bit of "black ice" a week ago and
have been laid up at home with a broken rib and a sprained arm. Usually I would
welcome an excuse not to go in to work, but this time I think I over did it.
Next time someone finds me lying in the parking lot looking up at the sky, I
hope they just shoot me to put me out of my misery.

Jim
 
W

Winfield Hill

Jan 1, 1970
0
James Meyer wrote...
Fell flat of my back on an unexpected bit of "black ice" a week ago
and have been laid up at home with a broken rib and a sprained arm.

Hmm, bones not as strong as they used to be? I fear for many of us
it's time to start with the daily calcium pills.

Thanks,
- Win

whill_at_picovolt-dot-com
 
M

Michael A. Terrell

Jan 1, 1970
0
James said:
I'm pretty sure there's one at work. I'll be at home for the rest of
the week. I'll look for the paperwork when I get back. The manual is quite
thick with lots of information. I'll start with the schematic of the probe and
the input amplifier.

Fell flat of my back on an unexpected bit of "black ice" a week ago and
have been laid up at home with a broken rib and a sprained arm. Usually I would
welcome an excuse not to go in to work, but this time I think I over did it.
Next time someone finds me lying in the parking lot looking up at the sky, I
hope they just shoot me to put me out of my misery.

Jim

I have an idea how you feel, I fell down a flight of stairs once,
when i was in my 20s. I didn't see that the landing at the top was wet,
and I went down, hitting every step, till I was laying in the basement
for over a half hour before I could move again. Another time i was on a
roof when a strong gust of wind literally blew me off the roof There was
a set of tracks going up, and none coming down. I hit the top of the
ladder and it fell. I landed on my back, on the ladder and ruined it. By
the grace of God, I stood up and walked away with no pain or damage that
time. Get well, and be more careful. ;-)
--
1 day!


Michael A. Terrell
Central Florida
 
K

Klaus Vestergaard Kragelund

Jan 1, 1970
0
mike said:
Why would you presume 10 Hz?

I presume 10Hz due to the statements I have found on Google about this
probe....
I don't have a catalog old enough to list it, but 10 Hz. seems way too low.

It's basically an inductor. Measure the inductance. The time constant
is L/R. So the lower the resistance, the better the low frequency
response. Run it into a virtual ground like they do in the active
probes. You still have to do some tweaking on the high frequency end
where the parasitics take over.

I did a lot of searching on Google and didn't succeed in finding a circuit
for an active probe. By running it into the virtual ground is that done to
use a current driven amplifier?

Thanks

Klaus
 
K

Klaus Vestergaard Kragelund

Jan 1, 1970
0
James Meyer said:
I'm pretty sure there's one at work. I'll be at home for the rest of
the week. I'll look for the paperwork when I get back. The manual is quite
thick with lots of information. I'll start with the schematic of the probe and
the input amplifier.

That would simply be great - much better than any gift I'm going to receive
tonight :)
Fell flat of my back on an unexpected bit of "black ice" a week ago and
have been laid up at home with a broken rib and a sprained arm. Usually I would
welcome an excuse not to go in to work, but this time I think I over did it.
Next time someone finds me lying in the parking lot looking up at the sky, I
hope they just shoot me to put me out of my misery.

Jim, sorry for your accident - hope you have a speedy recovery....

Cheers

Klaus
 
J

James Meyer

Jan 1, 1970
0
James Meyer wrote...

Hmm, bones not as strong as they used to be? I fear for many of us
it's time to start with the daily calcium pills.

Thanks,
- Win

whill_at_picovolt-dot-com

I've been taking supplimental calcium for three or four years now.
Maybe that made the difference between only one fractured rib and a sprained arm
as contrasted to several broken ribs and a fractured pelvis.

Any way, I continue to feel better day by day and just as soon as I can
contort my body enough to slip into my car, I'm heading back to work.

Jim
 
J

James Meyer

Jan 1, 1970
0
I have an idea how you feel, I fell down a flight of stairs once,
when i was in my 20s. I didn't see that the landing at the top was wet,
and I went down, hitting every step, till I was laying in the basement
for over a half hour before I could move again. Another time i was on a
roof when a strong gust of wind literally blew me off the roof There was
a set of tracks going up, and none coming down. I hit the top of the
ladder and it fell. I landed on my back, on the ladder and ruined it. By
the grace of God, I stood up and walked away with no pain or damage that
time.

Ouch! It was a small patch of ice that got me. We had some freezing
rain one morning. I waited until the sun came up to get started. Watching the
news reports let me plan my route into work to avoid the major pile-ups on the
road. Had absolutely no problems on the trip. My little Subaru with 4WD is
very sure footed. Parked at work and checked the pavement where I parked for
ice and found it only wet. Was feeling very good about making it that far with
no problems. As I started across the parking lot to the back entrance I had to
pass a spot in the shade of a big bush and the next thing I know, I'm looking
straight up in the air.

Get well, and be more careful. ;-)

I'm sure that I'll pay a lot more attention to *that* spot in the
future. Only thing is, next time I'll probably be concentrating at watching
where my feet are going and get run over by a UPS delivery truck coming up on my
blind side. :cool:

Jim
 
M

mike

Jan 1, 1970
0
Klaus said:
I presume 10Hz due to the statements I have found on Google about this
probe....

The spec for a 6021 with the amplifier is ~12 Hz. That's probably
where the number came from. That's about the best you can hope
for with an active probe, virtual ground, current input.
Can't get there with the passive box.

Keep your eyes out for a P6042. Goes all the way to DC.
mike
I did a lot of searching on Google and didn't succeed in finding a circuit
for an active probe. By running it into the virtual ground is that done to
use a current driven amplifier?

Thanks

Klaus



--
Return address is VALID.
Bunch of stuff For Sale and Wanted at the link below.
Toshiba & Compaq LiIon Batteries, Test Equipment
Honda CB-125S $800 in PDX
TEK Sampling Sweep Plugin and RM564
Tek 2465 $800, ham radio, 30pS pulser
Tektronix Concept Books, spot welding head...
http://www.geocities.com/SiliconValley/Monitor/4710/
 
K

Klaus Vestergaard Kragelund

Jan 1, 1970
0
mike said:
The spec for a 6021 with the amplifier is ~12 Hz. That's probably
where the number came from. That's about the best you can hope
for with an active probe, virtual ground, current input.
Can't get there with the passive box.

Ok - will be interesting to see how I can do with a simple setup of an P6019
and DIY termination
Keep your eyes out for a P6042. Goes all the way to DC.
mike

Yes. I started out looking for a A622 (DC to 100 kHz), but that came up too
pricey for my wallet on ebay (200$). Perhaps next year..... Anyway measuring
HF currents means more to me than knowing the absolute DC value :)

Cheers

Klaus
 
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