Re: HP 400E sticky needle
I have a dozen of these meters (mostly power meters) rescued from scrap, about half of them have the faceplate going in flakes, one or two badly.
I've heard about a mysterious "Krylon" (that I don't have), about Milk (that I have), and about a method with the Pritt stick (that I have, too).
What else?
How exactly did you do it with the Pritt-Stick method?
What is Krylon? Is there something similar I can find in EU / Germany?
I'm tempted to try the milk thing... what is the best way to proceed - spraying it on the faceplate and let it sit in?
I've repaired such a faceplate once many years ago and do not remember anymore how. I must have scanned it, and printed it somehow. I sold it, so I cannot check.
cheers
Martin
|
Re: HP 400E sticky needle
?I saved this one from the scrap heap. The face plate was pretty bad, I came out better than I thought it would. I just flaked off the parts that I new I couldn't save. One it cracked it started to curl so I just broke off what was loose, if it was going towards a number or line I used my exacto knife to cut it so as to not lose anything important. Then I just put clear Krylon over it to hopefully hold everything in place. Some of the face plate curled up so high the needle could not move past it. 
|
Re: HP 400E sticky needle
Ok victory announced. The display remains stuck down after 24 hours which is good. The sticky was sorted by very carefully blowing the movement out with an air duster and then working around the armature and 0 and full deflection with an anti static brush. Works fine now. Thanks for the suggestions everyone :) 
|
|
|
|
|
Re: Looking for Agilent PNA old FW repo?
Hello,
For 8357A the latest version was A.06.04.32 (PNA_A060432.msi released Aug 2007) if it has the 500MHz CPU and Windows XP.
If it has the 266MHz CPU and Windows 2000 the latest version released was A.04.87.01 (PNA_A048701.msi released Sep 2005).
I am also looking for these files but they are nowhere to be found...
Regards,
Razvan
|
Calibration HP 54720D (make 54717A )
Hello, I will share new knowledge :)
Calibration values 54720D were lost after the battery died.?
Can be calibrated using any of the modules for the 54750A/83480A.
Successfully calibrated using board from 83483A.
Set the dip switch 83483A to 17, (54717A)?
?
I took out control board from the 83483A and inserted it into the 54713B module. I removed the N connector. I connected the rear outputs (bottom) trigger and (top) channel through the smb to sma reduction from the hole in the front panel. You don't need to use the limiter, it's there for protection. I marked the cables. The module must be inserted into each slot and each channel + trigger calibrated. Insert the module, start the calibration and follow the instructions on the display.
A 20db attenuator, tee, and 50ohm termination will be needed.
I then restored the 54713B to its original state, the module was modified temporarily for calibration. The procedure works and will restore glory to your unit.
It's sad that HP didn't think of a backup of the calibration values on diskettes, it would have been nice.
Should work with all modules for 54750A/83480A as long as they have a switch. The downside is that these modules cost quite a bit of money.   
?
more photos in the attachment...
?
|
Radu -
Entirely possible, but I have (surprisingly) seen few serious problems cluse by power supply failure in HP instruments. Some but not many.
I would still take a look at the no DELTA_F problem first. Kinda speaks to a VCO problem or at least a VCO not changing frequency due to some control problem. Next best guess is a mixer malfunction (but I think this is less likely).
I would try to find out where the ~ 21 MHz signal is coming from and then see what controls that source. A likely culpert is a "stuck" VCO - and the problem becomes WHY is it stuck. A problematic VCO PLL / PLL detector seams a likely candidate.
Keep on having fun :-)
Cheers!
Bruce
Quoting Radu Bogdan Dicher <vondicher@...>:
toggle quoted message
Show quoted text
Bruce,
I think there are two independent issues (still) going on at the same time.
So my initial gut feeling there may be one single trouble point triggering
this eclectic set of fails we're looking at currently was probably overly
optimistic. At least as far as I can tell right now.
I wonder if the power supply event took a bunch of things offline with it.
It's the only way I can figure what seems to be two outstanding issues left
on the docket after fixing one.
Radu.
On Sun, Sep 18, 2022 at 7:24 PM Bruce <bruce@...> wrote:
I was going to point that out.
If it was the filters, the frequency would vary. The output might
drop off, particularly if no filter ws properly selected outside the
range where you see output.
I think the main symptom is that the frequency does not vary. Check
the VCO output for frequency variation, if the VCOs seem to vayr, then
I'd look at the inputs to the mixers.
Cheers!
Bruce
Quoting Radu Bogdan Dicher <vondicher@...>:
...which doesn't explain the output stuck at 21.5MHz, but at least may
point out what's going on as far as the missing output outside of 14 - <
20MHz range
Radu.
On Sun, Sep 18, 2022 at 6:44 PM Radu Bogdan Dicher via groups.io <vondicher=
[email protected]> wrote:
I was just starting to focus on that, Ozan, as soon as I started perusing
Service Group L, as per your earlier point here. Thanks a ton for
narrowing
down the scope of the forensics.
To check the validity of this notion, I double-checked specifically the
19-20MHz to see if I see output (a bit of a blind spot in my earlier
measurements), and what do you know... Smoking gun! There's output all
the
way to instrument limit on 19.(9)MHz.
The filtering and associated servos seem to be the culprit here.
Radu.
On Sun, Sep 18, 2022 at 5:26 PM Ozan <ozan_g@...> wrote:
It turns out dividers are followed by a bank of filters. 14MHz to
<20MHz
(exact point is not marked) is one of the filters. It is possible
control
signals to the filter bank is not functioning. TP1 on the schematic is
just
before the filter banks. If it is accessible and you could observe
TP1, it
may help debug.
Ozan
On Sun, Sep 18, 2022 at 03:29 PM, Ozan wrote:
On Sun, Sep 18, 2022 at 10:59 AM, Radu Bogdan Dicher wrote:
I got some really weird data to report.
I've been playing with adjusting the levels and frequency.
1. It seems I am able to get an output between exactly 14MHz and
19MHz. One half a MHz up or down from there, output drops to zero.
2. As long as there's output (as above), the level adjustment seems
to be working OK. I haven't looked closer at whether the value
is exactly
what it should be, but it raises and lowers as I command it from the
AMPLITUDE controls.
3. The frequency doesn't change as I adjust per #1 above. It's
always
about 21.5MHz (says my scope).
Not sure what to make of it yet, but I am going to seek to determine
whether this can be triggered by a single module, pull it out and look
for
damaged caps (first line of defense).
Thank you all.
Radu.
---
Hi Radu,
Bruce's reply is the right way to debug. Looking at service manual,
over
the band of 10MHz-20MHz signal path through dividers look same so
output
going away just below 14MHz could be something with VCO loop. Output
staying at 21.5MHz, not changing is also pointing to the VCO/PLL. I
would
look at signal coming to J-2 of A2 "divider filter" in Fig 8-L-1.
Whether
it changes and whether it goes away below 14MHz setting.
Do you see any signal out at 2x this frequency, i.e. 28MHz-38MHz range?
Ozan
|
Bruce, I think there are two independent issues (still) going on at the same time. So my initial gut feeling there may be one single trouble point triggering this eclectic set of fails we're looking at currently was probably overly optimistic. At least as far as I can tell right now.? I wonder if the power supply event took a bunch of things offline with it. It's the only way I can figure what seems to be two outstanding issues left on the docket after fixing one.? Radu.?
On Sun, Sep 18, 2022 at 7:24 PM Bruce < bruce@...> wrote: I was going to point that out.
If it was the filters, the frequency would vary.? The output might?
drop off, particularly if no filter ws properly selected outside the?
range where you see output.
I think the main symptom is that the frequency does not vary.? Check?
the VCO output for frequency variation, if the VCOs seem to vayr, then?
I'd look at the inputs to the mixers.
Cheers!
Bruce
Quoting Radu Bogdan Dicher <vondicher@...>:
> ...which doesn't explain the output stuck at 21.5MHz, but at least may
> point out what's going on as far as the missing output outside of 14 - <
> 20MHz range
> Radu.
>
> On Sun, Sep 18, 2022 at 6:44 PM Radu Bogdan Dicher via <vondicher=
> [email protected]> wrote:
>
>> I was just starting to focus on that, Ozan, as soon as I started perusing
>> Service Group L, as per your earlier point here. Thanks a ton for narrowing
>> down the scope of the forensics.
>>
>> To check the validity of this notion, I double-checked specifically the
>> 19-20MHz to see if I see output (a bit of a blind spot in my earlier
>> measurements), and what do you know... Smoking gun! There's output all the
>> way to instrument limit on 19.(9)MHz.
>>
>> The filtering and associated servos seem to be the culprit here.
>> Radu.
>>
>> On Sun, Sep 18, 2022 at 5:26 PM Ozan <ozan_g@...> wrote:
>>
>>> It turns out dividers are followed by a bank of filters. 14MHz to <20MHz
>>> (exact point is not marked) is one of the filters. It is possible control
>>> signals to the filter bank is not functioning. TP1 on the schematic is just
>>> before the filter banks. If it is accessible and you could observe TP1, it
>>> may help debug.
>>>
>>> Ozan
>>>
>>>
>>> On Sun, Sep 18, 2022 at 03:29 PM, Ozan wrote:
>>>
>>> On Sun, Sep 18, 2022 at 10:59 AM, Radu Bogdan Dicher wrote:
>>>
>>> I got some really weird data to report.
>>>
>>> I've been playing with adjusting the levels and frequency.
>>>
>>>? ? 1. It seems I am able to get an output between exactly 14MHz and
>>>? ? 19MHz. One half a MHz up or down from there, output drops to zero.
>>>? ? 2. As long as there's output (as above), the level adjustment seems
>>>? ? to be working OK. I haven't looked closer at whether the value?
>>> is exactly
>>>? ? what it should be, but it raises and lowers as I command it from the
>>>? ? AMPLITUDE controls.
>>>? ? 3. The frequency doesn't change as I adjust per #1 above. It's always
>>>? ? about 21.5MHz (says my scope).
>>>
>>> Not sure what to make of it yet, but I am going to seek to determine
>>> whether this can be triggered by a single module, pull it out and look for
>>> damaged caps (first line of defense).
>>>
>>> Thank you all.
>>> Radu.
>>>
>>> ---
>>> Hi Radu,
>>> Bruce's reply is the right way to debug. Looking at service manual, over
>>> the band of 10MHz-20MHz signal path through dividers look same so output
>>> going away just below 14MHz could be something with VCO loop. Output
>>> staying at 21.5MHz, not changing is also pointing to the VCO/PLL. I would
>>> look at signal coming to J-2 of A2 "divider filter" in Fig 8-L-1.? Whether
>>> it changes and whether it goes away below 14MHz setting.
>>>
>>> Do you see any signal out at 2x this frequency, i.e. 28MHz-38MHz range?
>>>
>>> Ozan
>>>
>>>
>>>
>>
>>
>
>
>
|
I was going to point that out.
If it was the filters, the frequency would vary. The output might drop off, particularly if no filter ws properly selected outside the range where you see output.
I think the main symptom is that the frequency does not vary. Check the VCO output for frequency variation, if the VCOs seem to vayr, then I'd look at the inputs to the mixers.
Cheers!
Bruce
Quoting Radu Bogdan Dicher <vondicher@...>:
toggle quoted message
Show quoted text
...which doesn't explain the output stuck at 21.5MHz, but at least may
point out what's going on as far as the missing output outside of 14 - <
20MHz range
Radu.
On Sun, Sep 18, 2022 at 6:44 PM Radu Bogdan Dicher via groups.io <vondicher=
[email protected]> wrote:
I was just starting to focus on that, Ozan, as soon as I started perusing
Service Group L, as per your earlier point here. Thanks a ton for narrowing
down the scope of the forensics.
To check the validity of this notion, I double-checked specifically the
19-20MHz to see if I see output (a bit of a blind spot in my earlier
measurements), and what do you know... Smoking gun! There's output all the
way to instrument limit on 19.(9)MHz.
The filtering and associated servos seem to be the culprit here.
Radu.
On Sun, Sep 18, 2022 at 5:26 PM Ozan <ozan_g@...> wrote:
It turns out dividers are followed by a bank of filters. 14MHz to <20MHz
(exact point is not marked) is one of the filters. It is possible control
signals to the filter bank is not functioning. TP1 on the schematic is just
before the filter banks. If it is accessible and you could observe TP1, it
may help debug.
Ozan
On Sun, Sep 18, 2022 at 03:29 PM, Ozan wrote:
On Sun, Sep 18, 2022 at 10:59 AM, Radu Bogdan Dicher wrote:
I got some really weird data to report.
I've been playing with adjusting the levels and frequency.
1. It seems I am able to get an output between exactly 14MHz and
19MHz. One half a MHz up or down from there, output drops to zero.
2. As long as there's output (as above), the level adjustment seems
to be working OK. I haven't looked closer at whether the value is exactly
what it should be, but it raises and lowers as I command it from the
AMPLITUDE controls.
3. The frequency doesn't change as I adjust per #1 above. It's always
about 21.5MHz (says my scope).
Not sure what to make of it yet, but I am going to seek to determine
whether this can be triggered by a single module, pull it out and look for
damaged caps (first line of defense).
Thank you all.
Radu.
---
Hi Radu,
Bruce's reply is the right way to debug. Looking at service manual, over
the band of 10MHz-20MHz signal path through dividers look same so output
going away just below 14MHz could be something with VCO loop. Output
staying at 21.5MHz, not changing is also pointing to the VCO/PLL. I would
look at signal coming to J-2 of A2 "divider filter" in Fig 8-L-1. Whether
it changes and whether it goes away below 14MHz setting.
Do you see any signal out at 2x this frequency, i.e. 28MHz-38MHz range?
Ozan
|
54502A toasted attenuator replacement
Hello all, I'm helping a friend of mine, an ECE student at a local university, repair some equipment he recently got out of a lab's junk pile. Arguably the best bit of kit out of the whole stack is a 54502A, but it has some problems with the inputs. Channel 2's input attenuator seems to get stuck at either 50 or 1M ohm, and is shorted. Maybe something as simple as bad relays? Channel 1 is completely toasted.
Does anyone have any recommendations on where we can get our hands on replacement attenuators? The unit passes all self tests otherwise and seems to be in great physical shape.
Thanks! John KC1QLN
|
...which doesn't explain the output stuck at 21.5MHz, but at least may point out what's going on as far as the missing output outside of 14 - < 20MHz range Radu.?
On Sun, Sep 18, 2022 at 6:44 PM Radu Bogdan Dicher via <vondicher= [email protected]> wrote: I was just starting to focus on that, Ozan, as soon as I started?perusing Service Group L, as per your earlier point here. Thanks a ton for narrowing down the scope of the forensics.?
To check the validity of this notion, I double-checked specifically the 19-20MHz to see if I see output?(a bit of a blind spot in my earlier measurements), and what do you know... Smoking gun! There's output all the way to instrument limit on 19.(9)MHz.?
The filtering and associated servos seem to be the culprit?here.? Radu.?
On Sun, Sep 18, 2022 at 5:26 PM Ozan < ozan_g@...> wrote: It turns out dividers are followed by a bank of filters. 14MHz to <20MHz (exact point is not marked) is one of the filters. It is possible control signals to the filter bank is not functioning. TP1 on the schematic is just before the filter banks. If it is accessible and you could observe TP1, it may help debug.
Ozan
On Sun, Sep 18, 2022 at 03:29 PM, Ozan wrote:
On Sun, Sep 18, 2022 at 10:59 AM, Radu Bogdan Dicher wrote:
I got some really weird data to report.?
?
I've been playing with adjusting the levels and frequency.?
- It seems I am able to get an output between exactly 14MHz and 19MHz. One half a MHz up or down from there, output drops to zero.?
- As long as there's output (as above), the level adjustment seems to be working OK. I haven't looked closer at whether the value is exactly what it should be, but it raises and lowers as I command it from the AMPLITUDE controls.?
- The frequency doesn't change as I adjust per #1 above. It's always about 21.5MHz (says my scope).?
Not sure what to make?of it yet, but I am going to seek to determine whether this can be triggered by a single module, pull it out and look for damaged caps (first line of defense).
?
Thank you all.?
Radu.?
---
Hi Radu,
Bruce's reply is the right way to debug. Looking at service manual, over the band of 10MHz-20MHz signal path through dividers look same so output going away just below 14MHz could be something with VCO loop. Output staying at 21.5MHz, not changing is also pointing to the VCO/PLL. I would look at signal coming to J-2 of A2 "divider filter" in Fig 8-L-1.? Whether it changes and whether it goes away below 14MHz setting.
Do you see any signal out at 2x this frequency, i.e. 28MHz-38MHz range?
Ozan
|
I was just starting to focus on that, Ozan, as soon as I started?perusing Service Group L, as per your earlier point here. Thanks a ton for narrowing down the scope of the forensics.?
To check the validity of this notion, I double-checked specifically the 19-20MHz to see if I see output?(a bit of a blind spot in my earlier measurements), and what do you know... Smoking gun! There's output all the way to instrument limit on 19.(9)MHz.?
The filtering and associated servos seem to be the culprit?here.? Radu.?
On Sun, Sep 18, 2022 at 5:26 PM Ozan < ozan_g@...> wrote: It turns out dividers are followed by a bank of filters. 14MHz to <20MHz (exact point is not marked) is one of the filters. It is possible control signals to the filter bank is not functioning. TP1 on the schematic is just before the filter banks. If it is accessible and you could observe TP1, it may help debug.
Ozan
On Sun, Sep 18, 2022 at 03:29 PM, Ozan wrote:
On Sun, Sep 18, 2022 at 10:59 AM, Radu Bogdan Dicher wrote:
I got some really weird data to report.?
?
I've been playing with adjusting the levels and frequency.?
- It seems I am able to get an output between exactly 14MHz and 19MHz. One half a MHz up or down from there, output drops to zero.?
- As long as there's output (as above), the level adjustment seems to be working OK. I haven't looked closer at whether the value is exactly what it should be, but it raises and lowers as I command it from the AMPLITUDE controls.?
- The frequency doesn't change as I adjust per #1 above. It's always about 21.5MHz (says my scope).?
Not sure what to make?of it yet, but I am going to seek to determine whether this can be triggered by a single module, pull it out and look for damaged caps (first line of defense).
?
Thank you all.?
Radu.?
---
Hi Radu,
Bruce's reply is the right way to debug. Looking at service manual, over the band of 10MHz-20MHz signal path through dividers look same so output going away just below 14MHz could be something with VCO loop. Output staying at 21.5MHz, not changing is also pointing to the VCO/PLL. I would look at signal coming to J-2 of A2 "divider filter" in Fig 8-L-1.? Whether it changes and whether it goes away below 14MHz setting.
Do you see any signal out at 2x this frequency, i.e. 28MHz-38MHz range?
Ozan
|
Re: Pozidrive screws on HP covers
Reed and Prince are different from
Pozidrive.
There are a lot of cross point screw heads.
I was introduced to JIS and JCIS screws by Maryland Metrics while
working on cameras at a TV station.
There are used extensively in cameras.
The tools that I used were made by Moody and they do stand behind
their tools.
I broke the tip on two JIS drivers and Moody replaced them with
just a phone call.
Glenn
On 9/17/2022 10:38 PM, Mike D. wrote:
Back in the '60's, while In the USAF, we knew these as "Reed
and Prince" screw heads.? I've since noted the more commonly
used term of Pozidriv's.? .
--
-----------------------------------------------------------------------
Glenn Little ARRL Technical Specialist QCWA LM 28417
Amateur Callsign: WB4UIV wb4uiv@... AMSAT LM 2178
QTH: Goose Creek, SC USA (EM92xx) USSVI, FRA, NRA-LM ARRL TAPR
"It is not the class of license that the Amateur holds but the class
of the Amateur that holds the license"
|
It turns out dividers are followed by a bank of filters. 14MHz to <20MHz (exact point is not marked) is one of the filters. It is possible control signals to the filter bank is not functioning. TP1 on the schematic is just before the filter banks. If it is accessible and you could observe TP1, it may help debug.
Ozan
toggle quoted message
Show quoted text
On Sun, Sep 18, 2022 at 03:29 PM, Ozan wrote:
On Sun, Sep 18, 2022 at 10:59 AM, Radu Bogdan Dicher wrote:
I got some really weird data to report.?
?
I've been playing with adjusting the levels and frequency.?
- It seems I am able to get an output between exactly 14MHz and 19MHz. One half a MHz up or down from there, output drops to zero.?
- As long as there's output (as above), the level adjustment seems to be working OK. I haven't looked closer at whether the value is exactly what it should be, but it raises and lowers as I command it from the AMPLITUDE controls.?
- The frequency doesn't change as I adjust per #1 above. It's always about 21.5MHz (says my scope).?
Not sure what to make?of it yet, but I am going to seek to determine whether this can be triggered by a single module, pull it out and look for damaged caps (first line of defense).
?
Thank you all.?
Radu.?
---
Hi Radu,
Bruce's reply is the right way to debug. Looking at service manual, over the band of 10MHz-20MHz signal path through dividers look same so output going away just below 14MHz could be something with VCO loop. Output staying at 21.5MHz, not changing is also pointing to the VCO/PLL. I would look at signal coming to J-2 of A2 "divider filter" in Fig 8-L-1. ?Whether it changes and whether it goes away below 14MHz setting.
Do you see any signal out at 2x this frequency, i.e. 28MHz-38MHz range?
Ozan
|
Re: Pozidriv screws on HP covers
Introduced in 1967 but patented until around 1990. Once the patent is in the public domain, HP (and every other user) no longer has to pay to use it.
|
Re: Source of floppy disks
I recently grabbed a bunch of new old stock 3.5" disks at Goodwill. Also an imation D353FUE USB style 3.5" drive works well with WinXP and WIN10.. I am told that HP laptop external drives work well. The Chinese knock offs on Amazon are junk.? I still maintain a IBM PS/2E pizza box for Motorola radio programming.
|
On Sun, Sep 18, 2022 at 10:59 AM, Radu Bogdan Dicher wrote:
I got some really weird data to report.?
?
I've been playing with adjusting the levels and frequency.?
- It seems I am able to get an output between exactly 14MHz and 19MHz. One half a MHz up or down from there, output drops to zero.?
- As long as there's output (as above), the level adjustment seems to be working OK. I haven't looked closer at whether the value is exactly what it should be, but it raises and lowers as I command it from the AMPLITUDE controls.?
- The frequency doesn't change as I adjust per #1 above. It's always about 21.5MHz (says my scope).?
Not sure what to make?of it yet, but I am going to seek to determine whether this can be triggered by a single module, pull it out and look for damaged caps (first line of defense).
?
Thank you all.?
Radu.?
--- Hi Radu, Bruce's reply is the right way to debug. Looking at service manual, over the band of 10MHz-20MHz signal path through dividers look same so output going away just below 14MHz could be something with VCO loop. Output staying at 21.5MHz, not changing is also pointing to the VCO/PLL. I would look at signal coming to J-2 of A2 "divider filter" in Fig 8-L-1. ?Whether it changes and whether it goes away below 14MHz setting. Do you see any signal out at 2x this frequency, i.e. 28MHz-38MHz range? Ozan
|
Bruce reminded me of a funny one I ran into. Not on a 3335 a 3330. The ribbon control cable was failing and sending messed up bits. Changed the cable and all was fine. It was actually hard to figure out it was the cable. Good luck. Paul WB8TSL
|
Re: A tale of 2 8640B sig gens
The all synthesized Hp8642A was supposed to be a suitable replacement of the Hp8640B in terms of performance. It was a monster, heavy and built with a series of cast cavities that held many of the circuit boards. Cooling was the downfalling of the thing, as the infamous rotting foam was used on the bottom cover, in various places to route air through the cavities via small vent holes. I bought one from Tucker at work, in the 1990s as many of our 8640s had the mechanical issues by then. When we fired it up it gave temperature errors. We were satisfied with theHp8657B at the time since we weren't doing receiver testing. I never did stomach fixing that 8642 nor make workbench space (it is a deep unit).
|
Martin
RFI-EMI-GUY