Re: 54615B Agilent Scope Amplitude Low When Measuring 120V AC
If you use standard X10 'scope probes, one way to measure something like AC mains is to use both 'scope channels, set to ADD with one of the channels inverted.? This then gives a single trace on the 'scope which is in effect a differential measurement of the signal between the 2 probes.? With one probe on each side of the AC signal and the 'scope set to 5V/cm (and the probe earths 'earthed'), the sensitivity with a X10 probe is therefore 50V/cm, so 400V total, top to bottom of the screen. ? With 120V AC, I would expect the P:P signals to be ~340V, within the 400V total range of the 'scope screen. ? Just my 5p worth! ? 73, Mike, Mike Stevens, G8CUL/M0CUL/F4VRB. ?
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From: [email protected] On Behalf Of Robert G8RPI via groups.io
Sent: 16 November 2021 10:32
To: [email protected]
Subject: Re: [HP-Agilent-Keysight-equipment] 54615B Agilent Scope Amplitude Low When Measuring 120V AC? One thing about Neils post,
the "earth" lead on the 'scope probe is not their for safety. It's just for signal fidelity.
The resistance and current rating of the lead is not adequate to provide protection against shocks or fire. I've seen more than one 'sope lead literally smoking over the years when somone (not me) made a bad connection.
Robert G8RPI.
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Re: 54615B Agilent Scope Amplitude Low When Measuring 120V AC
One thing about Neils post,
the "earth" lead on the 'scope probe is not their for safety. It's just for signal fidelity.
The resistance and current rating of the lead is not adequate to provide protection against shocks or fire. I've seen more than one 'sope lead literally smoking over the years when somone (not me) made a bad connection.
Robert G8RPI.
|
Re: How do I use these PSU output covers?
I have a couple of these supplies. When I'm using thin cables I bring them out of the slots on the lower face of the cover (I also use remote sensing with thin cables).?
If you don't want remote sensing you still need to loop back the sense inputs under that cover, or you'll see a significant output voltage error. Fitted by default by HP, but sometimes they and the annoyingly difficult to find connector get lost.
On Tue, 16 Nov 2021 at 09:52, Dr. David Kirkby, Kirkby Microwave Ltd < drkirkby@...> wrote: On Tue, 16 Nov 2021 at 09:43, Dr. David Kirkby < drkirkby@...> wrote: I have an HP 6674A PSU (normally 60 V 35 A), but mine with an option that increases the voltage to 70 V, but drops the current to 30 A. The output terminals should be covered by a cover, a photograph of which I attach. I am trying to figure out how Agilent expects these to be used.?
Oops, I forgot to attach one of the photos.
Dr. David Kirkby, Kirkby Microwave Ltd, drkirkby@...Telephone 01621-680100./ +44 1621 680100 Registered in England & Wales, company number 08914892. Registered office: Stokes Hall Lodge, Burnham Rd, Althorne, Chelmsford, Essex, CM3 6DT, United Kingdom
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Re: How do I use these PSU output covers?
On Tue, 16 Nov 2021 at 09:43, Dr. David Kirkby < drkirkby@...> wrote: I have an HP 6674A PSU (normally 60 V 35 A), but mine with an option that increases the voltage to 70 V, but drops the current to 30 A. The output terminals should be covered by a cover, a photograph of which I attach. I am trying to figure out how Agilent expects these to be used.?
Oops, I forgot to attach one of the photos. -- Dr. David Kirkby, Kirkby Microwave Ltd, drkirkby@...Telephone 01621-680100./ +44 1621 680100 Registered in England & Wales, company number 08914892. Registered office: Stokes Hall Lodge, Burnham Rd, Althorne, Chelmsford, Essex, CM3 6DT, United Kingdom
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How do I use these PSU output covers?
I have an HP 6674A PSU (normally 60 V 35 A), but mine with an option that increases the voltage to 70 V, but drops the current to 30 A. The output terminals should be covered by a cover, a photograph of which I attach. I am trying to figure out how Agilent expects these to be used.?
It looks like there are areas on these which you can break away to give some sort of hole that is not round. I am using cables which are about 6 mm in diameter. I am not bothered about remote sensing, the smaller holes would do for m4 6 mm diameter cables, but one can not fit a grommet or cable grand as there is insufficient room inside (see internal picture). If instead I use the larger holes, I will not find a grommet or cable gland that will take cables as small as 6 mm diameter.?
I am quite tempted to just drill two holes in this, and put a couple of cable glands suitable for a 6 mm diameter cables. But I suspect that the plastic might shatter if I try drilling it.? Someone else said don’t bother with cable grands as this cover is too weak to take a good tug, so I might as well use grommets with? cable ties on the inside? to stop the cable pulling out. .?
I must be missing something, as Agilent seems to put a fair amount of effort into the design of his cover, but it seems virtually unusable to me.
Dave?
-- Dr. David Kirkby, Kirkby Microwave Ltd, drkirkby@...Telephone 01621-680100./ +44 1621 680100 Registered in England & Wales, company number 08914892. Registered office: Stokes Hall Lodge, Burnham Rd, Althorne, Chelmsford, Essex, CM3 6DT, United Kingdom
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Re: 54615B Agilent Scope Amplitude Low When Measuring 120V AC
You don't necessarily need isolated probes, you just need to have isolation between you and the test setup.
Please learn from my mistakes where I have fried probes and oscilloscopes. Here are some hard learned lessons:
1. If you aren't sure that your oscilloscope inputs are isolated then assume they are not. This is the correct assumption 99.99% of the time.
2. The ground lead on that probe is there protect you
3. The ground lead on the oscilloscope is also there to protect you
4. Resist the temptation to circumvent ground with isolation transformers for the oscilloscope power or by cutting the ground path.
Making a high fidelity high voltage measurement takes a bit of thought. The crudest method is to use 2 probe channels to make a crude differential probe. You connect the probe grounds together and not to the DUT. 1 probe goes to your signal and the other to your DUT ground. Then you subtract the two channels.
Better yet you can get a proper differential probe ($$) or a high voltage rated oscilloscope probe meant for this type of work ($$$). I personally prefer another option, using a battery powered oscilloscope ($-$$$) instead. These can be purchased with the same type of safety ratings as a DMM which a regulator oscilloscope could never achieve.
But to reiterate: the operator danger is when you are touching any part of the DUT or test setup. Avoid this when you can but setting up the measurement beforehand and then switch the DUT on safely.
Cheers,
Neil
On Mon, Nov 15, 2021, at 9:41 PM, Bostonman wrote:
As far as incorrect voltage, the 340V is pretty much spot on with the other oscilloscope, and the meter is a true RMS that is reading 120V AC.
So you're thinking that this scope has an acceptable error at this high voltage? This makes sense, and at least helps to know the scope isn't actually broken.
Isolated inputs is something I've never tinkered with, but have heard they should be used. Isolating equipment from the outlet is a concept I never grasped, and always been afraid of messing with it. Measuring line voltage was just for fun and not something I do often, but I guess it isn't the smartest thing to do.
Does a more affordable solution exist rather than $1k on that probe in the link?
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Re: 54615B Agilent Scope Amplitude Low When Measuring 120V AC
As far as incorrect voltage, the 340V is pretty much spot on with the other oscilloscope, and the meter is a true RMS that is reading 120V AC.
So you're thinking that this scope has an acceptable error at this high voltage? This makes sense, and at least helps to know the scope isn't actually broken.
Isolated inputs is something I've never tinkered with, but have heard they should be used. Isolating equipment from the outlet is a concept I never grasped, and always been afraid of messing with it. Measuring line voltage was just for fun and not something I do often, but I guess it isn't the smartest thing to do.
Does a more affordable solution exist rather than $1k on that probe in the link?
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So I was perusing the HPAK 6632B manuals and under performance testing it requires a "1:1 probe with an RF tip."? Elsewhere under PARD testing it says?
"Set the oscilloscope's bandwidth limit to 20 MHz and use an RF tip on the oscilloscope probe".??
My question is what exactly is an RF probe tip?
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Yes, there are some compatibility issues.? I have 1 pair of ears that won't work with the installed handles.? The cutout angle is too sharp.? These came extra in a bag with my 3456 meter and I was told they would work with the 850x gear.? They don't.
So I need to research the correct ears.? I have the original manuals for the VNA stack.? They should have the correct part numbers (I hope).? I just haven't had time to dig them out yet.
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Re: Sample preparation for Impedance Analyzer
Thanks Vladan. That paper will be useful. I also found the manual for the modern Keysight 16196A (851422.pdf download) to be useful.? Have you ever used the coaxial test fixture? It is coaxial as in 50 ohm impedance, I still do not know what the donuts are. Peter
Peter,
is a description of the measurement method and ratioanle.
Vladan
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Re: [TekScopes] Removing the Adhesive From Hell
This discussion (which is also on another list) is helpful. I have an antique microphone which had masking tape on part of the outside. The finish is crinkle black. I could never get the adhesive off. Since the part that has the residue comes off I will give it a test with hot water and Goo Gone. I will report my success (or lack of it) to the list.
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On 11/15/2021 3:33 PM, Chuck Harris wrote: Hot water is simply amazing.
Masking tape is a problem child. Its mastic
starts out
sticky, then progresses to gooey, and ends up dry and
crumbly.
I find that masking tape lets go if it is allowed to stay
wet. It could indicate a polar component to its mastic,
or simply be the paper backing losing integrity.
I tend to start with water and detergent if the item
is just grungy, as it cleans up dirt, coffee, and soda
stains very well.
I then work my way to the semi polar/non polar solvents,
like alcohol/water solutions. 91% IPA most of the time,
but there are times when 70% is just a little more polar,
and works better. 70% will dissolve sugar where 91%, not
so much.
Finally ending up in the non-polar solvents, like naptha,
which works really well on gummy lables.
Goo-gone works well, but make sure you keep it well shook
up. It tends to separate into oil and solvent layers.
I have had best luck using a spray cleaner on the dried on
mastic from masking tape.
If the masking tape's mastic has gone gooey, naptha works
best.
-Chuck Harris
On Mon, 15 Nov 2021 14:47:53 -0800 "Roy Thistle"
<roy.thistle@...> wrote:
On Mon, Nov 15, 2021 at 08:15 AM, n4buq wrote:
heat, I've found that pouring/soaking in boiling water will help
loosen some adhesives. Heat makes solvents (like water... the so called 'universal solvent')
dissolve compounds more completely. Yes... it's obvious; but, IMO
it's underutilised, as a cleaning method. Just hot water and soap
dissolves a lot of 'dirt' ... even if only eventually.
--
Richard Knoppow
dickburk@...
WB6KBL
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Re: Sample preparation for Impedance Analyzer
Peter,
is a description of the measurement method and ratioanle.
Vladan
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Re: [TekScopes] Removing the Adhesive From Hell
Hot water is simply amazing. Masking tape is a problem child. Its mastic starts out sticky, then progresses to gooey, and ends up dry and crumbly. I find that masking tape lets go if it is allowed to stay wet. It could indicate a polar component to its mastic, or simply be the paper backing losing integrity. I tend to start with water and detergent if the item is just grungy, as it cleans up dirt, coffee, and soda stains very well. I then work my way to the semi polar/non polar solvents, like alcohol/water solutions. 91% IPA most of the time, but there are times when 70% is just a little more polar, and works better. 70% will dissolve sugar where 91%, not so much. Finally ending up in the non-polar solvents, like naptha, which works really well on gummy lables. Goo-gone works well, but make sure you keep it well shook up. It tends to separate into oil and solvent layers. I have had best luck using a spray cleaner on the dried on mastic from masking tape. If the masking tape's mastic has gone gooey, naptha works best. -Chuck Harris On Mon, 15 Nov 2021 14:47:53 -0800 "Roy Thistle" <roy.thistle@...> wrote: On Mon, Nov 15, 2021 at 08:15 AM, n4buq wrote:
heat, I've found that pouring/soaking in boiling water will help
loosen some adhesives.
Heat makes solvents (like water... the so called 'universal solvent')
dissolve compounds more completely. Yes... it's obvious; but, IMO
it's underutilised, as a cleaning method. Just hot water and soap
dissolves a lot of 'dirt' ... even if only eventually.
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Re: Sample preparation for Impedance Analyzer
Those donuts have two O/D sizes but a selection of I/D for the holes Are these actually sample holders for the two sizes: 7mm diam x 20mm length 10mm diam x 20mm length (Outer Diameter and Inner Diameter. There are too many acronyms. I found CRT in a C++ Tutorial but it does not mean Cathode Ray Tube)
Thanks Dave; I found an Operation Note for the HP 16091A Cavity test fixture. It does not explain how to use it. There are a couple of vague paragraphs in the HP 4191A manual (page 3-50 in mine) but nothing on how to use this test fixture. These appear on Ebay for $1500 or more. Who buys or? uses them? There is more information in the 1980 Jan HP Journal than the 4191A manual, and some pictures of them in use.? I assume these are the pins to solder/connect to the sample but no explanation on preparing a sample.
This is the cavity. What are the donuts in the round container? Are these dielectric samples? Why do they have a hole in them? Has anyone seen/have a manual for this HP 16091A Coaxial Test Fixture? Is it coaxial as in an RF cavity? I don't think so because it is too small for 1 GHz.? I think it is a coaxial shield for minimum stray capacitance/inductance.
On Sun, Nov 14, 2021 at 9:33 PM Dave McGuire < mcguire@...> wrote: On 11/14/21 8:57 PM, peter bunge wrote:
> How are connections made to samples with granular surfaces? Any
> suggestions apart from sputtering?
> How about conductive paint (rear defroster repair, Permatex has two
> products)?
> How are samples prepared for an instrument like the HP4191A? Is there a
> document that covers the subject?
> What do the samples look like and what dimensinos? It does not appear to
> be in the 4191A manual.
> Is there anyone? with actual experience making up samples and measuring
> them?
> My interest is in measuring the properties of highly conductive samples
> at different frequencies.
? ?How about colloidal silver?? The kind that's used in electron
microscopy, not the kind that's used by "healing crystals" etc nutjobs.
? ? ? ? ? ? ?-Dave
--
Dave McGuire, AK4HZ
New Kensington, PA
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Re: [TekScopes] Removing the Adhesive From Hell
On Mon, Nov 15, 2021 at 08:15 AM, n4buq wrote:
heat, I've found that pouring/soaking in boiling water will help loosen some adhesives.
Heat makes solvents (like water... the so called 'universal solvent') dissolve compounds more completely.? Yes... it's obvious; but, IMO it's underutilised, as a cleaning method. Just hot water and soap dissolves a lot of 'dirt' ... even if only eventually.
|
Re: Sample preparation for Impedance Analyzer
Thanks Dave; I found an Operation Note for the HP 16091A Cavity test fixture. It does not explain how to use it. There are a couple of vague paragraphs in the HP 4191A manual (page 3-50 in mine) but nothing on how to use this test fixture. These appear on Ebay for $1500 or more. Who buys or? uses them? There is more information in the 1980 Jan HP Journal than the 4191A manual, and some pictures of them in use.? I assume these are the pins to solder/connect to the sample but no explanation on preparing a sample.
This is the cavity. What are the donuts in the round container? Are these dielectric samples? Why do they have a hole in them? Has anyone seen/have a manual for this HP 16091A Coaxial Test Fixture? Is it coaxial as in an RF cavity? I don't think so because it is too small for 1 GHz.? I think it is a coaxial shield for minimum stray capacitance/inductance.
On Sun, Nov 14, 2021 at 9:33 PM Dave McGuire < mcguire@...> wrote: On 11/14/21 8:57 PM, peter bunge wrote:
> How are connections made to samples with granular surfaces? Any
> suggestions apart from sputtering?
> How about conductive paint (rear defroster repair, Permatex has two
> products)?
> How are samples prepared for an instrument like the HP4191A? Is there a
> document that covers the subject?
> What do the samples look like and what dimensinos? It does not appear to
> be in the 4191A manual.
> Is there anyone? with actual experience making up samples and measuring
> them?
> My interest is in measuring the properties of highly conductive samples
> at different frequencies.
? ?How about colloidal silver?? The kind that's used in electron
microscopy, not the kind that's used by "healing crystals" etc nutjobs.
? ? ? ? ? ? ?-Dave
--
Dave McGuire, AK4HZ
New Kensington, PA
|
Re: 54615B Agilent Scope Amplitude Low When Measuring 120V AC
Robert makes a good point. Totally isolated equipment is safer for line voltage measurements.?
On Mon, Nov 15, 2021 at 1:01 PM Robert G8RPI via <robert8rpi= [email protected]> wrote: A suitable probe is
A simple accidential reversionof line and neutral with a standard probe will result in any or all the following possible outcomes:
Tripped earth fault breaker.
Fried probe cable.
Fried 'scope.
Electrocuted operator
Burnt down property
No matter how careful you are about personal safety, even normal surges and spikes on the mains supply cn be high enough to damage normal probes and your scope.
Note that the "mains rated" probes intended for handheld 'scopes have no advantage on a normal 'scope thay? are intended for 'scopes with fully isolated inputs.
Robert G8RPI.
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Re: 54615B Agilent Scope Amplitude Low When Measuring 120V AC
A suitable probe is
A simple accidential reversionof line and neutral with a standard probe will result in any or all the following possible outcomes:
Tripped earth fault breaker.
Fried probe cable.
Fried 'scope.
Electrocuted operator
Burnt down property
No matter how careful you are about personal safety, even normal surges and spikes on the mains supply cn be high enough to damage normal probes and your scope.
Note that the "mains rated" probes intended for handheld 'scopes have no advantage on a normal 'scope thay? are intended for 'scopes with fully isolated inputs.
Robert G8RPI.
|
Re: Help diagnosing 8593E possible YTO failure
I purchased a YTO from them and worked ok. I recommend to check the rest of instrument prior to change the YTO. This instrument perform a pll lock each sweep. If for any reason it fails a residual fm ?would appears. Its interesting that the instrument uses to pass the confidence test with this failure. I purchased an used 8593A-026 and I had the same problem. Sadly in my case was the YTO, I never known if the failure was on magnetizing coil & circuit or on the oscillator components I sent the instrument to HP Argentina (Agilent) representative for repair , they installed an 8593E YTO with is working up to now. I should have a picture but it happened on 2003 … believe me that its identical. ?
Regards, Patricio.?
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On Fri, Nov 12, 2021 at 6:04 PM Patricio A. Greco via <patricio_greco= [email protected]> wrote: That’s correct this is a como failure on that analyzers. Try to perform adjustments tasks on synthesizers ( samplers … and so) if it don’t fix the problem you will need a new oscillator .?
Thanks Patricio. Given that the problem occurs well before the synthesizers in the signal chain I'm going to go ahead and chalk this one up to a bad YTO. Unfortunate, but at least I didn't pay much for this 8593E.
Does anyone on the list have recommendations for YTO diagnosis and rebuild, especially since it seems Luis Cupido is no longer offering this service? Test-Cal Instruments on eBay purports to be able to rebuild them; does anyone have experience with them?
Thanks, Nick
? Ing. Patricio A. GrecoTaller Aeronáutico de Reparación 1B-349Organización de Mantenimiento Aeronáutico de la Defensa OMAD-001Gral. Martín Rodríguez 2159San Miguel (1663)Buenos AiresT:?+5411-4455-2557F:?+5411-4032-0072 ? Hi all,
Hi all,
I'm working on the old 8593E I picked up off eBay a few years back. It had the problem when I got it -- I figure the seller probably knew and didn't mention it, but caveat emptor and all that.
The problem manifests as extreme, sporadic phase noise. Like this: <image.png>
That's a relatively tame example, and occasionally it will wipe out the whole trace. It's all FM noise.
I spent a while digging around the analog interface board and it seems to be OK. One thing I noticed is that the FM coil drive diagnostic screen (measuring FM+) shows a flat line. That said, the analyzer sweeps just fine below 10MHz spans where the FM coil is active (albeit with noise), and a scope does show some low voltage on that (current-driven) coil line, so I think it's probably OK (given the FM coil R is 1.25 ohms with <150mA, how did the FM coil diag measurement ever hope to show it on the trace?). The noise didn't change when I disconnected the A25 counter/lock assembly.
I disconnected the FM coil drive and ran the YTO's output after the isolator into another spec an, and it shows the YTO exhibiting exactly the same noise. I don't have a current source on hand which is quiet enough to drive the main coil and really rule out the main coil driver on the analog board. The YTO seems to sweep OK across its range with good power (~+12dBm after the isolator and directional coupler).
Before I get too deep in the rabbit hole building a quiet current
source, is this behavior a known symptom of YTO failure on the 859xE? What are the odds this could be noise in the main coil driver or +15/-15/+5 power supplies to the YTO? They seem clean to my scope, but it's very difficult to get good mV/uV-level noise measurements. If it is the YTO, does it seem likely to be the dreaded wirebonded transistor, or the circuitry on the control board?
Nick
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Re: Help diagnosing 8593E possible YTO failure
Hello Nick,
I've good experiences with testcalinstruments on ebay, also another colleague
in our institute. Both YTOs we've purchased are running without any further
issues - both of them are rebuild units.
Best regards,
Stephan
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On Montag, 15. November 2021 20:02:30 CET you wrote: On Fri, Nov 12, 2021 at 6:04 PM Patricio A. Greco via groups.io
<patricio_greco@...> wrote:
That’s correct this is a como failure on that analyzers.
Try to perform adjustments tasks on synthesizers ( samplers … and so) if
it don’t fix the problem you will need a new oscillator . Thanks Patricio. Given that the problem occurs well before the synthesizers
in the signal chain I'm going to go ahead and chalk this one up to a bad
YTO. Unfortunate, but at least I didn't pay much for this 8593E.
Does anyone on the list have recommendations for YTO diagnosis and rebuild,
especially since it seems Luis Cupido is no longer offering this service?
Test-Cal Instruments on eBay purports to be able to rebuild them; does
anyone have experience with them?
Thanks,
Nick
Ing. Patricio A. Greco
Taller Aeronáutico de Reparación 1B-349
Organización de Mantenimiento Aeronáutico de la Defensa OMAD-001
Gral. Martín Rodríguez 2159
San Miguel (1663)
Buenos Aires
T: +5411-4455-2557
F: +5411-4032-0072
www.servicios-electronicos.com
On 12 Nov 2021, at 19:39, Nick Foster <bistromath@...> wrote:
?
Hi all,
Hi all,
I'm working on the old 8593E I picked up off eBay a few years back. It had
the problem when I got it -- I figure the seller probably knew and didn't
mention it, but *caveat emptor* and all that.
The problem manifests as extreme, sporadic phase noise. Like this:
[image: image.png]
That's a relatively tame example, and occasionally it will wipe out the
whole trace. It's all FM noise.
I spent a while digging around the analog interface board and it seems to
be OK. One thing I noticed is that the FM coil drive diagnostic screen
(measuring FM+) shows a flat line. That said, the analyzer sweeps just
fine
below 10MHz spans where the FM coil is active (albeit with noise), and a
scope does show some low voltage on that (current-driven) coil line, so I
think it's probably OK (given the FM coil R is 1.25 ohms with <150mA, how
did the FM coil diag measurement ever hope to show it on the trace?). The
noise didn't change when I disconnected the A25 counter/lock assembly.
I disconnected the FM coil drive and ran the YTO's output after the
isolator into another spec an, and it shows the YTO exhibiting exactly the
same noise. I don't have a current source on hand which is quiet enough to
drive the main coil and really rule out the main coil driver on the analog
board. The YTO seems to sweep OK across its range with good power (~+12dBm
after the isolator and directional coupler).
Before I get too deep in the rabbit hole building a quiet current source,
is this behavior a known symptom of YTO failure on the 859xE? What are the
odds this could be noise in the main coil driver or +15/-15/+5 power
supplies to the YTO? They seem clean to my scope, but it's very difficult
to get good mV/uV-level noise measurements. If it is the YTO, does it seem
likely to be the dreaded wirebonded transistor, or the circuitry on the
control board?
Nick
--
Mit freundlichen Grü?en,
Dr.-Ing. Stephan Massner
|
Dr. David Kirkby, Kirkby Microwave Ltd
Jeremy Nichols
Patricio A. Greco