Re: HP 400E sticky needle
I would think that other glues might be more easily used.
For instance, a famous very old glue is milk. A drop of
milk will hold very well, but is also water soluble.
Milk is the original ingredient in white glues such as
Elmer's... which is why the bottle has a cow on it.
Back when I was brewing beer, I used milk to glue the labels
onto the bottles. I just put some in a saucer, and dipped
the label in, and onto the bottle.
I have a current meter that has the dial card flaking problem,
I think I will try a little milk on a soft brush..
-Chuck Harris
toggle quoted message
Show quoted text
On Sat, 17 Sep 2022 15:09:51 -0700 "bd139" <me@...> wrote: Well the Pritt stick melted in hot water did a really good job of the
peeling. Looks excellent! However it's still sticking. I will
disassemble it again tomorrow and investigate further.
Attachments:
IMG_2548.JPG:
/g/HP-Agilent-Keysight-equipment/attachment/129583/
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Re: Pozidriv screws on HP covers
Since nobody seems to have mentioned it, Pozidriv screws can be identified by a cross type screw slot, with a set of fine lines stamped in the head in between the crossed slots (a cross and a cross...). JIS have a single dot stamped in the head between two of the slots. Pozidriv screw slots have square sides, which makes it unlikely that the bit will cam out of the screw's slots... And, makes it incompatible with phillips screw drivers. To get the square sides on the driver bit, they have to use a narrower grinding wheel, which leaves 8 facets on the screwdriver (as opposed to the Phillips 4 facets.). JIS and pozidriv bits usually break when the torque is exceeded. You have been warned. Torx and square drive are the kings of readily available high torque screws. Allen is a distant second. -Chuck Harris On Sat, 17 Sep 2022 18:26:32 -0500 "Steve Holland via groups.io" <sholland@...> wrote: People: I keep learning useful stuff on these threads even when
looking at posts about equipment I don’t own. Pozidrive screws: Great
tip!
Steve
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HP 1661A Logic Analyzer Schematics
Does anyone have the schematics for the HP 1661A Logic Analyzer?? I found the service manual, but no schematics.
Best regards,?
Alex
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On Sun, Sep 18, 2022 at 01:22 AM, freshndaire wrote:
I would not call this unit hard to service or a poor mechanical design.? Pull the big aluminum hunk and you have lots of access!? The synthesizer module has 3 long bolts holding it in.? Remove the SMA Semi-rigid coax cable from the module's backplane then pull the 3 screws in the middle and you can lift the synth module and set it aside with the other cables plugged in IIRC.
So my memory served me right! Raymond
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Before I dive deeply into troubleshooting maybe someone can give me a direction to look into first.
I have a HP 432A with a downward drift. Same problem on all three mounts that I have, a HP 478A, a HP X486A, and a Micronetics TM-400. So I’m pretty sure it’s not the mount! The drift is slight on the 10 mW range but gets quite bad as you go down in ranges. The shunt regulator +7V and -13V outputs seem okay. The meter otherwise is working, the drift is the only problem.
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Re: Pozidrive screws on HP covers
People: I keep learning useful stuff on these threads even when looking at posts about equipment I don’t own. Pozidrive screws: Great tip!
Steve
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I used to work as a line tech on these back in 1980.? The things I most remember about them was the .01dB level accuracy and the millihertz frequency resolution were just amazing.? I also remember they were sometimes a nightmare to turn-on and calibrate on the line as they would have spurious oscillation and "wandering spur" issues that sometimes required adding additional ferrite beads that weren't on the schematics or BOM as most units didn't need them.? Also the fractional-N digital circuitry was a real bear to troubleshoot.? The good part was once you worked out the occasional issues, they were a very solid machine.? But there would be one now and then that was your nearly invincible enemy.
? The 3325A later came out with a lot of the Fractional-N circuitry on a single ASIC, I really envied the guys that worked on them.
? I would not call this unit hard to service or a poor mechanical design.? Pull the big aluminum hunk and you have lots of access!? The synthesizer module has 3 long bolts holding it in.? Remove the SMA Semi-rigid coax cable from the module's backplane then pull the 3 screws in the middle and you can lift the synth module and set it aside with the other cables plugged in IIRC.? There are even legs to set it on!? Don't block the honeycomb vents or run it flat out of the chassis, there is some power hungry digital in there.? Then you can much more easily access the power supply to probe more of it.? I only worked on new units for the most part so I don't know what fails after 40+ year.? I'd suspect wear out / age related issues and cracked solder joint failures on power devices.
? We had a test fixture with some load resistors for testing the supplies when there was a problem.? I would tend to do the power supply diagnostics (rarely needed) with the synth module disconnected to avoid damaging it while working the supplies.??
? There was a series of 4? troubleshooting videos, too long for me to want to watch but I think he had some power supply issues.? Search YouTube for 3335A repair if interested and you should find them.
? The 3335A was the unit that convinced me to move to the Integrated Circuit Wafer Fab later in 1980 and tackle high vacuum systems and all the dangerous voltages and chemicals.? I liked that work more than that wonderful but sometimes really hard to repair aluminum block of bleeding edge tech.? I also worked on the 3551A, the 3312A, and in the R&D lab on the 3314A for a while, plus some temporary work on other sources as needed.
Clay Scott
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Re: Pozidrive screws on HP covers
On Sat, 17 Sep 2022, vk2bea via groups.io wrote: All HP gear used Pozidriv screws, not Philips. May be there are some exclusions but as far as I can tell I have never seen that. I failed to realize, until recently, that the screws on the covers on many
HP instruments are Pozidrive and not Philips.
Had I looked more carefully I would have seen the X indicator but it was
only after I actually used a Pozidrive on one that I felt how much better
it was! Not surprisingly it's a much better / firmer fit.
Live and learn I guess. I'll never use a Philips on one again! --- * * KSI@home KOI8 Net < > The impossible we do immediately. * * Las Vegas NV, USA < > Miracles require 24-hour notice. * *
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Larry, You're right?and my apologies again to the members and moderators. I will approach this differently?next time (which is how I typically do it). Radu.?
On Sat, Sep 17, 2022 at 2:26 PM Larry McDavid < lmcdavid@...> wrote: I got them all but, Radu, you really should edit photos for image size
before sending them as Group emails. Remember that email attachments
incur about 30% overhead! Each email was 21 MB big. There are lots of
free image editors around...
Best wishes,
Larry McDavid W6FUB
Anaheim, California (SE of Los Angeles, near Disneyland)
On 9/17/2022 2:19 PM, Radu Bogdan Dicher wrote:
> Apologies if my attachments have been too large for some inboxes. Could
> anyone please confirm the message was received by at least some people
> and by the forum?
> Thank?you,
> Radu.
>
> On Sat, Sep 17, 2022, 2:09 PM Radu Bogdan Dicher via
> <> <vondicher=[email protected]
> <mailto:[email protected]>> wrote:
>
>? ? ?By "top PCB" I mean the one on the right side as one faces the rear
>? ? ?of the unit (A15), and "bottom PCB" the left side one (which is also
>? ? ?the one with the large PS caps) - A14.
>? ? ?Radu.
>
>? ? ?On Sat, Sep 17, 2022 at 1:59 PM Radu Bogdan Dicher via
>? ? ?<> <vondicher=[email protected]
>? ? ?<mailto:[email protected]>> wrote:
>
>? ? ? ? ?Still working on the PS disassembly procedure.
>? ? ? ? ?I removed two screws at the back:
>? ? ? ? ?image.png
>? ? ? ? ?And the top PCB started wiggling a bit, though it is still is
>? ? ? ? ?attached with two inaccessible screws:
>? ? ? ? ?image.png
>? ? ? ? ?As these are facing the row of shielded modules that goes from
>? ? ? ? ?front to back of unit.
>? ? ? ? ?image.png
>? ? ? ? ?I surely hope I don't have to hollow the entire unit just to get
>? ? ? ? ?the PS out?...
>? ? ? ? ?If I try from the other side, the side panel is also obstructing
>? ? ? ? ?access to a couple of screws:
>? ? ? ? ?image.png
>? ? ? ? ?The same screws seen from the inside of the unit:
>? ? ? ? ?image.png
>? ? ? ? ?The bottom PCB seems to be used as a card into a header:
>? ? ? ? ?image.png
>? ? ? ? ?So I assume this one may detach a little easier, though the caps
>? ? ? ? ?are placed in their own sleeves. Are those sleeves just sliding out?
>? ? ? ? ?Thank you for your insights!
>? ? ? ? ?Radu.
>
>
>? ? ? ? ?On Sat, Sep 17, 2022 at 1:43 PM Radu Dicher <vondicher@...
>? ? ? ? ?<mailto:vondicher@...>> wrote:
>
>? ? ? ? ? ? ?Well, further schematic errors... (thanks a ton to Ozan who
>? ? ? ? ? ? ?straightened me on this one). C2 and C4, as they "stand" on
>? ? ? ? ? ? ?the schematic, are opposite in polarity. The schematic is
>? ? ? ? ? ? ?incorrect:
>? ? ? ? ? ? ?image.png
>? ? ? ? ? ? ?C2 should be reversed from what the schematic says (positive
>? ? ? ? ? ? ?on bottom).
>? ? ? ? ? ? ?Hope this helps someone down the line.
>? ? ? ? ? ? ?Radu.
>
>? ? ? ? ? ? ?On Sat, Sep 17, 2022 at 12:03 PM Patricio A. Greco via
>? ? ? ? ? ? ? <>
>? ? ? ? ? ? ?<patricio_greco=[email protected] <mailto:[email protected]>>
>? ? ? ? ? ? ?wrote:
>
>? ? ? ? ? ? ? ? ?I’m sorry I’ve a little mixed the capacitor reference
>? ? ? ? ? ? ? ? ?numbers . You have >= 20v on C100 / 200 ? This is the
>? ? ? ? ? ? ? ? ?start. I had similar problems with my power supply. So I
>? ? ? ? ? ? ? ? ?decided to remove it and test the components one by one.
>? ? ? ? ? ? ? ? ?I recommend this procedure because it’s dangerous to
>? ? ? ? ? ? ? ? ?have the rest of instrument conected to a faulty power
>? ? ? ? ? ? ? ? ?supply. There are 30% less now but can go up , no much
>? ? ? ? ? ? ? ? ?because it’s has a great design but in my view keeps
>? ? ? ? ? ? ? ? ?being uncomfortable .
>
>? ? ? ? ? ? ? ? ?Is not difficult to remove the complete module .
>
>? ? ? ? ? ? ? ? ?Regards
>
>? ? ? ? ? ? ? ? ?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 <tel:+5411-4455-2557>
>? ? ? ? ? ? ? ? ?F: +5411-4032-0072 <tel:+5411-4032-0072>
>? ? ? ? ? ? ? ? ?
>? ? ? ? ? ? ? ? ?<>
>
>>? ? ? ? ? ? ? ? ?On 17 Sep 2022, at 15:21, Radu Bogdan Dicher
>>? ? ? ? ? ? ? ? ?<vondicher@... <mailto:vondicher@...>> wrote:
>>
>>? ? ? ? ? ? ? ? ??
>>? ? ? ? ? ? ? ? ?To prevent any confusion, when I said I am reading 40V
>>? ? ? ? ? ? ? ? ?instead of 55V, this is between the negative legs of
>>? ? ? ? ? ? ? ? ?C2 and C4. Not at either one's legs vs ground, or over
>>? ? ? ? ? ? ? ? ?either one.
>>? ? ? ? ? ? ? ? ?This replicates step 2 from Service Group 8 (p.8-F-1).
>>? ? ? ? ? ? ? ? ?There was no way to connect to what they're calling
>>? ? ? ? ? ? ? ? ?for ("the junction of R1 and CR2 and R2 and CR4").
>>? ? ? ? ? ? ? ? ?Hopefully this helps with the clarity of my empirical
>>? ? ? ? ? ? ? ? ?data.
>>? ? ? ? ? ? ? ? ?Radu.
>>
>>? ? ? ? ? ? ? ? ?On Sat, Sep 17, 2022 at 11:13 AM Radu Bogdan Dicher
>>? ? ? ? ? ? ? ? ?via <>
>>? ? ? ? ? ? ? ? ?<vondicher=[email protected]
>>? ? ? ? ? ? ? ? ?<mailto:[email protected]>> wrote:
>>
>>? ? ? ? ? ? ? ? ? ? ?Hi Patricio,
>>? ? ? ? ? ? ? ? ? ? ?One overall conclusion is that all rails are down
>>? ? ? ? ? ? ? ? ? ? ?by about 30% (mind you, the same rate). Given
>>? ? ? ? ? ? ? ? ? ? ?they're all referenced to the +15V rail, the
>>? ? ? ? ? ? ? ? ? ? ?running assumption is that something's wrong with
>>? ? ? ? ? ? ? ? ? ? ?the?+15V regulator.
>>? ? ? ? ? ? ? ? ? ? ?I see less than 1.8V over C2.
>>? ? ? ? ? ? ? ? ? ? ?Radu.
>>
>>? ? ? ? ? ? ? ? ? ? ?On Sat, Sep 17, 2022 at 10:15 AM Patricio A. Greco
>>? ? ? ? ? ? ? ? ? ? ?via <>
>>? ? ? ? ? ? ? ? ? ? ?<patricio_greco=[email protected]
>>? ? ? ? ? ? ? ? ? ? ?<mailto:[email protected]>> wrote:
>>
>>? ? ? ? ? ? ? ? ? ? ? ? ?Please note that the voltage outputs are : + -
>>? ? ? ? ? ? ? ? ? ? ? ? ?15 vdc , 5 vdc and -5.2 Vdc … If C2 has > 40
>>? ? ? ? ? ? ? ? ? ? ? ? ?Vdc is ok. Please take a look to power supply
>>? ? ? ? ? ? ? ? ? ? ? ? ?schematic …
>>
>>? ? ? ? ? ? ? ? ? ? ? ? ?image0.jpeg
>>
>>? ? ? ? ? ? ? ? ? ? ? ? ?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 <tel:+5411-4455-2557>
>>? ? ? ? ? ? ? ? ? ? ? ? ?F: +5411-4032-0072 <tel:+5411-4032-0072>
>>? ? ? ? ? ? ? ? ? ? ? ? ?
>>? ? ? ? ? ? ? ? ? ? ? ? ?<>
>>
>>>? ? ? ? ? ? ? ? ? ? ? ? ?On 17 Sep 2022, at 12:39, Radu Bogdan Dicher
>>>? ? ? ? ? ? ? ? ? ? ? ? ?<vondicher@...
>>>? ? ? ? ? ? ? ? ? ? ? ? ?<mailto:vondicher@...>> wrote:
>>>
>>>? ? ? ? ? ? ? ? ? ? ? ? ??
>>>? ? ? ? ? ? ? ? ? ? ? ? ?I whipped out my longest probes - an inspired
>>>? ? ? ? ? ? ? ? ? ? ? ? ?overstock purchase from maybe Anchor near
>>>? ? ? ? ? ? ? ? ? ? ? ? ?SF?... - (pictures added to album, hoping
>>>? ? ? ? ? ? ? ? ? ? ? ? ?they give some ideas to others get that deep
>>>? ? ? ? ? ? ? ? ? ? ? ? ?inside the belly of this unit) - and I am
>>>? ? ? ? ? ? ? ? ? ? ? ? ?getting 40V at the minus leg of C2 and C4 (my
>>>? ? ? ? ? ? ? ? ? ? ? ? ?probing points), vs. an expected 55V.
>>>? ? ? ? ? ? ? ? ? ? ? ? ?Interestingly, as soon as I power off the
>>>? ? ? ? ? ? ? ? ? ? ? ? ?unit, the voltage there jumps up to about
>>>? ? ? ? ? ? ? ? ? ? ? ? ?45V, and even raises a bit more as the unit
>>>? ? ? ? ? ? ? ? ? ? ? ? ?is standing powered off (5 minutes later I
>>>? ? ? ? ? ? ? ? ? ? ? ? ?measure about 47V...).
>>>
>>>? ? ? ? ? ? ? ? ? ? ? ? ?Continuing my investigation.
>>>? ? ? ? ? ? ? ? ? ? ? ? ?Radu.
>>>
>>>? ? ? ? ? ? ? ? ? ? ? ? ?On Sat, Sep 17, 2022 at 6:01 AM Radu Bogdan
>>>? ? ? ? ? ? ? ? ? ? ? ? ?Dicher via <>
>>>? ? ? ? ? ? ? ? ? ? ? ? ?<vondicher=[email protected]
>>>? ? ? ? ? ? ? ? ? ? ? ? ?<mailto:[email protected]>> wrote:
>>>
>>>? ? ? ? ? ? ? ? ? ? ? ? ? ? ?Thank you all for sharing your thoughts.
>>>
>>>? ? ? ? ? ? ? ? ? ? ? ? ? ? ?I tried sending some pictures yesterday
>>>? ? ? ? ? ? ? ? ? ? ? ? ? ? ?by replying to the email chain with
>>>? ? ? ? ? ? ? ? ? ? ? ? ? ? ?attachments, but in doing so I exceeded
>>>? ? ? ? ? ? ? ? ? ? ? ? ? ? ?the max size. I created a photo
>>>? ? ? ? ? ? ? ? ? ? ? ? ? ? ?album?instead:
>>>? ? ? ? ? ? ? ? ? ? ? ? ? ? ?/g/HP-Agilent-Keysight-equipment/album?id=278590
>>>? ? ? ? ? ? ? ? ? ? ? ? ? ? ?</g/HP-Agilent-Keysight-equipment/album?id=278590>.
>>>
>>>
>>>? ? ? ? ? ? ? ? ? ? ? ? ? ? ?Will keep investigating this morning. I'm
>>>? ? ? ? ? ? ? ? ? ? ? ? ? ? ?surprised?to not find some paragraphs on
>>>? ? ? ? ? ? ? ? ? ? ? ? ? ? ?removing (each) modules in their
>>>? ? ? ? ? ? ? ? ? ? ? ? ? ? ?troubleshooting sections (typically with
>>>? ? ? ? ? ? ? ? ? ? ? ? ? ? ?images), which I expect from an HP manual
>>>? ? ? ? ? ? ? ? ? ? ? ? ? ? ?(particularly component-level). Anyway,
>>>? ? ? ? ? ? ? ? ? ? ? ? ? ? ?that concludes my whining and will go
>>>? ? ? ? ? ? ? ? ? ? ? ? ? ? ?ahead and dig in there more vigorously.
>>>? ? ? ? ? ? ? ? ? ? ? ? ? ? ?Radu.
>>>
>>>? ? ? ? ? ? ? ? ? ? ? ? ? ? ?On Sat, Sep 17, 2022 at 5:25 AM Patricio
>>>? ? ? ? ? ? ? ? ? ? ? ? ? ? ?A. Greco via <>
>>>? ? ? ? ? ? ? ? ? ? ? ? ? ? ?<patricio_greco=[email protected]
>>>? ? ? ? ? ? ? ? ? ? ? ? ? ? ?<mailto:[email protected]>> wrote:
>>>
>>>? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?I have a HP3335A. I started to
>>>? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?experiment problems as cpu freeze and
>>>? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?leveling errors and I found
>>>? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?microscopic cracks on power supply
>>>? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?board also I removed the transistors
>>>? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?and found an anormal slope on
>>>? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?characteristic curves (this is
>>>? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?thermal deterioration). Replaced the
>>>? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?transistors and re-soldered the
>>>? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?complete board, Also I removed the
>>>? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?capacitors for test , these was ok .
>>>? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?Cleaned the contacts and mounted
>>>? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?again. After that work, instrument
>>>? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?started to work like never. It??s
>>>? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?very very flat, let me show you the
>>>? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?results. I attached the response
>>>? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?curves I measured. X Avis is
>>>? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?logarithmic starting @1 MHz , and Y
>>>? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?Axis is in dB relative to 1 MHz. I
>>>? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?used 3 different methods to measure.
>>>
>>>? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?Regards,
>>>
>>>? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?Ing. Patricio A. Greco
>>>? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?Taller Aeronáutico de Reparación 1B-349
>>>? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?Organización de
>>>? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?Mantenimiento?Aeronáutico de la
>>>? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?Defensa OMAD-001
>>>? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?Laboratorio de Calibración ISO
>>>? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?17025?AREA: RF/MW
>>>? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?Gral. Martín Rodríguez 2159
>>>? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?San Miguel (1663)
>>>? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?Buenos Aires
>>>? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?T: +5411-4455-2557
>>>? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?F: +5411-4032-0072
>>>? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?
>>>? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?<>
>>>
>>>
>>>
>>>>? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?On 17 Sep 2022, at 08:01, Harold
>>>>? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?Foster <halfoster@...
>>>>? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?<mailto:halfoster@...>> wrote:
>>>>
>>>>? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?Taking the assemblies loose is
>>>>? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?almost essential to troubleshooting
>>>>? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?the supply boards, but *very
>>>>? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?important:* You have to install a
>>>>? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?jumper to reconnect the ground - the
>>>>? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?boards are grounded through one of
>>>>? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?the brackets (the one to the bottom
>>>>? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?of the chassis if I remember
>>>>? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?correctly) and will be disconnected
>>>>? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?when it it taken loose.
>>>>
>>>>? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?Hal
>>>? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?WhatsApp Image 2022-07-21 at 3.19.42
>>>? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?PM.jpeg
>>>
>
|
Re: HP 400E sticky needle
You will probably find some of the flakes stuck in the meter movement. Worst case, you will find some steel filings stuck in the meter movement.
Cheers ????
Bruce
Quoting bd139 <me@...>:
toggle quoted message
Show quoted text
Well the Pritt stick melted in hot water did a really good job of the peeling. Looks excellent! However it's still sticking. I will disassemble it again tomorrow and investigate further.
|
Re: HP 400E sticky needle
Well the Pritt stick melted in hot water did a really good job of the peeling. Looks excellent! However it's still sticking. I will disassemble it again tomorrow and investigate further. 
|
Re: Pozidrive screws on HP covers
Is pozidriv better than hex, though? I've had dramatically lower
frustration using hex on most things I design (though torx
conceptually seems better and now its patent has expired, so I might
move in that direction)
|
Re: Pozidrive screws on HP covers
I have found keeping a PZ1 and a PZ2 Pozidriv drivers in close reach lets me get through almost any HP and a lot of Tek gear.
A bunch of 90's Tek gear will need Torx drivers too.
As for Japanese JIS 'plus drive' screws you can tell if you come across one as there is usually a dot punched into the head of the screw.
They have straight main flutes like a Pozidriv, but lack the extra smaller flutes characteristic to Pozidriv.
Here in Japan, both JIS and Philips are common.
People most often come across JIS when stripping out the heads of screws on older Japanese motorcycle carburettors...
Australia uses Philips mostly, but Pozidriv does exist here and there.
I used to come across it most commonly in circuit breakers when I was working as an electrician. The extra torque available was handy for getting the terminal nice and tight on the conductors.
|
Re: Pozidrive screws on HP covers
On Sat, Sep 17, 2022 at 11:33 PM, vk2bea wrote:
Pozidrive and not Philips.
That'd be Pozidriv and Phillips, not Pozidrive and Philips. Using a Phillips screwdriver on a Pozidriv screw causes excessive wear to the screwhead. Brands like HP/Agilent/Keysight and Tektronix almost exclusively use(d) Pozidriv screws. Raymond
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Re: Pozidrive screws on HP covers
Phillips head screws are used only in the United States and are poor indeed. Elsewhere, except in Japan, crosshead screws are PoziDriv.
Japanese cross head screws are most likely JIS, quite similar to PoziDriv. Using a Phillips driver in these screw will damage them.
Lots of PoziDriv screwdrivers are available on Amazon. You want sizes 1, 2 and 3.
If you ever work on Japanese electronics, you need a set of JIS drivers also.
Larry Sent via the Samsung Galaxy S10
toggle quoted message
Show quoted text
-------- Original message -------- From: Radu Bogdan Dicher <vondicher@...> Date: 9/17/22 2:40 PM (GMT-08:00) Subject: Re: [HP-Agilent-Keysight-equipment] Pozidrive screws on HP covers
Interesting. Maybe that's why I've had such a hard time trying to avoid ruining those as frequently as I had.? Do you have an image with a "pozidrive" tip? Radu.?
I failed to realize, until recently, that the screws on the covers on many HP instruments are Pozidrive and not Philips.
Had I looked more carefully I would have seen the X indicator but it was only after I actually used a Pozidrive on one that I felt how much better it was! Not surprisingly it's a much better / firmer fit.
Live and learn I guess. I'll never use a Philips on one again!
 ??
|
Re: Pozidrive screws on HP covers
Easy to find Pozi drive tools on ebay or at many specialty stores. I have and commonly use Pozi 0,1,2 drivers. It makes a REAL difference.
Cheers!
Bruce
Quoting Radu Bogdan Dicher <vondicher@...>:
toggle quoted message
Show quoted text
Interesting. Maybe that's why I've had such a hard time trying to avoid
ruining those as frequently as I had.
Do you have an image with a "pozidrive" tip?
Radu.
On Sat, Sep 17, 2022, 2:33 PM vk2bea via groups.io <vk2bea=
[email protected]> wrote:
I failed to realize, until recently, that the screws on the covers on many
HP instruments are Pozidrive and not Philips.
Had I looked more carefully I would have seen the X indicator but it was
only after I actually used a Pozidrive on one that I felt how much better
it was! Not surprisingly it's a much better / firmer fit.
Live and learn I guess. I'll never use a Philips on one again!
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Re: Pozidrive screws on HP covers
Interesting. Maybe that's why I've had such a hard time trying to avoid ruining those as frequently as I had.? Do you have an image with a "pozidrive" tip? Radu.?
I failed to realize, until recently, that the screws on the covers on many HP instruments are Pozidrive and not Philips.
Had I looked more carefully I would have seen the X indicator but it was only after I actually used a Pozidrive on one that I felt how much better it was! Not surprisingly it's a much better / firmer fit.
Live and learn I guess. I'll never use a Philips on one again!
 ??
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Pozidrive screws on HP covers
I failed to realize, until recently, that the screws on the covers on many HP instruments are Pozidrive and not Philips. Had I looked more carefully I would have seen the X indicator but it was only after I actually used a Pozidrive on one that I felt how much better it was! Not surprisingly it's a much better / firmer fit. Live and learn I guess. I'll never use a Philips on one again!  ??
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I got them all but, Radu, you really should edit photos for image size before sending them as Group emails. Remember that email attachments incur about 30% overhead! Each email was 21 MB big. There are lots of free image editors around...
Best wishes,
Larry McDavid W6FUB
Anaheim, California (SE of Los Angeles, near Disneyland)
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On 9/17/2022 2:19 PM, Radu Bogdan Dicher wrote: Apologies if my attachments have been too large for some inboxes. Could anyone please confirm the message was received by at least some people and by the forum?
Thank?you,
Radu.
On Sat, Sep 17, 2022, 2:09 PM Radu Bogdan Dicher via groups.io <> <vondicher@... <mailto:[email protected]>> wrote:
By "top PCB" I mean the one on the right side as one faces the rear
of the unit (A15), and "bottom PCB" the left side one (which is also
the one with the large PS caps) - A14.
Radu.
On Sat, Sep 17, 2022 at 1:59 PM Radu Bogdan Dicher via groups.io
<> <vondicher@...
<mailto:[email protected]>> wrote:
Still working on the PS disassembly procedure.
I removed two screws at the back:
image.png
And the top PCB started wiggling a bit, though it is still is
attached with two inaccessible screws:
image.png
As these are facing the row of shielded modules that goes from
front to back of unit.
image.png
I surely hope I don't have to hollow the entire unit just to get
the PS out?...
If I try from the other side, the side panel is also obstructing
access to a couple of screws:
image.png
The same screws seen from the inside of the unit:
image.png
The bottom PCB seems to be used as a card into a header:
image.png
So I assume this one may detach a little easier, though the caps
are placed in their own sleeves. Are those sleeves just sliding out?
Thank you for your insights!
Radu.
On Sat, Sep 17, 2022 at 1:43 PM Radu Dicher <vondicher@...
<mailto:vondicher@...>> wrote:
Well, further schematic errors... (thanks a ton to Ozan who
straightened me on this one). C2 and C4, as they "stand" on
the schematic, are opposite in polarity. The schematic is
incorrect:
image.png
C2 should be reversed from what the schematic says (positive
on bottom).
Hope this helps someone down the line.
Radu.
On Sat, Sep 17, 2022 at 12:03 PM Patricio A. Greco via
groups.io <>
<patricio_greco@... <mailto:[email protected]>>
wrote:
I’m sorry I’ve a little mixed the capacitor reference
numbers . You have >= 20v on C100 / 200 ? This is the
start. I had similar problems with my power supply. So I
decided to remove it and test the components one by one.
I recommend this procedure because it’s dangerous to
have the rest of instrument conected to a faulty power
supply. There are 30% less now but can go up , no much
because it’s has a great design but in my view keeps
being uncomfortable .
Is not difficult to remove the complete module .
Regards
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 <tel:+5411-4455-2557>
F: +5411-4032-0072 <tel:+5411-4032-0072>
www.servicios-electronicos.com
<>
On 17 Sep 2022, at 15:21, Radu Bogdan Dicher
<vondicher@... <mailto:vondicher@...>> wrote:
?
To prevent any confusion, when I said I am reading 40V
instead of 55V, this is between the negative legs of
C2 and C4. Not at either one's legs vs ground, or over
either one.
This replicates step 2 from Service Group 8 (p.8-F-1).
There was no way to connect to what they're calling
for ("the junction of R1 and CR2 and R2 and CR4").
Hopefully this helps with the clarity of my empirical
data.
Radu.
On Sat, Sep 17, 2022 at 11:13 AM Radu Bogdan Dicher
via groups.io <>
<vondicher@...
<mailto:[email protected]>> wrote:
Hi Patricio,
One overall conclusion is that all rails are down
by about 30% (mind you, the same rate). Given
they're all referenced to the +15V rail, the
running assumption is that something's wrong with
the?+15V regulator.
I see less than 1.8V over C2.
Radu.
On Sat, Sep 17, 2022 at 10:15 AM Patricio A. Greco
via groups.io <>
<patricio_greco@...
<mailto:[email protected]>> wrote:
Please note that the voltage outputs are : + -
15 vdc , 5 vdc and -5.2 Vdc … If C2 has > 40
Vdc is ok. Please take a look to power supply
schematic …
image0.jpeg
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 <tel:+5411-4455-2557>
F: +5411-4032-0072 <tel:+5411-4032-0072>
www.servicios-electronicos.com
<>
On 17 Sep 2022, at 12:39, Radu Bogdan Dicher
<vondicher@...
<mailto:vondicher@...>> wrote:
?
I whipped out my longest probes - an inspired
overstock purchase from maybe Anchor near
SF?... - (pictures added to album, hoping
they give some ideas to others get that deep
inside the belly of this unit) - and I am
getting 40V at the minus leg of C2 and C4 (my
probing points), vs. an expected 55V.
Interestingly, as soon as I power off the
unit, the voltage there jumps up to about
45V, and even raises a bit more as the unit
is standing powered off (5 minutes later I
measure about 47V...).
Continuing my investigation.
Radu.
On Sat, Sep 17, 2022 at 6:01 AM Radu Bogdan
Dicher via groups.io <>
<vondicher@...
<mailto:[email protected]>> wrote:
Thank you all for sharing your thoughts.
I tried sending some pictures yesterday
by replying to the email chain with
attachments, but in doing so I exceeded
the max size. I created a photo
album?instead:
/g/HP-Agilent-Keysight-equipment/album?id=278590
</g/HP-Agilent-Keysight-equipment/album?id=278590>.
Will keep investigating this morning. I'm
surprised?to not find some paragraphs on
removing (each) modules in their
troubleshooting sections (typically with
images), which I expect from an HP manual
(particularly component-level). Anyway,
that concludes my whining and will go
ahead and dig in there more vigorously.
Radu.
On Sat, Sep 17, 2022 at 5:25 AM Patricio
A. Greco via groups.io <>
<patricio_greco@...
<mailto:[email protected]>> wrote:
I have a HP3335A. I started to
experiment problems as cpu freeze and
leveling errors and I found
microscopic cracks on power supply
board also I removed the transistors
and found an anormal slope on
characteristic curves (this is
thermal deterioration). Replaced the
transistors and re-soldered the
complete board, Also I removed the
capacitors for test , these was ok .
Cleaned the contacts and mounted
again. After that work, instrument
started to work like never. It??s
very very flat, let me show you the
results. I attached the response
curves I measured. X Avis is
logarithmic starting @1 MHz , and Y
Axis is in dB relative to 1 MHz. I
used 3 different methods to measure.
Regards,
Ing. Patricio A. Greco
Taller Aeronáutico de Reparación 1B-349
Organización de
Mantenimiento?Aeronáutico de la
Defensa OMAD-001
Laboratorio de Calibración ISO
17025?AREA: RF/MW
Gral. Martín Rodríguez 2159
San Miguel (1663)
Buenos Aires
T: +5411-4455-2557
F: +5411-4032-0072
www.servicios-electronicos.com.ar
<>
On 17 Sep 2022, at 08:01, Harold
Foster <halfoster@...
<mailto:halfoster@...>> wrote:
Taking the assemblies loose is
almost essential to troubleshooting
the supply boards, but *very
important:* You have to install a
jumper to reconnect the ground - the
boards are grounded through one of
the brackets (the one to the bottom
of the chassis if I remember
correctly) and will be disconnected
when it it taken loose.
Hal WhatsApp Image 2022-07-21 at 3.19.42
PM.jpeg
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Hello All, I recently acquired a HP 8340B. Unfortunately it's not fully functional. There is a problem when it crosses bands 3 and 4. But before going in the troubleshooting, I noticed that an internal cover is missing, see attached picture. As there is a warning saying "do not operate for an extended periods without this cover to ensure proper cooling", I would like to reinstall it. Does anyone of you would have one to sell or knows where I could buy one? I also noticed that one screw is missing for the external bottom cover. I think this is a typical screw for HP instruments covers, not specific for the 8340B. If someone has one to sell, I would appreciate it.  
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Steve J. Noll, WA6EJO
Steve Holland
Sergey Kubushyn
Jared Cabot
vk2bea
