Hi thanks for the reply, I think part of the connector may be missing, I have moved house a few times , with the back panel hanging of the unit? from when I was investigating the power socket issue. This is what led to the cable being pulled out of the connector. I will have a close look and see what I may be able to do when the power connector gets here.
Also my eyesight and steady hands are not what they used to be.
Do the documents indicate which colour wire is pin 1?
?I need to blow up the manuals more to be able to read them
|
You know, if it's not broken too badly, you can reattach the IDC into the ribbon cable manually by slowly and carefully jamming the leads against the forks in the connector. Put the connector in a vise or other secure holder, and align the ribbon cable carefully to be sure of the right pinning, with the forks in a fresh spot on the insulation. Then use a broad flat screwdriver tip or a piece of sheet stock to gradually push the lines into the forks. Start between the rows of forks, and run back and forth across from one edge of the cable to the other, each time pushing the insulation a bit deeper until punched through. Then push the areas farther out from centerline a little at a time until it's reasonably flat and thoroughly punched through all around. If the plastic cover is intact you can attach it and squeeze it tight, or epoxy it on if necessary.
?
If it's messed up so much such that the forks can't be used, you can with some artful lead prepping just solder each one to its corresponding fork directly. This old-school stuff is big enough that a steady hand and decent vision can get the job done, and there aren't all that many lines - I think 20 or 24 max. Use a small iron, and pre-tin the lead ends and forks.
?
Ed
|
Hi all, working on my 8656B sig gen, and managed to break the IDC Centronics connector , so the cable is no longer attached. Is there a suitable replacement available taht is not too ex[ensive. Have to replace teh mains socket as smoke came out, still waiting on that, and it cost over $86Aus? from RS on its own.I don't want to spend more than the device is worth to fix it, not that I am likely to use this port
?
Wayne
VK2WDE
|
Re: HP 54512B (pair) repair
Jim - a lot of Elmers out there, it turns out...
Radu
Nope, Radu, a cable tie would require labor to install (“costs too much” in suit-speak).? Cheaper to glue it down.? I had a mechanical engineer coworker years ago with the nickname Elmer because he wanted to glue everything!? Ha!
Jim
> On Mar 3, 2025, at 1:31?PM, Razvan Popescu via <yo8ryr=[email protected]> wrote:
>
> ?Hi Radu,
>
> If you have a hot air desoldering station try to see if the heat will
> soften the glue/resin. Use low temp first and increase it slowly.
> Monitor the heat on the arm with an infrared thermometer in the same
> time not to melt the arm.
>
> Regards,
> Razvan
>
>> On 03/03/2025 22:17, Radu Bogdan Dicher via wrote:
>> Thank you, Mike.
>>
>> In terms of removing the arm from the switch stub (see pics enclosed a
>> few messages down), where HP decided to use this brown resin to glue
>> them together (completely unnecessary, in my opinion - how about a cable
>> tie or something easy to remove and replace?...), what would be some
>> recommendations in handling this? Specifically, safely and non-
>> destructively detaching the arm from the stub. The arm is marked:
>> "SPREAD JAWS TO INSTALL AND REMOVE," but due to the resin, that was just
>> about impossible upon my examination when doing this.
>>
>>? * Can anyone determine or have some educated guess regarding what sort
>>? ? of glue or resin that'd be? I tried seeing if I could scrape it or
>>? ? shatter it off, to no avail. It's tough and very hardened in place.
>>? ? Much harder than either of the two plastics it joins.
>>? * Solvents? I'd be pretty weary using liquid chemicals over the main
>>? ? board, but maybe something is recommended and safe to use in a
>>? ? situation like this.
>>? * What else would work? I assume others may have had this problem and
>>? ? came up with some good solutions.
>>
>> Thank you,
>> Radu.
>>
>> On Mon, Mar 3, 2025 at 8:32?AM Michael Bafaro via <http://
>> > <m.bafaro=[email protected]
>> <mailto:[email protected]>> wrote:
>>
>>? ? Radu,____
>>
>>? ? __ __
>>
>>? ? I wish you luck finding a replacement for the line filter and
>>? ? switch.____
>>
>>? ? __ __
>>
>>? ? Mike____
>>
>>? ? __ __
>>
>>? ? *From:*[email protected] <mailto:HP-Agilent-
>>? ? [email protected]> <HP-Agilent-Keysight-
>>? ? [email protected] <mailto:HP-Agilent-Keysight-
>>? ? [email protected]>> *On Behalf Of *Radu Bogdan Dicher via
>>? ? <>
>>? ? *Sent:* Monday, March 3, 2025 10:23 AM
>>? ? *To:* [email protected] <mailto:HP-Agilent-
>>? ? [email protected]>
>>? ? *Subject:* Re: [HP-Agilent-Keysight-equipment] HP 54512B (pair)
>>? ? repair____
>>
>>? ? __ __
>>
>>? ? Mike,____
>>
>>? ? This is unrelated with the issues I'm having with the -12V rail.
>>? ? When disassembling/reassembling the scope, the EMI Filter (more
>>? ? specifically, its built-in switch) and the HP arm/button broke
>>? ? apart. I can now either try to find replacements, or just
>>? ? replace the EMI Filter with a unit having the switch accessible from
>>? ? the back of the scope (this type is relatively easy to find) and
>>? ? disable the actuation of the front button. ____
>>
>>? ? Radu. ____
>>
>>? ? __ __
>>
>>? ? On Mon, Mar 3, 2025 at 8:16?AM Michael Bafaro via <http://
>>? ? > <m.bafaro=[email protected]
>>? ? <mailto:[email protected]>> wrote:____
>>
>>? ? ? ? Radu,____
>>
>>? ? ? ? ____
>>
>>? ? ? ? The pictures you sent appear to be the AC line filter (EMI) and
>>? ? ? ? the power switch and perhaps the line fuse.? If one of the
>>? ? ? ? supplies is off and the others are working, then the problem is
>>? ? ? ? somewhere else. ____
>>
>>? ? ? ? ____
>>
>>? ? ? ? The display is a standard magnetic deflected CRT.? I worked in
>>? ? ? ? that group years ago at Motorola.____
>>
>>? ? ? ? ____
>>
>>? ? ? ? Mike Bafaro ____
>>
>>? ? ? ? ____
>>
>>? ? ? ? *From:*[email protected] <mailto:HP-
>>? ? ? ? [email protected]> <HP-Agilent-Keysight-
>>? ? ? ? [email protected] <mailto:HP-Agilent-Keysight-
>>? ? ? ? [email protected]>> *On Behalf Of *Radu Bogdan Dicher via
>>? ? ? ? <>
>>? ? ? ? *Sent:* Sunday, March 2, 2025 7:14 PM
>>? ? ? ? *To:* [email protected] <mailto:HP-
>>? ? ? ? [email protected]>
>>? ? ? ? *Subject:* Re: [HP-Agilent-Keysight-equipment] HP 54512B (pair)
>>? ? ? ? repair____
>>
>>? ? ? ? ____
>>
>>? ? ? ? Two steps forward, one step back (one and a half?). ____
>>
>>? ? ? ? ____
>>
>>? ? ? ? While other things have been progressing, the power switch
>>? ? ? ? stopped working once I put most of the unit back together. I
>>? ? ? ? enclose some pictures, but it's a typical flip flop type where a
>>? ? ? ? pin prods and finds two different locations between the two
>>? ? ? ? states ON/OFF. I guess I can either look for a replacement (does
>>? ? ? ? anyone have one?), or try to repair it. Repairing something like
>>? ? ? ? this hasn't been something I've had a lot of luck with - if
>>? ? ? ? anyone has some good tips, I'll take them happily - and then
>>? ? ? ? there's also the way the longitudinal arm (actuating the
>>? ? ? ? pressing of the button on the front panel all the way to the
>>? ? ? ? back) is supposed to be handled. It seems to be glued with some
>>? ? ? ? hardened resin or something similar. In retrospect, though the
>>? ? ? ? SM doesn't mention this, I think the arm should be detached
>>? ? ? ? before removing the rear panel and moving it around. It puts too
>>? ? ? ? much pressure and torque on the switch to take this easily and
>>? ? ? ? not get damaged. ____
>>
>>? ? ? ? ____
>>
>>? ? ? ? Thank you for any pointers. ____
>>
>>? ? ? ? Radu. ____
>>
>>? ? ? ? ____
>>
>>? ? ? ? On Sun, Mar 2, 2025 at 3:20?PM Radu Bogdan Dicher via
>>? ? ? ? <> <vondicher=[email protected]
>>? ? ? ? <mailto:[email protected]>> wrote:____
>>
>>? ? ? ? ? ? Razvan,____
>>
>>? ? ? ? ? ? Thank you very much, this is very helpful. ____
>>
>>? ? ? ? ? ? I've managed to rig a load - I had a couple of 1ohm/10W
>>? ? ? ? ? ? Vishay RS10s (bulletproof, in my experience), and it looks
>>? ? ? ? ? ? like the -12V rail is MIA because of something going on in
>>? ? ? ? ? ? the PS. If I can confirm this, this would be great news (as
>>? ? ? ? ? ? opposed to tracking some failed tantalum decoupler or
>>? ? ? ? ? ? something else on the main board....). ____
>>
>>? ? ? ? ? ? Radu. ____
>>
>>? ? ? ? ? ? ____
>>
>>? ? ? ? ? ? On Sun, Mar 2, 2025 at 2:51?PM Razvan Popescu via
>>? ? ? ? ? ? <> <yo8ryr=[email protected]
>>? ? ? ? ? ? <mailto:[email protected]>> wrote:____
>>
>>? ? ? ? ? ? ? ? Hi Radu,
>>
>>? ? ? ? ? ? ? ? I think the PSU in all 545xx series was made by Boschert
>>? ? ? ? ? ? ? ? Inc. and
>>? ? ? ? ? ? ? ? someone already reverse engineered it. I attached the file.
>>
>>? ? ? ? ? ? ? ? I hope it helps.
>>
>>? ? ? ? ? ? ? ? Regards,
>>? ? ? ? ? ? ? ? Razvan
>>
>>? ? ? ? ? ? ? ? On 02/03/2025 23:33, Radu Bogdan Dicher via
>>? ? ? ? ? ? ? ? <> wrote:
>>? ? ? ? ? ? ? ? ?> Going back to my -12V rail issue, the SM advises
>>? ? ? ? ? ? ? ? loading the 5.20V rail
>>? ? ? ? ? ? ? ? ?> with a 2ohm/25W resistor. The only way I can put
>>? ? ? ? ? ? ? ? something similar
>>? ? ? ? ? ? ? ? ?> together with what I have at hand is using these
>>? ? ? ? ? ? ? ? dummy loads I am using
>>? ? ? ? ? ? ? ? ?> when repairing audio amplifiers, which are a pair of
>>? ? ? ? ? ? ? ? 8ohm/100W non-
>>? ? ? ? ? ? ? ? ?> inductive resistors. By paralleling them I can load
>>? ? ? ? ? ? ? ? the 5.20V rail with
>>? ? ? ? ? ? ? ? ?> a 4ohm resistor.
>>? ? ? ? ? ? ? ? ?> What are some thoughts regarding whether this would
>>? ? ? ? ? ? ? ? be a suitable load
>>? ? ? ? ? ? ? ? ?> for the PS? I think the PS just needs a low ohmic
>>? ? ? ? ? ? ? ? load of sufficient
>>? ? ? ? ? ? ? ? ?> dissipation capacity and it should crank itself up to
>>? ? ? ? ? ? ? ? nominal, but maybe
>>? ? ? ? ? ? ? ? ?> there's an aspect I'm overlooking.
>>? ? ? ? ? ? ? ? ?> Thank you,
>>? ? ? ? ? ? ? ? ?> Radu.
>>? ? ? ? ? ? ? ? ?>
>>? ? ? ? ? ? ? ? ?> On Sun, Mar 2, 2025 at 1:52?PM Radu Bogdan Dicher via
>>? ? ? ? ? ? ? ? <> <http://
>>? ? ? ? ? ? ? ? <http://%0b>> <>>
>>? ? ? ? ? ? ? ? <vondicher=[email protected]
>>? ? ? ? ? ? ? ? <mailto:[email protected]> <mailto:[email protected]
>>? ? ? ? ? ? ? ? <mailto:[email protected]>>>
>>? ? ? ? ? ? ? ? ?> wrote:
>>? ? ? ? ? ? ? ? ?>
>>? ? ? ? ? ? ? ? ?>? ? ?One of the two scopes is completely disassembled
>>? ? ? ? ? ? ? ? - head exploding
>>? ? ? ? ? ? ? ? ?>? ? ?emoji - and I have the old battery desoldered
>>? ? ? ? ? ? ? ? after confirming it's
>>? ? ? ? ? ? ? ? ?>? ? ?fully depleted.
>>? ? ? ? ? ? ? ? ?>
>>? ? ? ? ? ? ? ? ?>? ? ?I enclose pics with what I'm using for
>>? ? ? ? ? ? ? ? replacement. I probably would
>>? ? ? ? ? ? ? ? ?>? ? ?have been fine going with a 2032 type, but the
>>? ? ? ? ? ? ? ? 2430 I ended up
>>? ? ? ? ? ? ? ? ?>? ? ?fitting just right (maybe a bit snug), and the
>>? ? ? ? ? ? ? ? pins of the holder
>>? ? ? ? ? ? ? ? ?>? ? ?actually match the PCB eyelets. So all is good.
>>? ? ? ? ? ? ? ? ?>
>>? ? ? ? ? ? ? ? ?>? ? ?I couldn't figure out what exactly was the
>>? ? ? ? ? ? ? ? original battery model,
>>? ? ? ? ? ? ? ? ?>? ? ?as it's not legible even after removing the top
>>? ? ? ? ? ? ? ? tab, but its
>>? ? ? ? ? ? ? ? ?>? ? ?diameter is a bit over 23mm.
>>? ? ? ? ? ? ? ? ?>? ? ?I think this should work OK.
>>? ? ? ? ? ? ? ? ?>
>>? ? ? ? ? ? ? ? ?>? ? ?Back to the actual troubleshooting now!
>>? ? ? ? ? ? ? ? ?>? ? ?Radu.
>>? ? ? ? ? ? ? ? ?>
>>? ? ? ? ? ? ? ? ?>? ? ?On Fri, Feb 28, 2025 at 6:21?PM Roy J. Tellason,
>>? ? ? ? ? ? ? ? Sr. via <>
>>? ? ? ? ? ? ? ? ?>? ? ?< <>>
>>? ? ? ? ? ? ? ? <roy=[email protected]
>>? ? ? ? ? ? ? ? <mailto:[email protected]>
>>? ? ? ? ? ? ? ? ?>? ? ?<mailto:[email protected]
>>? ? ? ? ? ? ? ? <mailto:[email protected]>>> wrote:
>>? ? ? ? ? ? ? ? ?>
>>? ? ? ? ? ? ? ? ?>? ? ? ? ?On Thursday 27 February 2025 04:09:31 pm Radu
>>? ? ? ? ? ? ? ? Bogdan Dicher via
>>? ? ? ? ? ? ? ? ?> <> <
>>? ? ? ? ? ? ? ? <>> wrote:
>>? ? ? ? ? ? ? ? ?>? ? ? ? ? > One other unfortunate effect of the spot-
>>? ? ? ? ? ? ? ? welding of the top
>>? ? ? ? ? ? ? ? ?>? ? ? ? ?tab is that the
>>? ? ? ? ? ? ? ? ?>? ? ? ? ? > battery code is not visible. I can
>>? ? ? ? ? ? ? ? probably destroy the
>>? ? ? ? ? ? ? ? ?>? ? ? ? ?battery once out,
>>? ? ? ? ? ? ? ? ?>? ? ? ? ? > and read the CRxyzt battery code, but
>>? ? ? ? ? ? ? ? would anyone have good
>>? ? ? ? ? ? ? ? ?>? ? ? ? ?info offhand
>>? ? ? ? ? ? ? ? ?>? ? ? ? ? > on it?
>>? ? ? ? ? ? ? ? ?>
>>? ? ? ? ? ? ? ? ?>? ? ? ? ?You might find bits of this useful:
>>? ? ? ? ? ? ? ? ?>
>>? ? ? ? ? ? ? ? ?>
>>? ? ? ? ? ? ? ? <>
>>? ? ? ? ? ? ? ? <https://
>>? ? ? ? ? ? ? ? <https://%0b>>
>>? ? ? ? ? ? ? ? List_of_battery_sizes <
>>? ? ? ? ? ? ? ? List_of_battery_sizes>>
>>? ? ? ? ? ? ? ? ?>
>>? ? ? ? ? ? ? ? ?>? ? ? ? ?Scroll down to where they discuss coin and
>>? ? ? ? ? ? ? ? button cells:
>>? ? ? ? ? ? ? ? ?>
>>? ? ? ? ? ? ? ? ?>? ? ? ? ?"IEC designation numbers indicate the
>>? ? ? ? ? ? ? ? physical dimensions of the
>>? ? ? ? ? ? ? ? ?>? ? ? ? ?cylindrical cell. Cells less than one
>>? ? ? ? ? ? ? ? centimeter in height are
>>? ? ? ? ? ? ? ? ?>? ? ? ? ?assigned four-digit numbers, where the first
>>? ? ? ? ? ? ? ? two digits are the
>>? ? ? ? ? ? ? ? ?>? ? ? ? ?diameter in millimeters, while the last two
>>? ? ? ? ? ? ? ? digits are the
>>? ? ? ? ? ? ? ? ?>? ? ? ? ?height in tenths of millimeters. Taller cells
>>? ? ? ? ? ? ? ? are assigned five-
>>? ? ? ? ? ? ? ? ?>? ? ? ? ?digit numbers, where the first two digits are
>>? ? ? ? ? ? ? ? the diameter in
>>? ? ? ? ? ? ? ? ?>? ? ? ? ?millimeters, followed by the last three
>>? ? ? ? ? ? ? ? digits indicating the
>>? ? ? ? ? ? ? ? ?>? ? ? ? ?height in tenths of millimeters."
>>? ? ? ? ? ? ? ? ?>
>>? ? ? ? ? ? ? ? ?>? ? ? ? ?So the size of the battery will give you the
>>? ? ? ? ? ? ? ? info that you need.
>>? ? ? ? ? ? ? ? ?>
>>? ? ? ? ? ? ? ? ?>? ? ? ? ?--
>>? ? ? ? ? ? ? ? ?>? ? ? ? ?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
>>? ? ? ? ? ? ? ? ?>
>>? ? ? ? ? ? ? ? ?>
>>? ? ? ? ? ? ? ? ?>
>>? ? ? ? ? ? ? ? ?>
>>? ? ? ? ? ? ? ? ?>
>>? ? ? ? ? ? ? ? ?>
>>
>>
>>
>>? ? ? ? ? ? ? ? ____
>>
>>? ? __
>>
>
>
>
>
>
>
|
Re: HP 54512B (pair) repair
Nope, Radu, a cable tie would require labor to install (“costs too much” in suit-speak). Cheaper to glue it down. I had a mechanical engineer coworker years ago with the nickname Elmer because he wanted to glue everything! Ha!
Jim
toggle quoted message
Show quoted text
On Mar 3, 2025, at 1:31?PM, Razvan Popescu via groups.io <yo8ryr@...> wrote:
?Hi Radu,
If you have a hot air desoldering station try to see if the heat will
soften the glue/resin. Use low temp first and increase it slowly.
Monitor the heat on the arm with an infrared thermometer in the same
time not to melt the arm.
Regards,
Razvan
On 03/03/2025 22:17, Radu Bogdan Dicher via groups.io wrote:
Thank you, Mike.
In terms of removing the arm from the switch stub (see pics enclosed a
few messages down), where HP decided to use this brown resin to glue
them together (completely unnecessary, in my opinion - how about a cable
tie or something easy to remove and replace?...), what would be some
recommendations in handling this? Specifically, safely and non-
destructively detaching the arm from the stub. The arm is marked:
"SPREAD JAWS TO INSTALL AND REMOVE," but due to the resin, that was just
about impossible upon my examination when doing this.
* Can anyone determine or have some educated guess regarding what sort
of glue or resin that'd be? I tried seeing if I could scrape it or
shatter it off, to no avail. It's tough and very hardened in place.
Much harder than either of the two plastics it joins.
* Solvents? I'd be pretty weary using liquid chemicals over the main
board, but maybe something is recommended and safe to use in a
situation like this.
* What else would work? I assume others may have had this problem and
came up with some good solutions.
Thank you,
Radu.
On Mon, Mar 3, 2025 at 8:32?AM Michael Bafaro via groups.io <
groups.io> <m.bafaro@...
<mailto:[email protected]>> wrote:
Radu,____
__ __
I wish you luck finding a replacement for the line filter and
switch.____
__ __
Mike____
__ __
*From:*[email protected] <mailto:HP-Agilent-
[email protected]> <HP-Agilent-Keysight-
[email protected] <mailto:HP-Agilent-Keysight-
[email protected]>> *On Behalf Of *Radu Bogdan Dicher via
groups.io <>
*Sent:* Monday, March 3, 2025 10:23 AM
*To:* [email protected] <mailto:HP-Agilent-
[email protected]>
*Subject:* Re: [HP-Agilent-Keysight-equipment] HP 54512B (pair)
repair____
__ __
Mike,____
This is unrelated with the issues I'm having with the -12V rail.
When disassembling/reassembling the scope, the EMI Filter (more
specifically, its built-in switch) and the HP arm/button broke
apart. I can now either try to find replacements, or just
replace the EMI Filter with a unit having the switch accessible from
the back of the scope (this type is relatively easy to find) and
disable the actuation of the front button. ____
Radu. ____
__ __
On Mon, Mar 3, 2025 at 8:16?AM Michael Bafaro via groups.io <
groups.io> <m.bafaro@...
<mailto:[email protected]>> wrote:____
Radu,____
____
The pictures you sent appear to be the AC line filter (EMI) and
the power switch and perhaps the line fuse. If one of the
supplies is off and the others are working, then the problem is
somewhere else. ____
____
The display is a standard magnetic deflected CRT. I worked in
that group years ago at Motorola.____
____
Mike Bafaro ____
____
*From:*[email protected] <mailto:HP-
[email protected]> <HP-Agilent-Keysight-
[email protected] <mailto:HP-Agilent-Keysight-
[email protected]>> *On Behalf Of *Radu Bogdan Dicher via
groups.io <>
*Sent:* Sunday, March 2, 2025 7:14 PM
*To:* [email protected] <mailto:HP-
[email protected]>
*Subject:* Re: [HP-Agilent-Keysight-equipment] HP 54512B (pair)
repair____
____
Two steps forward, one step back (one and a half?). ____
____
While other things have been progressing, the power switch
stopped working once I put most of the unit back together. I
enclose some pictures, but it's a typical flip flop type where a
pin prods and finds two different locations between the two
states ON/OFF. I guess I can either look for a replacement (does
anyone have one?), or try to repair it. Repairing something like
this hasn't been something I've had a lot of luck with - if
anyone has some good tips, I'll take them happily - and then
there's also the way the longitudinal arm (actuating the
pressing of the button on the front panel all the way to the
back) is supposed to be handled. It seems to be glued with some
hardened resin or something similar. In retrospect, though the
SM doesn't mention this, I think the arm should be detached
before removing the rear panel and moving it around. It puts too
much pressure and torque on the switch to take this easily and
not get damaged. ____
____
Thank you for any pointers. ____
Radu. ____
____
On Sun, Mar 2, 2025 at 3:20?PM Radu Bogdan Dicher via groups.io
<> <vondicher@...
<mailto:[email protected]>> wrote:____
Razvan,____
Thank you very much, this is very helpful. ____
I've managed to rig a load - I had a couple of 1ohm/10W
Vishay RS10s (bulletproof, in my experience), and it looks
like the -12V rail is MIA because of something going on in
the PS. If I can confirm this, this would be great news (as
opposed to tracking some failed tantalum decoupler or
something else on the main board....). ____
Radu. ____
____
On Sun, Mar 2, 2025 at 2:51?PM Razvan Popescu via groups.io
<> <yo8ryr@...
<mailto:[email protected]>> wrote:____
Hi Radu,
I think the PSU in all 545xx series was made by Boschert
Inc. and
someone already reverse engineered it. I attached the file.
I hope it helps.
Regards,
Razvan
On 02/03/2025 23:33, Radu Bogdan Dicher via groups.io
<> wrote:
> Going back to my -12V rail issue, the SM advises
loading the 5.20V rail
> with a 2ohm/25W resistor. The only way I can put
something similar
> together with what I have at hand is using these
dummy loads I am using
> when repairing audio amplifiers, which are a pair of
8ohm/100W non-
> inductive resistors. By paralleling them I can load
the 5.20V rail with
> a 4ohm resistor.
> What are some thoughts regarding whether this would
be a suitable load
> for the PS? I think the PS just needs a low ohmic
load of sufficient
> dissipation capacity and it should crank itself up to
nominal, but maybe
> there's an aspect I'm overlooking.
> Thank you,
> Radu.
>
> On Sun, Mar 2, 2025 at 1:52?PM Radu Bogdan Dicher via
groups.io <> <
<>> groups.io <>>
<vondicher@...
<mailto:[email protected]> <mailto:[email protected]
<mailto:[email protected]>>>
> wrote:
>
> One of the two scopes is completely disassembled
- head exploding
> emoji - and I have the old battery desoldered
after confirming it's
> fully depleted.
>
> I enclose pics with what I'm using for
replacement. I probably would
> have been fine going with a 2032 type, but the
2430 I ended up
> fitting just right (maybe a bit snug), and the
pins of the holder
> actually match the PCB eyelets. So all is good.
>
> I couldn't figure out what exactly was the
original battery model,
> as it's not legible even after removing the top
tab, but its
> diameter is a bit over 23mm.
> I think this should work OK.
>
> Back to the actual troubleshooting now!
> Radu.
>
> On Fri, Feb 28, 2025 at 6:21?PM Roy J. Tellason,
Sr. via groups.io <>
> < <>>
<roy@...
<mailto:[email protected]>
> <mailto:[email protected]
<mailto:[email protected]>>> wrote:
>
> On Thursday 27 February 2025 04:09:31 pm Radu
Bogdan Dicher via
> groups.io <> <
<>> wrote:
> > One other unfortunate effect of the spot-
welding of the top
> tab is that the
> > battery code is not visible. I can
probably destroy the
> battery once out,
> > and read the CRxyzt battery code, but
would anyone have good
> info offhand
> > on it?
>
> You might find bits of this useful:
>
>
<>
<
<>> en.wikipedia.org/wiki/
List_of_battery_sizes <
List_of_battery_sizes>>
>
> Scroll down to where they discuss coin and
button cells:
>
> "IEC designation numbers indicate the
physical dimensions of the
> cylindrical cell. Cells less than one
centimeter in height are
> assigned four-digit numbers, where the first
two digits are the
> diameter in millimeters, while the last two
digits are the
> height in tenths of millimeters. Taller cells
are assigned five-
> digit numbers, where the first two digits are
the diameter in
> millimeters, followed by the last three
digits indicating the
> height in tenths of millimeters."
>
> So the size of the battery will give you the
info that you need.
>
> --
> 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
>
>
>
>
>
>
____
__
|
Re: E5052A Power On Test (3.3V Bus Supply)
Unlikely to have been from a switching reg -- 1kHz is pretty low. Close-in spurs are often suppressed by some form of cancellation, and a little drift can cause the reappearance of spurs at around that level (or more). That's where I'd look first, anyway. But if it's gone, be happy (unless or until it comes back). :)
Tom
--
Prof. Thomas H. Lee
Allen Ctr., Rm. 205
420 Via Palou Mall
Stanford University
Stanford, CA 94305-4070
toggle quoted message
Show quoted text
On 3/3/2025 1:42 PM, Jim Ford via groups.io wrote: In my case it was a Keysight E8257D PSG that showed spurs >-60 dBc at around 1 kHz offset. ?Our project had about a 6 month lull, and when we got back to the lab and set up the benches again, no such spurs could be found! ?I figured the original spur was from a switching regulator, but who knows?
|
Re: HP 3403C True RMS Voltmeter display fault
Yes, Ed, I know exactly what you mean regarding the orange leadless tantalum caps. ?Sprague used to make them, and they told us that the orange material prevented them from printing the value, voltage, etc on them. ?A real bummer because many times the wrong voltage rating parts were installed and blew up! ?I stopped designing boards with them for that reason. ?Life’s too short to have exploding caps in your products. ?Too short not to intentionally blow them up on the bench, though! ?LOL!??
Jim Ford? Laguna Hills, California, USA?
toggle quoted message
Show quoted text
On Mar 3, 2025, at 10:59?AM, Joel Setton via groups.io <setton@...> wrote:
? Hi AArnaud,
?
Congratulations for the successful repair, and for having saved another valuable HP instrument from the scrap heap !
My conclusion is somewhat identical to my initial thoughts : start by checking the "usual suspects", supply voltages and clocks.
The obvious next step for your 3403C is a complete performance check and recalibration, if you have the appropriate equipment. If you're lucky, first adjusting the calibration in DC-only voltage mode may bring the instrument back into full compliance, which of course would be great news.
After that it'll be time for another instrument repair project, and for more fun !
Cheers,
Joe;
|
Re: E5052A Power On Test (3.3V Bus Supply)
70 MHz Surface Acoustic Wave (SAW) BPFs used to be common for satcom. ?10 kHz is very narrow, though.
I’m snickering a bit at the differences in spur performance in sig gens because I’ve seen exactly that issue before not too long ago. ?In my case it was a Keysight E8257D PSG that showed spurs >-60 dBc at around 1 kHz offset. ?Our project had about a 6 month lull, and when we got back to the lab and set up the benches again, no such spurs could be found! ?I figured the original spur was from a switching regulator, but who knows? ?Either that particular generator had a problem and we have been using a different one since then, or KS fixed that when it went for calibration. ?Cue the Twilight Zone theme!
Jim
toggle quoted message
Show quoted text
On Mar 3, 2025, at 11:46?AM, jmr via groups.io <jmrhzu@...> wrote:
? Hi Jim, thanks. I obtained the cal certificate for the other E5052A today. It was calibrated less than a year ago and this one shows an even lower noise floor.? It's a slightly newer unit and it has some hardware changes although I'm not sure if these changes are the reason it is slightly cleaner than my E5052A. The service manual shows the hardware changes wrt serial number. It also has the same internal spurious frequencies as mine and they appear to be a bit higher in level. It has the backlight spurious at 60 kHz as well.
?
Looking in the service manual, it appears to describe this test at 70 MHz where a (low phase noise) PSG sig gen is used as the signal source at 70 MHz and it is passed through a 10 kHz wide BPF. Presumably some form of crystal filter? This will then shave off all noise down to the thermal level in the stopbands of the filter.
?
I tried this with my E5052A using a lower test frequency (10.7 MHz) and a 15 kHz wide crystal filter and I saw about -175 dBc/Hz at offsets above 1 MHz. Not as good as the newer E5052A but the cal certificate did quote an uncertainty of about +/- 4dB for this test type. I really should do the test at 70 MHz as well. The noise floor may be degraded for carrier frequencies as low as 10.7 MHz.
?
|
Re: HP 54512B (pair) repair
Hi Radu,
If you have a hot air desoldering station try to see if the heat will
soften the glue/resin. Use low temp first and increase it slowly.
Monitor the heat on the arm with an infrared thermometer in the same
time not to melt the arm.
Regards,
Razvan
toggle quoted message
Show quoted text
On 03/03/2025 22:17, Radu Bogdan Dicher via groups.io wrote: Thank you, Mike.
In terms of removing the arm from the switch stub (see pics enclosed a
few messages down), where HP decided to use this brown resin to glue
them together (completely unnecessary, in my opinion - how about a cable
tie or something easy to remove and replace?...), what would be some
recommendations in handling this? Specifically, safely and non-
destructively detaching the arm from the stub. The arm is marked:
"SPREAD JAWS TO INSTALL AND REMOVE," but due to the resin, that was just
about impossible upon my examination when doing this.
* Can anyone determine or have some educated?guess regarding what sort
of glue or resin that'd be? I tried seeing if I could scrape it or
shatter it off, to no avail. It's tough and very hardened in place.
Much?harder than either of the two plastics it joins.
* Solvents? I'd be pretty weary using liquid chemicals over the main
board, but maybe something is recommended and safe to use in a
situation like this.
* What else would?work? I assume others may have had this problem?and
came up with some good solutions.
Thank you,
Radu.
On Mon, Mar 3, 2025 at 8:32?AM Michael Bafaro via groups.io <
groups.io> <m.bafaro@...
<mailto:[email protected]>> wrote:
Radu,____
__ __
I wish you luck finding a replacement for the line filter and
switch.____
__ __
Mike____
__ __
*From:*[email protected] <mailto:HP-Agilent-
[email protected]> <HP-Agilent-Keysight-
[email protected] <mailto:HP-Agilent-Keysight-
[email protected]>> *On Behalf Of *Radu Bogdan Dicher via
groups.io <>
*Sent:* Monday, March 3, 2025 10:23 AM
*To:* [email protected] <mailto:HP-Agilent-
[email protected]>
*Subject:* Re: [HP-Agilent-Keysight-equipment] HP 54512B (pair)
repair____
__ __
Mike,____
This is unrelated with the issues I'm having with the -12V rail.
When disassembling/reassembling the scope, the EMI Filter?(more
specifically, its built-in switch) and the HP arm/button broke
apart. I can now either try to find replacements, or just
replace?the EMI Filter with a unit having the switch accessible from
the back of the scope (this type is relatively easy to find) and
disable the actuation of the front button. ____
Radu. ____
__ __
On Mon, Mar 3, 2025 at 8:16?AM Michael Bafaro via groups.io <
groups.io> <m.bafaro@...
<mailto:[email protected]>> wrote:____
Radu,____
____
The pictures you sent appear to be the AC line filter (EMI) and
the power switch and perhaps the line fuse.? If one of the
supplies is off and the others are working, then the problem is
somewhere else. ____
____
The display is a standard magnetic deflected CRT.? I worked in
that group years ago at Motorola.____
____
Mike Bafaro ____
____
*From:*[email protected] <mailto:HP-
[email protected]> <HP-Agilent-Keysight-
[email protected] <mailto:HP-Agilent-Keysight-
[email protected]>> *On Behalf Of *Radu Bogdan Dicher via
groups.io <>
*Sent:* Sunday, March 2, 2025 7:14 PM
*To:* [email protected] <mailto:HP-
[email protected]>
*Subject:* Re: [HP-Agilent-Keysight-equipment] HP 54512B (pair)
repair____
____
Two steps forward, one step back (one and a half?). ____
____
While other things have been progressing, the power switch
stopped?working once I put?most of the?unit back together. I
enclose some pictures, but it's a typical flip flop type where a
pin prods and finds two different locations between the?two
states ON/OFF. I guess I can either look for a replacement (does
anyone have one?), or try to repair it. Repairing something like
this hasn't been something?I've had a lot of luck with - if
anyone has some good tips, I'll take them happily - and then
there's also the way the longitudinal arm (actuating the
pressing of?the button on the front panel all the way to the
back) is supposed to be handled. It seems to be glued with some
hardened resin or something similar. In retrospect, though the
SM doesn't mention this, I think the arm should be detached
before removing the rear panel and moving it around. It puts too
much pressure?and torque on the switch to take this easily and
not get damaged. ____
____
Thank you for any pointers. ____
Radu. ____
____
On Sun, Mar 2, 2025 at 3:20?PM Radu Bogdan Dicher via groups.io
<> <vondicher@...
<mailto:[email protected]>> wrote:____
Razvan,____
Thank you very much, this is very helpful. ____
I've managed to rig a load - I had a couple of 1ohm/10W
Vishay RS10s (bulletproof, in my experience), and it looks
like the -12V rail is MIA because of something going on in
the PS. If I can confirm?this, this would be great news (as
opposed to tracking some failed tantalum decoupler or
something else on the main board....). ____
Radu. ____
____
On Sun, Mar 2, 2025 at 2:51?PM Razvan Popescu via groups.io
<> <yo8ryr@...
<mailto:[email protected]>> wrote:____
Hi Radu,
I think the PSU in all 545xx series was made by Boschert
Inc. and
someone already reverse engineered it. I attached the file.
I hope it helps.
Regards,
Razvan
On 02/03/2025 23:33, Radu Bogdan Dicher via groups.io
<> wrote:
> Going back to my -12V rail issue, the SM advises
loading the 5.20V rail
> with a 2ohm/25W resistor. The only way I can put
something similar
> together with what I have at hand is using these
dummy loads I am using
> when repairing audio amplifiers, which are a pair of
8ohm/100W non-
> inductive resistors. By paralleling?them I can load
the 5.20V rail with
> a 4ohm resistor.
> What are some thoughts regarding whether this would
be a suitable load
> for the PS? I think the PS just needs a low ohmic
load of sufficient
> dissipation capacity and it should crank itself up to
nominal, but maybe
> there's an aspect I'm overlooking.
> Thank you,
> Radu.
>
> On Sun, Mar 2, 2025 at 1:52?PM Radu Bogdan Dicher via
groups.io <> <
<>> groups.io <>>
<vondicher@...
<mailto:[email protected]> <mailto:[email protected]
<mailto:[email protected]>>>
> wrote:
>
>? ? ?One of the two scopes is completely disassembled
- head exploding
>? ? ?emoji - and I have the old battery desoldered
after confirming?it's
>? ? ?fully depleted.
>
>? ? ?I enclose pics with what I'm using for
replacement. I probably would
>? ? ?have been fine going with a 2032 type, but the
2430 I ended?up
>? ? ?fitting just right (maybe a bit snug), and the
pins of the holder
>? ? ?actually match the PCB eyelets. So all is good.
>
>? ? ?I couldn't figure out what exactly was the
original battery model,
>? ? ?as it's not legible even after removing the top
tab, but its
>? ? ?diameter is a bit over 23mm.
>? ? ?I think this should work OK.
>
>? ? ?Back to the?actual troubleshooting now!
>? ? ?Radu.
>
>? ? ?On Fri, Feb 28, 2025 at 6:21?PM Roy J. Tellason,
Sr. via groups.io <>
>? ? ?< <>>
<roy@...
<mailto:[email protected]>
>? ? ?<mailto:[email protected]
<mailto:[email protected]>>> wrote:
>
>? ? ? ? ?On Thursday 27 February 2025 04:09:31 pm Radu
Bogdan Dicher via
> groups.io <> <
<>> wrote:
>? ? ? ? ? > One other unfortunate effect of the spot-
welding of the top
>? ? ? ? ?tab is that the
>? ? ? ? ? > battery code is not visible. I can
probably destroy the
>? ? ? ? ?battery once out,
>? ? ? ? ? > and read the CRxyzt battery code, but
would anyone have good
>? ? ? ? ?info offhand
>? ? ? ? ? > on it?
>
>? ? ? ? ?You might find bits of this useful:
>
>
<>
<
<>> en.wikipedia.org/wiki/
List_of_battery_sizes <
List_of_battery_sizes>>
>
>? ? ? ? ?Scroll down to where they discuss coin and
button cells:
>
>? ? ? ? ?"IEC designation numbers indicate the
physical dimensions of the
>? ? ? ? ?cylindrical cell. Cells less than one
centimeter in height are
>? ? ? ? ?assigned four-digit numbers, where the first
two digits are the
>? ? ? ? ?diameter in millimeters, while the last two
digits are the
>? ? ? ? ?height in tenths of millimeters. Taller cells
are assigned five-
>? ? ? ? ?digit numbers, where the first two digits are
the diameter in
>? ? ? ? ?millimeters, followed by the last three
digits indicating the
>? ? ? ? ?height in tenths of millimeters."
>
>? ? ? ? ?So the size of the battery will give you the
info that you need.
>
>? ? ? ? ?--
>? ? ? ? ?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
>
>
>
>
>
>
____
__
|
Re: HP 54512B (pair) repair
Thank you, Mike.?
In terms of removing the arm from the switch stub (see pics enclosed a few messages down), where HP decided to use this brown resin to glue them together (completely unnecessary, in my opinion - how about a cable tie or something easy to remove and replace?...), what would be some recommendations in handling this? Specifically, safely and non-destructively detaching the arm from the stub. The arm is marked: "SPREAD JAWS TO INSTALL AND REMOVE," but due to the resin, that was just about impossible upon my examination when doing this.? - Can anyone determine or have some educated?guess regarding what sort of glue or resin that'd be? I tried seeing if I could scrape it or shatter it off, to no avail. It's tough and very hardened in place. Much?harder than either of the two plastics it joins.?
- Solvents? I'd be pretty weary using liquid chemicals over the main board, but maybe something is recommended and safe to use in a situation like this.?
- What else would?work? I assume others may have had this problem?and came up with some good solutions.?
Thank you, Radu.?
On Mon, Mar 3, 2025 at 8:32?AM Michael Bafaro via <m.bafaro= [email protected]> wrote: Radu, ? I wish you luck finding a replacement for the line filter and switch. ? Mike ? ? Mike, This is unrelated with the issues I'm having with the -12V rail. When disassembling/reassembling the scope, the EMI Filter?(more specifically, its built-in switch) and the HP arm/button broke apart. I can now either try to find replacements, or just replace?the EMI Filter with a unit having the switch accessible from the back of the scope (this type is relatively easy to find) and disable the actuation of the front button.? ? On Mon, Mar 3, 2025 at 8:16?AM Michael Bafaro via <m.bafaro=[email protected]> wrote: Radu, ? The pictures you sent appear to be the AC line filter (EMI) and the power switch and perhaps the line fuse.? If one of the supplies is off and the others are working, then the problem is somewhere else.? ? The display is a standard magnetic deflected CRT.? I worked in that group years ago at Motorola. ? Mike Bafaro ? ? Two steps forward, one step back (one and a half?).? While other things have been progressing, the power switch stopped?working once I put?most of the?unit back together. I enclose some pictures, but it's a typical flip flop type where a pin prods and finds two different locations between the?two states ON/OFF. I guess I can either look for a replacement (does anyone have one?), or try to repair it. Repairing something like this hasn't been something?I've had a lot of luck with - if anyone has some good tips, I'll take them happily - and then there's also the way the longitudinal arm (actuating the pressing of?the button on the front panel all the way to the back) is supposed to be handled. It seems to be glued with some hardened resin or something similar. In retrospect, though the SM doesn't mention this, I think the arm should be detached before removing the rear panel and moving it around. It puts too much pressure?and torque on the switch to take this easily and not get damaged.? Thank you for any pointers.? ? On Sun, Mar 2, 2025 at 3:20?PM Radu Bogdan Dicher via <vondicher=[email protected]> wrote: Razvan, Thank you very much, this is very helpful.? I've managed to rig a load - I had a couple of 1ohm/10W Vishay RS10s (bulletproof, in my experience), and it looks like the -12V rail is MIA because of something going on in the PS. If I can confirm?this, this would be great news (as opposed to tracking some failed tantalum decoupler or something else on the main board....).? ? Hi Radu,
I think the PSU in all 545xx series was made by Boschert Inc. and
someone already reverse engineered it. I attached the file.
I hope it helps.
Regards,
Razvan
On 02/03/2025 23:33, Radu Bogdan Dicher via wrote:
> Going back to my -12V rail issue, the SM advises loading the 5.20V rail
> with a 2ohm/25W resistor. The only way I can put something similar
> together with what I have at hand is using these dummy loads I am using
> when repairing audio amplifiers, which are a pair of 8ohm/100W non-
> inductive resistors. By paralleling?them I can load the 5.20V rail with
> a 4ohm resistor.
> What are some thoughts regarding whether this would be a suitable load
> for the PS? I think the PS just needs a low ohmic load of sufficient
> dissipation capacity and it should crank itself up to nominal, but maybe
> there's an aspect I'm overlooking.
> Thank you,
> Radu.
>
> On Sun, Mar 2, 2025 at 1:52?PM Radu Bogdan Dicher via <> > <vondicher=[email protected] <mailto:[email protected]>>
> wrote:
>
>? ? ?One of the two scopes is completely disassembled - head exploding
>? ? ?emoji - and I have the old battery desoldered after confirming?it's
>? ? ?fully depleted.
>
>? ? ?I enclose pics with what I'm using for replacement. I probably would
>? ? ?have been fine going with a 2032 type, but the 2430 I ended?up
>? ? ?fitting just right (maybe a bit snug), and the pins of the holder
>? ? ?actually match the PCB eyelets. So all is good.
>
>? ? ?I couldn't figure out what exactly was the original battery model,
>? ? ?as it's not legible even after removing the top tab, but its
>? ? ?diameter is a bit over 23mm.
>? ? ?I think this should work OK.
>
>? ? ?Back to the?actual troubleshooting now!
>? ? ?Radu.
>
>? ? ?On Fri, Feb 28, 2025 at 6:21?PM Roy J. Tellason, Sr. via
>? ? ?<> <roy=[email protected]
>? ? ?<mailto:[email protected]>> wrote:
>
>? ? ? ? ?On Thursday 27 February 2025 04:09:31 pm Radu Bogdan Dicher via
>? ? ? ? ? <> wrote:
>? ? ? ? ? > One other unfortunate effect of the spot-welding of the top
>? ? ? ? ?tab is that the
>? ? ? ? ? > battery code is not visible. I can probably destroy the
>? ? ? ? ?battery once out,
>? ? ? ? ? > and read the CRxyzt battery code, but would anyone have good
>? ? ? ? ?info offhand
>? ? ? ? ? > on it?
>
>? ? ? ? ?You might find bits of this useful:
>
>? ? ? ? ? <>? ? ? ? ?>
>
>? ? ? ? ?Scroll down to where they discuss coin and button cells:
>
>? ? ? ? ?"IEC designation numbers indicate the physical dimensions of the
>? ? ? ? ?cylindrical cell. Cells less than one centimeter in height are
>? ? ? ? ?assigned four-digit numbers, where the first two digits are the
>? ? ? ? ?diameter in millimeters, while the last two digits are the
>? ? ? ? ?height in tenths of millimeters. Taller cells are assigned five-
>? ? ? ? ?digit numbers, where the first two digits are the diameter in
>? ? ? ? ?millimeters, followed by the last three digits indicating the
>? ? ? ? ?height in tenths of millimeters."
>
>? ? ? ? ?So the size of the battery will give you the info that you need.
>
>? ? ? ? ?--
>? ? ? ? ?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
>
>
>
>
>
>
|
Re: HP8510C TRL Calibration
I put an 8510C driver into scikit-rf the other year that speaks the binary format and knows how to stitch sweeps, so if not it should be a quick code change especially if you already have PyVISA and scikit-rf in your codebase:
?
?
|
Re: E5052A Power On Test (3.3V Bus Supply)
Hi Jim, thanks. I obtained the cal certificate for the other E5052A today. It was calibrated less than a year ago and this one shows an even lower noise floor.? It's a slightly newer unit and it has some hardware changes although I'm not sure if these changes are the reason it is slightly cleaner than my E5052A. The service manual shows the hardware changes wrt serial number. It also has the same internal spurious frequencies as mine and they appear to be a bit higher in level. It has the backlight spurious at 60 kHz as well.
?
Looking in the service manual, it appears to describe this test at 70 MHz where a (low phase noise) PSG sig gen is used as the signal source at 70 MHz and it is passed through a 10 kHz wide BPF. Presumably some form of crystal filter? This will then shave off all noise down to the thermal level in the stopbands of the filter.
?
I tried this with my E5052A using a lower test frequency (10.7 MHz) and a 15 kHz wide crystal filter and I saw about -175 dBc/Hz at offsets above 1 MHz. Not as good as the newer E5052A but the cal certificate did quote an uncertainty of about +/- 4dB for this test type. I really should do the test at 70 MHz as well. The noise floor may be degraded for carrier frequencies as low as 10.7 MHz.
?
|
Re: HP 3403C True RMS Voltmeter display fault
Hi AArnaud,
?
Congratulations for the successful repair, and for having saved another valuable HP instrument from the scrap heap !
My conclusion is somewhat identical to my initial thoughts : start by checking the "usual suspects", supply voltages and clocks.
The obvious next step for your 3403C is a complete performance check and recalibration, if you have the appropriate equipment. If you're lucky, first adjusting the calibration in DC-only voltage mode may bring the instrument back into full compliance, which of course would be great news.
After that it'll be time for another instrument repair project, and for more fun !
Cheers,
Joe;
|
Re: HP 3403C True RMS Voltmeter display fault
I recently had one destroy itself on an HP 16717a logic blade. Burned all of the
way through the pcb, great fun. I guess that was early 90s vintage.
Paul
toggle quoted message
Show quoted text
On Mon, Mar 03, 2025 at 09:55:33AM -0800, ed breya wrote: I forgot to comment on hermetic solid Ta caps. I have seen only a few failures of these over the years, and I consider them among the best of parts for reliability. I have seen lots and lots of failures in all kinds of non-hermetic Ta caps, especially certain brands of dipped style. My experience here is with the older parts in the same vintage as most of my gear and such, so not so much about more modern parts which should be better. For instance, I have seen very few failures in surface mount style solid Ta types that are so common now. These are non-hermetic but seem to survive OK. Or, maybe after these rack up many years they may degrade like the others. Only time will tell.
Ed
--
Paul Amaranth, GCIH | Manchester MI, USA
Aurora Group of Michigan, LLC | Security, Systems & Software
paul@... | Linux/Unix - We don't do windows
|
Re: HP 3403C True RMS Voltmeter display fault
I know what you mean Dave. I've seen soldery-looking stuff on some blown dipped Ta caps - the ones that haven't been burnt to a crisp. There is some solder in those too I think, for connection to the outside surface of the slug. As I recall, the Ta oxide slug is sintered around the steel anode lead and directly bonded, while the outside of the slug is coated or plated with solder or some equivalent alloy that can connect to the steel cathode lead, then all dipped in an epoxy.
?
I think SMT ones have some solder on each end of the slug for connection to the lead/pad structures, and have the cap element structure and polarizing features worked out somehow internally.
?
I have some rather odd "leadless" SMT style solid Ta caps with interesting structure. These are orange colored with a thin coating, and no plastic encapsulation, and go directly in-circuit via the solder-tinned ends. One end has a short wire stub poking out, which is the internal anode connection and polarity marker. There's no marking at all on the bodies, so takes some guesswork to figure out. I found datasheets years ago so I could figure out the ratings by part size and measured C. I keep these for ultra-low R and L uses.
?
Ed
|
Re: HP8510C TRL Calibration
Out of curiosity, did you have any speed optimization enabled on your IEEE-488 interface?
?
What software version was your 8510C running?
|
Re: HP8510C CalKit file .CK_ format
Hi Calvin,
Here is what I use for my HP8753D and 8720C, Basically I'm using GPIB to define a new calkit on the unit, then I download and save the binary blob as is. That binary blob can later be uploaded as is. It ought to be fairly easy to convert this to C.
Br Marcus
On Sun, Mar 2, 2025 at 11:58?PM Calvin Guan via <guancalvin= [email protected]> wrote: Hi there,
?
I'm trying to generate the calkit file CK_ programmatically instead of punching them in various GUI based CalKit manager.
?
Basically, I'm doing my homemade open and slot standards and characterize them to use as poor man's Calkit for non-critical measurement to reduce the wear and tear on my expensive Cal Kit.
?
Manually entering the polynomials and class assignments in the VNA CalKit manager is very slow and painful. I'm trying to generate it a C program so that I can send it to my 8510 either by GPIB or floppy disk but I can't find the format of the 8510 CK_ file.
?
Does anyone know?
?
Regards,
Calvin
|
Re: HP 3403C True RMS Voltmeter display fault
On 3/2/25 19:05, AArnaud via groups.io wrote: The other one ooks just as weird but is healthy according to the chinese component tester.
Are there guidelines on HP capacitor replacements? Such as caps that never/very rarely fail and those who absolutely always do?
I want to recap this unit to keep it. It's not calibrated anymore of course but it's so great. Quality long life capacitor are expensive, I don't want to replace what does not need to be. I usually "replace like with like", or at least a modern equivalent. You should see all the problems that come up with people with no electronics knowledge on the vintage computing mailing lists going off the deep end with the "recapping" craze, thinking it will cure all ills...frequently they replace electrolytics with high-K ceramic capacitors and wonder why their power supply rails don't work. ;) -Dave -- Dave McGuire, AK4HZ New Kensington, PA
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Re: HP 3403C True RMS Voltmeter display fault
On 3/3/25 12:41, ed breya wrote: That's an interesting picture of the failed cap. I'd guess the molten blob on the can end is just some electrical solder that ended up there by coincidence sometime in the past, or maybe from inside the part. Try hitting it with a soldering iron - it should melt. If it doesn't, then I guess it could be Ta.
Metallic tantalum does not normally look like that, all silvery and shiny, because oxides form on the surface with a range of iridescent colors. It's more of a refractory metal that would not exist molten at a temperature that wouldn't have turned the rest of the part to ash. Besides that, the "solid" Ta caps are mostly Ta oxides and very little metal, sintered into solid slugs, and I can't picture there being that much actual Ta metal present (in proportion) inside a cap of that size. There could have been that much electrical solder in there though. It's used to make internal contacts, and especially to solder the electrical leads and glass/metal hermetic sealing disc into the can. Ordinarily I would agree, but I've seen this "blob of metal on the side of a dipped Ta capacitor" failure many times, and it's always shiny and looks a lot like solder. -Dave -- Dave McGuire, AK4HZ New Kensington, PA
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Re: HP 3403C True RMS Voltmeter display fault
I forgot to comment on hermetic solid Ta caps. I have seen only a few failures of these over the years, and I consider them among the best of parts for reliability. I have seen lots and lots of failures in all kinds of non-hermetic Ta caps, especially certain brands of dipped style. My experience here is with the older parts in the same vintage as most of my gear and such, so not so much about more modern parts which should be better. For instance, I have seen very few failures in surface mount style solid Ta types that are so common now. These are non-hermetic but seem to survive OK. Or, maybe after these rack up many years they may degrade like the others. Only time will tell.
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Ed
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Dave McGuire