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Late last year I purchased a P6022 current probe on ebay, which was advertised as being in good working condition, although on the pictures it was evident that at the very least that probe had seen a lot of use given the wear on the labels. There is also some stiffness in the connecting cable due to aging, but otherwise it still looks good and shows no apparent damage anywhere.
When I tested this probe with the 134 probe amplifier and attempted to compare it to my P6021, results where not very consistent, and at some point I noticed that when I somewhat squeezed the sides of the probe body about half way along the body, the readings would jump up or down. I then opened the probe by following the instructions in the manual, and under the microscope saw that one of the solder joints of the transformer windings was obviously broken. I resoldered that joint and attempted to reassemble the probe with that long spring in place, but at some point the tip started to show some fine stress fractures from the pressure that the spring exerts on it, so I removed the spring and reassembled the probe without it.
Except for not closing itself the probe seems to work fine and the jumping readings while squeezing the probe body are gone. I am sure that had I left the spring in it, the tip of the probe where the sliding part engages into would have broken off as I can clearly see some hairline cracks forming in that area. I looked online but I only found the upper slide part in Greece. However what I need to replace is really the lower portion. Although I am not in any rush to do that, but if the opportunity would present itself I would certainly consider it.
Has anybody done this same thing, removing the spring to relieve the stress to the tip? Or is there perhaps another reason why the spring needs to remain inside the probe as it might affect the calibration? Its a piece of metal quite close to the transformer windings. I was at first considering just shortening the spring a bit to reduce its tension, but in the end decided to completely remove it. The probe now easily slides open and closes, and I guess its just a matter to make sure it is properly closed before taking any readings.
I still have to compare the readings between the 6022 and the 6021 to see if they make sense, with the 134 set to the correct probe model. So that is something that I still need to do. My guess is that I will have to do this at a frequency that would fall inside the operating range of both probes. Any suggestions welcomed. Thanks.
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It's not the spring that stresses the plastic, it's the extra tension when you close the probe fully.? On my P6021, the slot at the end that the slider's tab engages broke.? I epoxied onto the nose a bit of sheet metal with an angle bend for the tab.? That
was maybe ten years?ago and it's holding fine, spring and all.
I own a P6021 (LF 2nd gen) and a P6020 (HF 1st?gen).? I discovered that the 134's LF COMP adjustment had to be quite different for those two.? After cursing the designer for not including two pots, I bought a second 134 so each probe has its own dedicated amplifier.
Dave Wise
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Show quoted text
Late last year I purchased a P6022 current probe on ebay, which was advertised as being in good working condition, although on the pictures it was evident that at the very least that probe had seen a lot of use given the wear on the labels. There is also
some stiffness in the connecting cable due to aging, but otherwise it still looks good and shows no apparent damage anywhere.
When I tested this probe with the 134 probe amplifier and attempted to compare it to my P6021, results where not very consistent, and at some point I noticed that when I somewhat squeezed the sides of the probe body about half way along the body, the readings
would jump up or down. I then opened the probe by following the instructions in the manual, and under the microscope saw that one of the solder joints of the transformer windings was obviously broken. I resoldered that joint and attempted to reassemble the
probe with that long spring in place, but at some point the tip started to show some fine stress fractures from the pressure that the spring exerts on it, so I removed the spring and reassembled the probe without it.
Except for not closing itself the probe seems to work fine and the jumping readings while squeezing the probe body are gone. I am sure that had I left the spring in it, the tip of the probe where the sliding part engages into would have broken off as I can
clearly see some hairline cracks forming in that area. I looked online but I only found the upper slide part in Greece. However what I need to replace is really the lower portion. Although I am not in any rush to do that, but if the opportunity would present
itself I would certainly consider it.
Has anybody done this same thing, removing the spring to relieve the stress to the tip? Or is there perhaps another reason why the spring needs to remain inside the probe as it might affect the calibration? Its a piece of metal quite close to the transformer
windings. I was at first considering just shortening the spring a bit to reduce its tension, but in the end decided to completely remove it. The probe now easily slides open and closes, and I guess its just a matter to make sure it is properly closed before
taking any readings.
I still have to compare the readings between the 6022 and the 6021 to see if they make sense, with the 134 set to the correct probe model. So that is something that I still need to do. My guess is that I will have to do this at a frequency that would fall inside
the operating range of both probes. Any suggestions welcomed. Thanks.
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Alex:
As SMPS/EBU/magneitcs designer and mfg ,since 1970s I Have used TEK current probes and amps , have had many. such probes and problems.
1/ Buying used ff epay is ALWAYS risky: Besides the transformer terms and cables, the main risk is the VERY fragile split ferrite core in the jaws: This ceramic parts is thin crosssection and very brittle.
Dropping the probe head A FEW INCHES on a had surfce can cause hairline cracks in the core half.
2/ Hard to see the defect at first but your note is typical, inconsistent perrformance as the probes is used.
3/ Mechanical is VERY carefully setup so the spring and TINY ball beraing appy a specified pressure at the jaws to mate the mirror polizshed core halvs.
Disassembly, fooling wih the sprin or (worse) loosisng the ball beraing WILL result in bad colsure and inconsistent readings.
4/ Give away is a beatup probe plastic jaw, or dirty or scored mirror ferrite jaw surface: Probe has been mistreated.
5/ Eben repair of the cable let alone the ferrite is very difficult to succeed.
6/ We never use the old 134 amps as we have the correct P6021 and P6022 TERM boxes (often lost when the probe is sild)
7/ Amp 134 DOEs give some benefits and sone prefer it.
8 The DC hall effect probes are very similar in construction and same points apply.
9/ Test is simple:
Take 50 Ohm axial 1/4W resistor, connect with short RG174/U etc with BNC to 50 Ohm pulse generator
Set for 2..10V peak, square wave.
Look at current wave over a wide range of PRF and tie scae.
To see the actual current just place a scope voltage probe across the 50 Ohm r.
Bon Chance
Jon
Thus I = Vpeak/50
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Jon, very useful info, but please translate this
line near to the end:--
Look at current wave over a wide range of PRF and tie scae.
Cheers, Les.
On 2/5/24 19:43, Froggie the Gremlin
wrote:
toggle quoted message
Show quoted text
Alex:
As SMPS/EBU/magneitcs designer and mfg ,since 1970s I Have used TEK current probes and amps , have had many. such probes and problems.
1/ Buying used ff epay is ALWAYS risky: Besides the transformer terms and cables, the main risk is the VERY fragile split ferrite core in the jaws: This ceramic parts is thin crosssection and very brittle.
Dropping the probe head A FEW INCHES on a had surfce can cause hairline cracks in the core half.
2/ Hard to see the defect at first but your note is typical, inconsistent perrformance as the probes is used.
3/ Mechanical is VERY carefully setup so the spring and TINY ball beraing appy a specified pressure at the jaws to mate the mirror polizshed core halvs.
Disassembly, fooling wih the sprin or (worse) loosisng the ball beraing WILL result in bad colsure and inconsistent readings.
4/ Give away is a beatup probe plastic jaw, or dirty or scored mirror ferrite jaw surface: Probe has been mistreated.
5/ Eben repair of the cable let alone the ferrite is very difficult to succeed.
6/ We never use the old 134 amps as we have the correct P6021 and P6022 TERM boxes (often lost when the probe is sild)
7/ Amp 134 DOEs give some benefits and sone prefer it.
8 The DC hall effect probes are very similar in construction and same points apply.
9/ Test is simple:
Take 50 Ohm axial 1/4W resistor, connect with short RG174/U etc with BNC to 50 Ohm pulse generator
Set for 2..10V peak, square wave.
Look at current wave over a wide range of PRF and tie scae.
To see the actual current just place a scope voltage probe across the 50 Ohm r.
Bon Chance
Jon
Thus I = Vpeak/50
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Alex, Leslie: Sorry for the scramble....All thumbs on a mobile...CORRECTION
"Look at current wave over a wide range of PRF (Pulse Repetition Frequency) and Time scale. (eg 1 kHz, 10kHz 100kHz 1 MHz )
To see the actual current just place a scope voltage probe across the 50 Ohm R
SETUP: Pulse Gen >>>50 Ohm R
Place prober under test around resistor body, and place a 1x or 10X probe in parallel with gen out or across resistor.
NOTE: Many TEK scopes have a current CL loop.
and CAL like PG506
Enjoy,
Jon
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I am certain he meant time scale. -Chuck Harris On Mon, 5 Feb 2024 20:35:03 +0000 "Leslie Austin via groups.io" <Manxduke@...> wrote: Jon, very useful info, but please translate this line near to the
end:--
Look at current wave over a wide range of PRF and tie scae.
Cheers, Les.
On 2/5/24 19:43, Froggie the Gremlin wrote:
Alex:
As SMPS/EBU/magneitcs designer and mfg ,since 1970s I Have used
TEK current probes and amps , have had many. such probes and
problems.
1/ Buying used ff epay is ALWAYS risky: Besides the transformer
terms and cables, the main risk is the VERY fragile split ferrite
core in the jaws: This ceramic parts is thin crosssection and very
brittle.
Dropping the probe head A FEW INCHES on a had surfce can cause
hairline cracks in the core half.
2/ Hard to see the defect at first but your note is typical,
inconsistent perrformance as the probes is used.
3/ Mechanical is VERY carefully setup so the spring and TINY ball
beraing appy a specified pressure at the jaws to mate the mirror
polizshed core halvs.
Disassembly, fooling wih the sprin or (worse) loosisng the ball
beraing WILL result in bad colsure and inconsistent readings.
4/ Give away is a beatup probe plastic jaw, or dirty or scored
mirror ferrite jaw surface: Probe has been mistreated.
5/ Eben repair of the cable let alone the ferrite is very difficult
to succeed.
6/ We never use the old 134 amps as we have the correct P6021 and
P6022 TERM boxes (often lost when the probe is sild)
7/ Amp 134 DOEs give some benefits and sone prefer it.
8 The DC hall effect probes are very similar in construction and
same points apply.
9/ Test is simple:
Take 50 Ohm axial 1/4W resistor, connect with short RG174/U etc
with BNC to 50 Ohm pulse generator
Set for 2..10V peak, square wave.
Look at current wave over a wide range of PRF and tie scae.
To see the actual current just place a scope voltage probe across
the 50 Ohm r.
Bon Chance
Jon
Thus I = Vpeak/50
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WOW, Chuck great to see you jump in, agree with my notes?
how are you doing?
All fine here, jammed with planning and business for 2024
Have an absolutely fantastic day!
Jon
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On Mon, Feb 5, 2024 at 02:39 PM, Dave Wise wrote:
??? It's not the spring that stresses the plastic, it's the extra tension when you close the probe fully.? On my P6021, the slot at the end that the slider's tab engages broke.? I epoxied onto the nose a bit of sheet metal with an angle bend for the tab.? That was maybe ten years ago and it's holding fine, spring and all.
Hello Dave,
Perhaps I think I did not explain myself appropriately as I have to disagree that the spring pressure is not creating the stress fractures that I am seeing at the tip of the probe. The spring pushes on the upper sliding part (called ".SLIDE,TEST PROD:ACETAL 351-0174-00), which engages and rests into a small rectangular opening at the end of the lower part of the probe (called Body Assemble Probe Lower 204-0362-02), which basically holds and stops the other upper moving part in place putting pressure on that area. I can even see that by pushing the upper slide a bit further these tiny cracks at the tip start to open ever so slightly so that is why I decided to remove the spring. BTW the ball bearing is still in place, I only removed the spring. If you have a chance to look at the replaceable parts section of the P6022 probe manual (I got it from the Tekwiki site), on page 35 where the exploded parts view is shown that will hopefully clarify what I was trying to explain. For clarification I wanted to upload a picture of that page but it seems no attachments are allowed on postings.
But here is the manual:
https://w140.com/tek_p6022.pdf
Exploded parts view on page 35, and parts list on page 34. The part I need to replace would be that "Body Assemble Probe Lower 204-0362-02". If anyone has one of those, even a used decent looking one, I might be interested.
On Mon, Feb 5, 2024 at 02:39 PM, Dave Wise wrote:
??? I own a P6021 (LF 2nd gen) and a P6020 (HF 1st gen).? I discovered that the 134's LF COMP adjustment had to be quite different for those two.? After cursing the designer for not including two pots, I bought a second 134 so each probe has its own dedicated amplifier.
Not sure I follow. My 134 unit, and I think all of them, have a selector switch to choose the appropriate probe model, between P6019/21 on one side, and P6020/6022 probes on the other, as obviously one probe requires less gain that the other. There are also separate gain adjustment holes for each selection on the side of the unit. Not sure this is what you meant or I might be missing something, just in case it might be helpful, my 134 is serial number 8158.
Thank you.
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On Mon, Feb 5, 2024 at 02:39 PM, Dave Wise wrote:
I own a P6021 (LF 2nd gen) and a P6020 (HF 1st?gen).? I discovered that the 134's LF COMP adjustment had to be quite different for those two.? After cursing the designer for not including two pots, I bought a second 134 so each probe has its own dedicated amplifier.
?
Oops, ok I now understood that you where referring to was the LF COMP adjustment, as there is only one for all probe types, and not the gain adjustment. Agree given the switch selector for the probe model, guess they could have easily added another separate LF Comp control. Apologies for the mix up.
?
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look for passive small comp box designed for P6022, 134 amp is an pain
j
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I needed the low-frequency extension you get with the 134's active transresistance termination.
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Show quoted text
look for passive small comp box designed for P6022, 134 amp is an pain
j
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we use the DC HALL effect to 50 MHz tek probe and matching amp for LF DC work.
The small clamp on are never accurate at LF even with 134 amp
j
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Mike exactly, but AM503B is much improved over 503.
We use both P6302 and the giant P6303 gun for high current
Very useful for SMPS, low PRF current pulses.
But P6302 is very easy to break, and unrepairable, beware of used epay.
Jon
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Jon,
I'm curious why you have found that the AM503B is much improved compared to the AM503.?? The manuals show noise spec of the AM503B (with the P6302) being slightly better (<250uA RMS)? vs. <0.3mA "Tangentially measured" for the AM503. The bandwidth worse at 20MHz vs. 50MHz for the AM503 with P6302.
I suspect that you found in practical work the AM503B has been better.
Maybe I'm prejudiced because my AM503B with its internal microcontroller and annoying internal battery stopped working (even after battery replacement) while my all-analog AM503 is still cranking along.
John Hunt Portland, OR .?
| 1e.? | Re: Tek P6022 current probe
From:?Froggie the Gremlin
Date: Thu, 08 Feb 2024 18:36:05 PST
Mike exactly, but AM503B is much improved over 503.
We use both P6302 and the giant P6303 gun for high current
Very useful for SMPS, low PRF current pulses.
But P6302 is very easy to break, and unrepairable, beware of used epay.
Jon |
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John Hunt:
See the TekWiki for specs and manuals on all 3 versions.
The BW depends on r probe used and not the variations _/A/B.
The noise is a bit worse on AM503 than A/B. BW about same on all 3 for comparable porbes.
BW limit 20M on A/B and 5 MHz on 503.
(has links for all 3 for user man, CAL, schematics)
When the A/B 1.55 V silver oxide watch battery dies, you loose ,memory of CAL and last setup.
manuals say CAL is needed after exchange of battery.
Found all My 503A/B are intact, needed batteries. (SR389/390 Silver Oxide)
After replacement all came up fine and NO recal needed.
Tested on a 1T loop with 50 Ohm term resistor and 10 V PG, transient and CAL OK.
One of my probes A6302 rings a bit and needs cleaning or adjustment.
Will check the huge P6303 100 A guns next.
Enjoy,
Jon
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Froggie the Gremlin