Re: 8566B Attenuator Service
On Tue, Sep 17, 2024 at 02:53 PM, Jinxie wrote:
can't think of any scenario where I would even dream of using that stuff
About half million tons of the stuff, used around the U.S. annually, for something.
They used HF to etch quartz crystals during WWII
AFAIK is was something like 5% solution of HF.
Women did it, using open tanks... AFAIR
In that zinc plated, vacuum tube, culture... and given the angst of the war.. I doubt safety was a top priority.
Yet, I don't know how much of a? problem it created, and whether, or not, there were slashes causing injury.
?
Fisher ships 50%
Most university labs have it.
Sometimes accidents happen
But it's mostly in industrial settings, I think... where fatalities occur.
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On Tuesday 17 September 2024 11:26:03 pm Jim via groups.io wrote: I'd love to see other benches! On another forum I've seen some "benches" that were to die for personal warehouses of wonderfully organized storage and spacious workbenches.
Some of the minimalist benches were exceedingly clever uses of small spaces and very inspirational too. It's been a long time since I've seen it, but I *think* that there's a bench underneath all of that "stuff" in the other room... -- Member of the toughest, meanest, deadliest, most unrelenting -- and ablest -- form of life in this section of space, ?a critter that can be killed but can't be tamed. ?--Robert A. Heinlein, "The Puppet Masters" - Information is more dangerous than cannon to a society ruled by lies. --James M Dakin
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Re: 8566B Attenuator Service
On Tue, Sep 17, 2024 at 04:25 PM, Mark Bielman wrote:
It would not attack your flesh (went right through) but dissolved your bone.
It does penetrate the skin, which is a barrier for entry into the body, beyond that organ.
Not sure how it 'dissolves' bone... if you mean it brings bone into solution, with body water... as HF forms calcium, and magnesium fluoride percipitates... in the body.
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Re: 8566B Attenuator Service
On Wed, Sep 18, 2024 at 04:51 AM, Robert G8RPI wrote:
official treatment is calcium gluconate gel
?
calcium gluconate gel is widely available, and used for lots of other things
Should always be on hand if handling HF, especially 1%,5% or 10% solutions.
Hospital emergency, and cluing in the doctors, is a must.
?
for significant splashes of 50% HF, used in etching fabs, I don't know how much the gel? helps?
they do start giving it intravenously ASAP
?
Sadly some woman in a Taiwan fab? died, several hours later, after having splashed 50% HF on her legs.
Significant exposure seems to mostly lead to death.
?
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Re: HP 141T Power Supply Help Needed
I can't see what could destroy Q15, except perhaps C18 shorting.
Dave Wise
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I don't have a HV probe currently, but its on my shopping list.? ? I'm going to go with 0v at the moment though, given the state of Q15.??
I guess I'm just wondering?if I should expect other damage to have occurred when this part failed.? ??
I will replace Q15 this week, get a probe and report back though!?
On Wed, Sep 18, 2024 at 10:59?AM Michael Bafaro via
<m.bafaro= [email protected]> wrote:
Bill,
?
Q15 is the FET that is in the HV regulator circuit.? The gate to the other leads will read open if the ohm meter is connected to back bias the junction.? The question is what voltage is present at the control
grid of the CRT?? If you have a high voltage probe you can measure it directly at the green lead on the PCB that goes to the CRT socket.? I measured -2580.? What voltage do you see??
?
Mike
?
?
Checking things out last night in the LV side of the HV supply, I saw on the edge of Q15 a small delamination. Very tough to see in that tight space but just enough to warrant further?investigation.? ?I pulled Q15 and a sizable chunk
was blown out and barely hanging on, so it's physically OPEN between pins 1 and 2.
I've ordered a replacement.? Anything else to be concerned with in this area in such a situation?? Q13 and 14 don't seem to be damaged as far as I can tell, at this time.? ??
?
On Tue, Sep 17, 2024 at 9:27?AM Bill Berzinskas via <bberzinskas=[email protected]> wrote:
Probably not related strictly to the PSU, so happy to make a new thread if needed.? ?
I've gone over the A5 board at a high level.? ?Checked all the test points and all but #7 appear to be as expected on the scope.
One of the schematics has voltages at the wiring pins, and those also look ok.? ?I have not checked per-node voltage within the circuit yet.? ??
Is this "fairly conclusive evidence" that A5 is generally OK?? ?I don't want to dwell on it, I'd thought that maybe Blanking or Pulse were having issues?
but now i'm thinking not.? ??
More power supply related, I don't see any oscillation on the HV oscillator.? ?The labelled 7v is closer to 12v so I'm thinking the problem is around Q13, 14 or 15.? Q15 looks kind?of not good, seeing .1v breakdown with a DMM diode test in-circuit.? ?I know
thats?not the best test, but it does seem to work for most of the other transistors I've tested.??
?
The worst bugs make the instrument diverge from the schematic, often in ways that would look like nonsense if you drew it there.
"From over 40 years of fault finding and repair experience in a wide range of electronic products, not just instrumentation,
the weirdest symptoms often have a really simple root cause!"
This has been my experience as well! Makes it very easy to go down a rabbit hole. Which is why I always do a thorough visual
inspection first. Also checking mechanical components of switches, pots, etc. Giving them a good clean right off the bat and testing those first can save you a lot of headache.
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Re: 8566B Attenuator Service
On Wed, Sep 18, 2024 at 04:51 AM, Robert G8RPI wrote:
HF is a calcium seeker.
when a solution of HF penetrates the skin, from a splash for example... it dissociates into fluorine ions.
those react with both calcium and magnesium ions, to significantly reduce their concentrations in the body.
that interferes with muscle, and nerve function
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Re: 8566B Attenuator Service
On Wed, Sep 18, 2024 at 04:51 AM, Robert G8RPI wrote:
HF is a calcium seeker.
HF penetrates the skin, and dissociates, in body water, to form fluoride ions.
Fluoride ions bond with both calcium and magnesium ions...reducing their availability in the body, for import muscle, and nerve functions.
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Re: 8566B Attenuator Service
I'm sure your hardness scale figures are correct, Roy. But the particle size at 1500 grit is so tiny you'd need a microscope to spot them. So hardness is only part of it in this context.
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Re: 8566B Attenuator Service
Dimethyl mercury is one of the worst compounds IME. Even if you were protective gloves, it can't save you from a single drop of the stuff. This unfortunately lady became the poster girl for organo-metallic chemistry lab safety after she became exposed in this way. It took a year to kill her and she died a terrible death. Terrifying stuff...
?
https://en.wikipedia.org/wiki/Karen_Wetterhahn
?
?
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Re: 8566B Attenuator Service
On Tue, Sep 17, 2024 at 02:27 PM, Jim Ford wrote:
dissolve glass
Stuff people used to have around the house, could dissolve glass.
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Re: 8566B Attenuator Service
On Tue, Sep 17, 2024 at 02:24 PM, Jinxie wrote:
I'm surprised the 1500 grit paper did!
Aluminum Oxide...hardness of about 9 on the Mohs hardness scale...glass, hardness of around 5-6.
Silicon carbide... even harder.
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Re: GPIB scripting software?
Thank you very much. I will give it a try.
Cheers!
H
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On 17/09/2024 19:17, Chuck Harris wrote: # 7854.py - try out some gpib data collection using the Prologix gpib-usb controller
#
import os
import termios
import serial
import time
def gpib_init() :
ser.write("++mode 1\r")
time.sleep(0.1)
ser.write("++ifc\r")
time.sleep(0.1)
ser.write("++auto 0\r")
time.sleep(0.1)
ser.write("++eoi 0\r")
time.sleep(0.1)
def gpib_read(addr):
ser.write("++addr " + str(addr) + "\r")
time.sleep(0.1)
ser.write("++read eoi\r")
return ser.readline()
def gpib_write(addr,gpibstr):
ser.write("++addr " + str(addr) + "\r")
time.sleep(0.1)
ser.write(gpibstr + "\r")
#
# test program...
#
ser = serial.Serial('/dev/ttyUSB0',rtscts=0,timeout=1)
ser.write("++ver\r")
print ser.readline()
gpib_init()
gpib_write(10,"ID?\r")
print "ID= " + gpib_read(10) + "\r"
gpib_write(10,"VMDR\r")
gpib_write(10,"HMDB\r")
gpib_write(10,"STORED\r")
gpib_write(10,"1 0 2 4 >P/W AVG10\r")
gpib_read(10)
gpib_write(10,"SENDX\r")
time.sleep(4)
print "X=" + gpib_read(10) + "\r"
print "X=" + gpib_read(10) + "\r"
-Chuck Harris
On Tue, 17 Sep 2024 12:20:03 +0200 "Harke Smits via groups.io"
<yrrah@...> wrote:
Do you have a simple example at hand? I used the Prologix adapter in
the past with KE5FX toolbox but never with pyvisa. I prefer to use
Python as I want more data processing options than available with the
kit.
H
On 17/09/2024 04:27, Andrew Hakman wrote:
Python + prologix adapter is about as simple, portable, and
dependency free as it gets.
Open the port with the python "serial" library, and send direct
GPIB commands to it.
No need to install any drivers or i/o libraries, basically just
plug and play!
On Mon, Sep 16, 2024 at 12:25?AM Anders via groups.io
<> <anders.gustafsson@...> wrote:
I do the same with my own Prologix-clone
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Nice shop !!! The 8902 is the best !!?
Ing. Patricio A. Greco
Taller Aeron¨¢utico de Reparaci¨®n 1B-349
Organizaci¨®n de Mantenimiento?Aeron¨¢utico de la Defensa OMAD-001
Laboratorio de Calibraci¨®n ISO 17025?AREA: RF/MW?
Gral. Mart¨ªn Rodr¨ªguez 2159
San Miguel (1663)
Buenos Aires
T: +5411-4455-2557
F: +5411-4032-0072
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A neet and compact layout. I had some equipment to shop carts after running out of roo on my bench. That made it easier to take to the Ca lab as well.
On Wed, Sep 18, 2024 at 9:11?AM Harold Foster via <halfoster= [email protected]> wrote: Welcome! Since it seems the thing to share lab pictures:
?
<PXL_20240918_094009580_b.jpg>
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Re: HP 141T Power Supply Help Needed
I don't have a HV probe currently, but its on my shopping list.? ? I'm going to go with 0v at the moment though, given the state of Q15.??
I guess I'm just wondering?if I should expect other damage to have occurred when this part failed.? ??
I will replace Q15 this week, get a probe and report back though!?
On Wed, Sep 18, 2024 at 10:59?AM Michael Bafaro via <m.bafaro= [email protected]> wrote: Bill, ? Q15 is the FET that is in the HV regulator circuit.? The gate to the other leads will read open if the ohm meter is connected to back bias the junction.? The question is what voltage is present at the control grid of the CRT?? If you have a high voltage probe you can measure it directly at the green lead on the PCB that goes to the CRT socket.? I measured -2580.? What voltage do you see?? ? Mike ? ? Checking things out last night in the LV side of the HV supply, I saw on the edge of Q15 a small delamination. Very tough to see in that tight space but just enough to warrant further?investigation.? ?I pulled Q15 and a sizable chunk was blown out and barely hanging on, so it's physically OPEN between pins 1 and 2.
I've ordered a replacement.? Anything else to be concerned with in this area in such a situation?? Q13 and 14 don't seem to be damaged as far as I can tell, at this time.? ?? ? On Tue, Sep 17, 2024 at 9:27?AM Bill Berzinskas via <bberzinskas=[email protected]> wrote: Probably not related strictly to the PSU, so happy to make a new thread if needed.? ?
I've gone over the A5 board at a high level.? ?Checked all the test points and all but #7 appear to be as expected on the scope.
One of the schematics has voltages at the wiring pins, and those also look ok.? ?I have not checked per-node voltage within the circuit yet.? ??
Is this "fairly conclusive evidence" that A5 is generally OK?? ?I don't want to dwell on it, I'd thought that maybe Blanking or Pulse were having issues?
but now i'm thinking not.? ??
More power supply related, I don't see any oscillation on the HV oscillator.? ?The labelled 7v is closer to 12v so I'm thinking the problem is around Q13, 14 or 15.? Q15 looks kind?of not good, seeing .1v breakdown with a DMM diode test in-circuit.? ?I know thats?not the best test, but it does seem to work for most of the other transistors I've tested.??
? The worst bugs make the instrument diverge from the schematic, often in ways that would look like nonsense if you drew it there.
"From over 40 years of fault finding and repair experience in a wide range of electronic products, not just instrumentation, the weirdest symptoms often have a really simple root cause!" This has been my experience as well! Makes it very easy to go down a rabbit hole. Which is why I always do a thorough visual inspection first. Also checking mechanical components of switches, pots, etc. Giving them a good clean right off the bat and testing those first can save you a lot of headache.
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Jim, ? Nice lab!? I sent a picture of your lab to my daughter in Santa Clarita and she wants to know where you worked in the LA area (we assume).? I have a similar lab as I worked for Motorola in Schaumburg IL. ? Mike ?
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From: [email protected] < [email protected]> On Behalf Of Jim Ford Sent: Tuesday, September 17, 2024 4:22 PM To: [email protected]Subject: Re: [HP-Agilent-Keysight-equipment] Introduction ? Nice lab, Jim!? Another Jim here.? Here's my garage lab.? Jim Ford, Laguna Hills, California, USA? ? On Tue, Sep 17, 2024 at 1:36 PM, Jim via groups.io I was just approved to join in the fun here. For background info: ?- overall years using HP RF test equipment: approximately 49? ?- currently own 23 items of mostly RF related HP test equipment including Spec Ans, RF sig gens, VNA etc. ?- ?23 years for Microwave Links, Cellular Network Engineering and Cellular Core Network Performance
?-? 13 years at NASA/JPL in Communications Systems Research Currently maintaining a government radio repeater system Picture is of the home lab before I added the HP8924Cand HP3478A into the stack. The bench surface is rarely this uncluttered!
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Re: HP 141T Power Supply Help Needed
Bill, ? Q15 is the FET that is in the HV regulator circuit.? The gate to the other leads will read open if the ohm meter is connected to back bias the junction.? The question is what voltage is present at the control grid of the CRT?? If you have a high voltage probe you can measure it directly at the green lead on the PCB that goes to the CRT socket.? I measured -2580.? What voltage do you see?? ? Mike ?
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From: [email protected] < [email protected]> On Behalf Of Bill Berzinskas Sent: Wednesday, September 18, 2024 9:41 AM To: [email protected]Subject: Re: [HP-Agilent-Keysight-equipment] HP 141T Power Supply Help Needed ? Checking things out last night in the LV side of the HV supply, I saw on the edge of Q15 a small delamination. Very tough to see in that tight space but just enough to warrant further?investigation.? ?I pulled Q15 and a sizable chunk was blown out and barely hanging on, so it's physically OPEN between pins 1 and 2.
I've ordered a replacement.? Anything else to be concerned with in this area in such a situation?? Q13 and 14 don't seem to be damaged as far as I can tell, at this time.? ?? ? On Tue, Sep 17, 2024 at 9:27?AM Bill Berzinskas via <bberzinskas=[email protected]> wrote: Probably not related strictly to the PSU, so happy to make a new thread if needed.? ?
I've gone over the A5 board at a high level.? ?Checked all the test points and all but #7 appear to be as expected on the scope.
One of the schematics has voltages at the wiring pins, and those also look ok.? ?I have not checked per-node voltage within the circuit yet.? ??
Is this "fairly conclusive evidence" that A5 is generally OK?? ?I don't want to dwell on it, I'd thought that maybe Blanking or Pulse were having issues?
but now i'm thinking not.? ??
More power supply related, I don't see any oscillation on the HV oscillator.? ?The labelled 7v is closer to 12v so I'm thinking the problem is around Q13, 14 or 15.? Q15 looks kind?of not good, seeing .1v breakdown with a DMM diode test in-circuit.? ?I know thats?not the best test, but it does seem to work for most of the other transistors I've tested.??
? The worst bugs make the instrument diverge from the schematic, often in ways that would look like nonsense if you drew it there.
"From over 40 years of fault finding and repair experience in a wide range of electronic products, not just instrumentation, the weirdest symptoms often have a really simple root cause!" This has been my experience as well! Makes it very easy to go down a rabbit hole. Which is why I always do a thorough visual inspection first. Also checking mechanical components of switches, pots, etc. Giving them a good clean right off the bat and testing those first can save you a lot of headache.
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I agree. My typical layout is similar - a radial (90/45/0/-45/-90) distribution of shelving and tall carts that are all within easy reach (3'-6') of any project. Due to the projects as the picture was taken, that distribution was disturbed, but given most of those are wheeled, it's easy to put back once feasible. It's a deliberate setup.? Radu.? On Wed, Sep 18, 2024 at 7:36?AM Michael A. Terrell via <terrell.michael.a= [email protected]> wrote:
A neet and compact layout. I had some equipment to shop carts after running out of roo on my bench. That made it easier to take to the Ca lab as well.
On Wed, Sep 18, 2024 at 9:11?AM Harold Foster via <halfoster= [email protected]> wrote: Welcome! Since it seems the thing to share lab pictures:
?
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Re: HP 141T Power Supply Help Needed
Checking things out last night in the LV side of the HV supply, I saw on the edge of Q15 a small delamination. Very tough to see in that tight space but just enough to warrant further?investigation.? ?I pulled Q15 and a sizable chunk was blown out and barely hanging on, so it's physically OPEN between pins 1 and 2.
I've ordered a replacement.? Anything else to be concerned with in this area in such a situation?? Q13 and 14 don't seem to be damaged as far as I can tell, at this time.? ??
On Tue, Sep 17, 2024 at 9:27?AM Bill Berzinskas via <bberzinskas= [email protected]> wrote: Probably not related strictly to the PSU, so happy to make a new thread if needed.? ?
I've gone over the A5 board at a high level.? ?Checked all the test points and all but #7 appear to be as expected on the scope.
One of the schematics has voltages at the wiring pins, and those also look ok.? ?I have not checked per-node voltage within the circuit yet.? ??
Is this "fairly conclusive evidence" that A5 is generally OK?? ?I don't want to dwell on it, I'd thought that maybe Blanking or Pulse were having issues?
but now i'm thinking not.? ??
More power supply related, I don't see any oscillation on the HV oscillator.? ?The labelled 7v is closer to 12v so I'm thinking the problem is around Q13, 14 or 15.? Q15 looks kind?of not good, seeing .1v breakdown with a DMM diode test in-circuit.? ?I know thats?not the best test, but it does seem to work for most of the other transistors I've tested.??
The worst bugs make the instrument diverge from the schematic, often in ways that would look like nonsense if you drew it there.
"From
over 40 years of fault finding and repair experience in a wide range of electronic products, not just instrumentation, the weirdest symptoms often have a really simple root cause!"
?
This
has been my experience as well! Makes it very easy to go down a rabbit hole. Which is why I always do a thorough visual inspection first. Also checking mechanical components of switches, pots, etc. Giving them a good clean right off the bat and testing those
first can save you a lot of headache.
?
-Frank
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A neet and compact layout. I had some equipment to shop carts after running out of roo on my bench. That made it easier to take to the Ca lab as well.
On Wed, Sep 18, 2024 at 9:11?AM Harold Foster via <halfoster= [email protected]> wrote: Welcome! Since it seems the thing to share lab pictures:
?
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Fine, I'll bite.?
Only visible is the left side of the active part of my bench - pic from a few weeks ago, with the projects then, as I'm too comfortable in my living room arm chair right now (where "armchair diagnostics," or PCB designs, and other similar things happen...) to walk over and take a new pic... A little messier than usual, but you know... entropy!?
None of the many units sitting idle (including power supplies, Jim!), and only about half of my metrology standards are visible in this pic. On the eclecticism part of it all, you can see my 11x17 printer for schematics, FM antenna atop, and even my fully mechanical, automatic, handwatch. I decided there's enough chips tracking me!?
I promise you, once I'm wrapped into something at this bench, miraculously, a few square inches or - awe! - square feet materialize and I'm going forward.? Radu.?
On Tue, Sep 17, 2024 at 8:43?PM Frank Mashockie via <fmashockie= [email protected]> wrote: Welcome Jim! Here's my bench.? A lab within a lab (work as an in-house engineer for a biotech company). ? 
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Jinxie
Patricio A. Greco
Michael A. Terrell
