Re: E4402B SA power problem - need DC socket connections
Thanks Robert.? That ties up with about 16.5V to chassis measured on that top pin.? The bottom pin seems to float.
I'll try it on DC and see if that makes any difference.? I think that there's some logic or a microprocessor in there that organises shutdown.
But I'm resigned to a shotgun cap change as this is a really lovely SA in excellent condition and I would like to get more use out of it!
I suspect that it's one of the caps round the startup/shutdown circuitry, but a refresh of a batch of caps may just sort it out.
Thanks for the clear plug info.
BTW does anyone know the correct manufacturer's plug type to match that socket for DC in?? I get lost in the Molex catralogue looking for things like that, and none of my stocks of connector parts matches it.
-Jeremy
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How to I disassemble the HP/Agilent 8495B attenuator ?
Hello,
?
I need to disassemble ?the HP/Agilent 8495B ?attenuator, there are no visible screws, how can I do it if I need to service the attenuator ?
?
Thanks in advance!
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Re: microscope / high magnification camera options for soldering, faults, and other examinations/inspections
Hi Steve,
Thanks for that advice. Why are 145 eyepieces better please? It seems 147 are very common.
Best regards,
Renaud
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Re: microscope / high magnification camera options for soldering, faults, and other examinations/inspections
Inasmuch as this is a vintage equipment group you might consider an American Optical AO570 with the model 145 eyepieces for about $100 on eBay. I can attest to the superb optics, with magnification from 7x to 40x. Illuminators are available for another $30-50. You do have to familiarize yourself with the models, various bases available and the eyepieces. I got an AO570 wit the wrong eyepieces included but got a correct pair model 145 separately. Gorgeous stereo view. The AO569 is a little cheaper but the optics have marginally less resolution. I’m happy I got the model 570.
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An Interesting find: HP Strobeline Demonstrator
I recently purchased this rare HP item off of eBay. It appears to be a trade show demonstration unit for selling HP's alphanumeric LED display modules. It is from 1970 (based on the date codes of the parts) and is made to a very high standard. As received it needed a very good cleaning to remove "residue of rodents" but once cleaned seemed to basically work without any repairs. The only remaining problem is a worn-out "DATA ENTER" switch but I found an exact replacement on eBay and will get that going as soon as the part arrives.
?
This same unit is on page 3 of the July 1970 HP Journal () and the corresponding article describes it in pretty good detail, although without schematics. All the ICs appear standard except for a mask ROM, and, of course, the HP display module itself.
I am posting this here to document this rare item's existence and in the hopes that a former HP employee may be able to provide some more information on it.
?
?
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Re: Keysight 33522a Binary Arb Files
Hi Alex, ? I used a demo version of Benchlink 33503A Pro to create triangle wave files in *.wvf, *.arb, and *.barb formats. ? For the 33522A, the waveform will appear on both channels simultaneously. ? Yves ? ? I found a threat for a 33210 where you created a testfie for a User. Is IT possible that you create a small barb File with all possible Parameters for my 33522a?
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HP 10248 series data probe IC part number
Does anyone have handy the HP part number on the interface IC used in the 10248 series of logic analyzer data probes? The manual on the probe has all part numbers listed except for the IC that is part of the PWB assembly. I once came across a HP part number 1820-0919 that was believed to be the number but it crosses to a Motorola MC1650L which is a dual A/D converter, an obviously wrong part.
Thanks,
Greg
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Re: E4421B Display Sorted
I'm glad you solved the problem and that I was at least a little bit helpful! Milan
About a year ago one of my E4421B signal generators developed a display contrast problem. I left it for a while and then decided to see what info i could find about the problem.
After a while i decided i needed the services of Milan for the CLIP details, this was neatly done (thanks Milan). This info also was left for a while and then i finally took the cover off to see what was happening. As previously reported Q601 had an open BE junction. Mmm strange. But prior to this i measured some weird voltages on the LT1170 regulator and even worse an unusual to me configuration, the ground tab is connected to the 1mH switching inductor.
So i confirmed the DAC was supplying a 0 to -10V control signal from the front panel-good but the output from the TL074 was jumpy as was the output from the LT1170 regulator with supplies of up to -46V being measured.
Q601 was replaced (not the best thing to do) and the display was back for a minute and then it all went wrong again. Working at the LT1170 was not easy due space and depth issues so i rebuilt the supply on stripboard to emulate the problem. So i couldn't get these weird varying voltages even thought the control signal was fine. Almost there so it was the Schottky diode CR607 that was the culprit.
The excess voltages explains the demise of Q601, C651 the 47 uf output capacitor was also replaced. I would suggest to any one with this problem to immediately connect a 24V zener across R625 the 2 watt 1K5 resistor and remove the 15 way flat ribbon going to the display? to avoid damaging it whilst affecting repairs as $350 is a high price for a new one
cheers
Geoff
GI0GDP
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HP list, the extension cables have been sold, Thanks for the responses, Gary WA2OMY ?
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About a year ago one of my E4421B signal generators developed a display contrast problem. I left it for a while and then decided to see what info i could find about the problem.
After a while i decided i needed the services of Milan for the CLIP details, this was neatly done (thanks Milan). This info also was left for a while and then i finally took the cover off to see what was happening. As previously reported Q601 had an open BE junction. Mmm strange. But prior to this i measured some weird voltages on the LT1170 regulator and even worse an unusual to me configuration, the ground tab is connected to the 1mH switching inductor.
So i confirmed the DAC was supplying a 0 to -10V control signal from the front panel-good but the output from the TL074 was jumpy as was the output from the LT1170 regulator with supplies of up to -46V being measured.
Q601 was replaced (not the best thing to do) and the display was back for a minute and then it all went wrong again. Working at the LT1170 was not easy due space and depth issues so i rebuilt the supply on stripboard to emulate the problem. So i couldn't get these weird varying voltages even thought the control signal was fine. Almost there so it was the Schottky diode CR607 that was the culprit.
The excess voltages explains the demise of Q601, C651 the 47 uf output capacitor was also replaced. I would suggest to any one with this problem to immediately connect a 24V zener across R625 the 2 watt 1K5 resistor and remove the 15 way flat ribbon going to the display? to avoid damaging it whilst affecting repairs as $350 is a high price for a new one
cheers
Geoff
GI0GDP
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Re: FS 11672A 8660 extension cable kit
Gary,
?
I will take the extender cable kit. Let me know how you to complete.
?
Thanks,
Russ
WA7MLW
?
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Re: Keysight 23522a Binary Arb Files
Hey Yves,
I found a threat for a 33210 where you created a testfie for a User. Is IT possible that you create a small barb File with all possible Parameters for my 33522a?
Thanks in advance Alex
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Would anyone have an example cal file they can share? I’d like to create one for my hardware
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Re: Cleaning N-tyoe cal kit
If you manage to separate the metallic parts form dielectrics , it is possible on older connectors. I recommend a solution of boiling water and sodium bicarbonate to clean the parts the process can take a couple of hours. Sodium bicarbonate is a known antiacid and its easy to get . It reverts the corrosion and is the best to save gold plated surfaces. Of coarse you can rework the surfaces with electroplating.? 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
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On 22 Mar 2025, at 22:23, Robert G8RPI via groups.io <robert8rpi@...> wrote:
? After lots of trials with several solvents over the years I've found the best solvent for decayed PU foam is 99% methanol.
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FS 11672A 8660 extension cable kit
HP list, with all the interest in 8660’s recently, I can offer this 11672A cable kit for sale. It is complete, but as expected the foam has deteriorated, everything will need to be cleaned. Hard to see but the cables and connectors are in very good condition, looks like it has not had much use. This is the kit to extend plug in’s, not mainframe board extenders. ??I used 8660’s for many years here, good piece of RF test equipment, but replaced with lighter weight/small size. $80.00 total shipped to your door, US only, ?L48. Gary WA2OMY
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Re: display tilt adjustment hp8591a
I have an HP8714 VNA here, that we used to cart around the
country servicing power amps.?? After one visit to a MRI place,
the entire display was at 45' tilt!
Eventually we degaussed the case (well, the entire instrument!)
using a Helmholtz coil, a 24V 5A transformer and a Variac!
"Normal" (non tilted) service was restored!
Some years later, the source module went intermittent, an OC
somewhere in the signal path.?? I got it for free as a result.?
Sometimes it fixes itself.? I need to find or make an extender for
that module.
"One Day"...
Dave 'KBV.
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Re: Cleaning N-tyoe cal kit
If you use methanol, please be extremely careful. Wear gloves, don't
inhale fumes, etc. Methanol poisoning is no joke. Read up on it
prior to use.
--Tom
--
Prof. Thomas H. Lee
Allen Ctr., Rm. 205
420 Via Palou Mall
Stanford University
Stanford, CA 94305-4070
On 3/22/2025 2:23 PM, Robert G8RPI via
groups.io wrote:
toggle quoted message
Show quoted text
After lots of trials with several solvents over the years
I've found the best solvent for decayed PU foam is 99% methanol.
|
Re: Cleaning N-tyoe cal kit
After lots of trials with several solvents over the years I've found the best solvent for decayed PU foam is 99% methanol.
|
Re: E4402B SA power problem - need DC socket connections
On original question +ve to top see image of mating connector viewed from "flat" side.  On PSU issue generally they are such a pig to get out and apart it is worth replacing all the small electrolytics. The big HV ones are generally OK. Just checking ESR is not enough. I'm not generally a fan of "shotgun" electrolytic replacement but decided to do it on the very similar PSU in my 8920a (worth looking at the 8920x PSU diagrams there aer some on the web). when I had it out following a main switch transistor failure. While all the caps looked OK and checked for in-circuit ESR (several are in parallel) 3 had started to leak th in one case the PCB was starting to burn.
?
Robert.
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Re: E4402B SA power problem - need DC socket connections
Power-down is now fairly random - anywhere from 2 to 10 minutes.? I've replaced the CPU board SnapHat with a much better one (3.2V vs 0.5V!) and that seems to cure some of the oddness on startup (data out of range etc).
But a secondhand psu is $500 and up!? BTW the SA powers up perfectly again if I hit the on-button straight away, so it's hopefully not some sort of heat fault.? Maybe I need to shotgun the caps in the psu, or at least check all ESRs properly.
If anyone has any ideas about this power supply repair please let me know!
-Jeremy
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Steve Holland
medasaro
Patricio A. Greco
