Looking for photos and Dimensions of U1880A Deskew Fixture
Hi all,
I have a few current probes in my collection and I'm now looking at getting a probe deskew fixture.
I want to replicate the Tek 067-1686-00, but with some 555 timers to make it self contained like the Agilent/Keysight U1880A
Does anyone here have one of these that they can scan or take good photos and measure the dimensions?
There is a photo in the user manual but it's not quite high enough resolution to see many markings (and there's no picture of the rear side)
I'll be open-sourcing my design for others to use once I have it completed.
Thanks!
Jared
|
Adri, Here for information, is the DANL and flatness test that I did, at the end of April 2024, after the YTF change and recalibration. When you have completed everything, you should have similar results. ? Yves ? hello Yves,
I received the 2nd converter and, after testing it on the bench (if you are interested I will give you the two test configurations) I installed it and voil¨¤, the machine is back to working like in the old days
It passes the amplitude and frequency calibrations and the confidence test without any problem
As it happened before the death of the YTO the analyzer still has a certain "deafness" after 5.5GHz
By virtue of the alignment of the spheres that I did a few weeks ago The defect is milder than it was then and I think it is due to a sub-optimal loss of insertion of the SYTF A3A2 As proof of the "deafness", while all the calibration routines, including the CAL YTF routine are performed without problems, the CAL MXR is not completed and gives the message CAL: HARMONICS INSUFFICIENT In fact I attach a screen of the 300MHz calibration signal from which it would seem that the very last harmonics are missing
Thank you in advance if can you send the analogous screen of your analyzer
In a few days I will receive a more reliable 6GHz RF generator than the current one and I will use it to try to perfect the alignment
Yves, I think that now you can reassemble and close your analyzer :-) Many thanks for all the measurements that you sent me and that were useful to trace the problem!
Adri
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----- Messaggio originale ----- Inviato: 08/09/2024 01:35:49 Oggetto: Re: [HP-Agilent-Keysight-equipment] HP 5086-7906 YTO
Hi Adri ? Here are the measurements connected to the first 2 converters as a reference. ? For the second converter I get a voltage of -1.678V instead of -3.5V as written in the service manual, I would say that we have similar voltages for this particular point. It seems far from the nominal point, but there may be an error in the manual. ? You are close to the goal, and this module may be repairable if there is no micro circuit, I have never opened a second converter in this series, but it is a possibility. ? When you open your second converter, send me pictures, I'm curious. ? Yves ? dear Yves, I didn't realize that you had made the measurements expressly to help me! I owe you then a double (even triple) thanks! Especially considering the fact that the front end of this instrument is really very dense, complicated and delicate! After my last email, in addition to doing the (essentially mechanical) intervention on the SYTF, I continued to check the input signal through the various sections by alternately injecting 300MHz @-20dBm and 5GHz @0 dBm The signals were found to be in specification up to the A3A9 bandpass (where the two paths join to form the intermediate frequency of 321.4MHz). At this point I could see the 5GHz signal (converted), present at that point at -47dBm (the specification says -43/-56dBm).
Instead, no trace of the 300MHz input signal
Investigatine?the second converter A3A4 in more depth
I checked?the signals at its input
On J1 there is 3.9214GHz at -46dBm? --->OK
On J3 there is 321.4MHz @ -37.7dBm? --->OK
On J4 I did not check 600MHz @-1dBm but the fact that the converter works in band 1 tells me that the oscillator is present and is in specification
The power supply is quite OK (5V are actually 4.75; 10V are 9.98 and the DC that controls the internal switch that should be +15V? (band 0) and -3.5V?(band 1) is actually +14.60V and -1.35V
This last value is rather far from the nominal and would have worried me BUT band 1 is exactly the one that works Conclusion: it would seem that the culprit is the second converter and in particular (probably) the internal switch that has the sole task of letting the signal? (which is already at 321.4MHz and does not need to be converted)?pass from its input to the output
In the next few days I will test the converter that meanwhile?has been?disassembled?; In the meantime I found a cheap one on the bay that should arrive in about ten days
Yves, I have a question: on the block diagram A3A4 is represented as a block that has 5 ports of which one (J5) would seem to be the connector that carries the power and the DC that controls the switch and that connects to A7 Analog Interface through the W35 cable
Actually,?this connector on the real component, does not have a name
Instead,?the name J5?, stamped on the case , indicates an SMB connector that has the writing LO TEST and in my analyzer?it is the one that?conveys the 600MHz LO signal? Now,?on the block diagram the connector that conveys the 600MHz signal has the name J4 (in my analyzer, the J4 connector was disconnected) This confusion of names and roles made me doubt that years ago, when I had disassembled this section I had not reassembled it correctly thanks again and best regards ----- Messaggio originale ----- Inviato: 06/09/2024 23:21:52 Oggetto: Re: [HP-Agilent-Keysight-equipment] HP 5086-7906 YTO
Hi Adri, ? I had sent you the measurements of the RF input-output mixer signals verification, I had disassembled the High Frequency section of my 8595E to be able to provide you with this information. If you have no more questions relating to this section, I will close my 8595E and do a flatness check to see if everything is correct. ? Yves ? ? thank you very much for all the suggestions and information with which I will continue my investigation
In the meantime I received the 2.5mm socket wrench and after?a little mod to adapt it?for the purpose (photo), I proceeded to align the spheres of the SYTF
I must say that the operation done under the microscope is quite simple
The nuts must be loosened (not too much) and with a small screwdriver that acts as a delicate lever, ?the supports of?the?spheres can be moved so that the coupling ring completely shadows them (i.e. the sphere is exactly in the center)
Removing the gold mesh was not necessary
The insertion loss has improved enormously:
at 5 GHz it is -6dBm at 6GHz it is -10dB (before the signal starting from this frequency was no longer visible) at 6.5 GHz it is only -3dB
I will install it when I have solved the problem of "blindness" in band 0 since the calibration constants that the instrument has in memory (in practice the tuning current data) are relative to the original SYTF and the "new" SYTW requires a? SYTF CAL is done
|
Hi, ? Good news. ? I just reassembled my 8595E, and after some checks, everything seems normal. ? I put a comparative image between our two Spectrum. I also did a sweep in 100 kHz to better see the harmonics in high frequencies. So, I pasted two images from 0Hz-3GHz and 3GHz to 6GHz. Input attenuator at 0dB, Reference level at -20dBm. ? Yves ? ? hello Yves,
I received the 2nd converter and, after testing it on the bench (if you are interested I will give you the two test configurations) I installed it and voil¨¤, the machine is back to working like in the old days
It passes the amplitude and frequency calibrations and the confidence test without any problem
As it happened before the death of the YTO the analyzer still has a certain "deafness" after 5.5GHz
By virtue of the alignment of the spheres that I did a few weeks ago The defect is milder than it was then and I think it is due to a sub-optimal loss of insertion of the SYTF A3A2 As proof of the "deafness", while all the calibration routines, including the CAL YTF routine are performed without problems, the CAL MXR is not completed and gives the message CAL: HARMONICS INSUFFICIENT In fact I attach a screen of the 300MHz calibration signal from which it would seem that the very last harmonics are missing
Thank you in advance if can you send the analogous screen of your analyzer
In a few days I will receive a more reliable 6GHz RF generator than the current one and I will use it to try to perfect the alignment
Yves, I think that now you can reassemble and close your analyzer :-) Many thanks for all the measurements that you sent me and that were useful to trace the problem!
Adri
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Show quoted text
----- Messaggio originale ----- Inviato: 08/09/2024 01:35:49 Oggetto: Re: [HP-Agilent-Keysight-equipment] HP 5086-7906 YTO
Hi Adri ? Here are the measurements connected to the first 2 converters as a reference. ? For the second converter I get a voltage of -1.678V instead of -3.5V as written in the service manual, I would say that we have similar voltages for this particular point. It seems far from the nominal point, but there may be an error in the manual. ? You are close to the goal, and this module may be repairable if there is no micro circuit, I have never opened a second converter in this series, but it is a possibility. ? When you open your second converter, send me pictures, I'm curious. ? Yves ? dear Yves, I didn't realize that you had made the measurements expressly to help me! I owe you then a double (even triple) thanks! Especially considering the fact that the front end of this instrument is really very dense, complicated and delicate! After my last email, in addition to doing the (essentially mechanical) intervention on the SYTF, I continued to check the input signal through the various sections by alternately injecting 300MHz @-20dBm and 5GHz @0 dBm The signals were found to be in specification up to the A3A9 bandpass (where the two paths join to form the intermediate frequency of 321.4MHz). At this point I could see the 5GHz signal (converted), present at that point at -47dBm (the specification says -43/-56dBm).
Instead, no trace of the 300MHz input signal
Investigatine?the second converter A3A4 in more depth
I checked?the signals at its input
On J1 there is 3.9214GHz at -46dBm? --->OK
On J3 there is 321.4MHz @ -37.7dBm? --->OK
On J4 I did not check 600MHz @-1dBm but the fact that the converter works in band 1 tells me that the oscillator is present and is in specification
The power supply is quite OK (5V are actually 4.75; 10V are 9.98 and the DC that controls the internal switch that should be +15V? (band 0) and -3.5V?(band 1) is actually +14.60V and -1.35V
This last value is rather far from the nominal and would have worried me BUT band 1 is exactly the one that works Conclusion: it would seem that the culprit is the second converter and in particular (probably) the internal switch that has the sole task of letting the signal? (which is already at 321.4MHz and does not need to be converted)?pass from its input to the output
In the next few days I will test the converter that meanwhile?has been?disassembled?; In the meantime I found a cheap one on the bay that should arrive in about ten days
Yves, I have a question: on the block diagram A3A4 is represented as a block that has 5 ports of which one (J5) would seem to be the connector that carries the power and the DC that controls the switch and that connects to A7 Analog Interface through the W35 cable
Actually,?this connector on the real component, does not have a name
Instead,?the name J5?, stamped on the case , indicates an SMB connector that has the writing LO TEST and in my analyzer?it is the one that?conveys the 600MHz LO signal? Now,?on the block diagram the connector that conveys the 600MHz signal has the name J4 (in my analyzer, the J4 connector was disconnected) This confusion of names and roles made me doubt that years ago, when I had disassembled this section I had not reassembled it correctly thanks again and best regards ----- Messaggio originale ----- Inviato: 06/09/2024 23:21:52 Oggetto: Re: [HP-Agilent-Keysight-equipment] HP 5086-7906 YTO
Hi Adri, ? I had sent you the measurements of the RF input-output mixer signals verification, I had disassembled the High Frequency section of my 8595E to be able to provide you with this information. If you have no more questions relating to this section, I will close my 8595E and do a flatness check to see if everything is correct. ? Yves ? ? thank you very much for all the suggestions and information with which I will continue my investigation
In the meantime I received the 2.5mm socket wrench and after?a little mod to adapt it?for the purpose (photo), I proceeded to align the spheres of the SYTF
I must say that the operation done under the microscope is quite simple
The nuts must be loosened (not too much) and with a small screwdriver that acts as a delicate lever, ?the supports of?the?spheres can be moved so that the coupling ring completely shadows them (i.e. the sphere is exactly in the center)
Removing the gold mesh was not necessary
The insertion loss has improved enormously:
at 5 GHz it is -6dBm at 6GHz it is -10dB (before the signal starting from this frequency was no longer visible) at 6.5 GHz it is only -3dB
I will install it when I have solved the problem of "blindness" in band 0 since the calibration constants that the instrument has in memory (in practice the tuning current data) are relative to the original SYTF and the "new" SYTW requires a? SYTF CAL is done
|
hello Yves,
I received the 2nd converter and, after testing it on the bench (if you are interested I will give you the two test configurations) I installed it and voil¨¤, the machine is back to working like in the old days
It passes the amplitude and frequency calibrations and the confidence test without any problem
As it happened before the death of the YTO the analyzer still has a certain "deafness" after 5.5GHz
By virtue of the alignment of the spheres that I did a few weeks ago The defect is milder than it was then and I think it is due to a sub-optimal loss of insertion of the SYTF A3A2
?
As proof of the "deafness", while all the calibration routines, including the CAL YTF routine are performed without problems, the CAL MXR is not completed and gives the message CAL: HARMONICS INSUFFICIENT In fact I attach a screen of the 300MHz calibration signal from which it would seem that the very last harmonics are missing
Thank you in advance if can you send the analogous screen of your analyzer
In a few days I will receive a more reliable 6GHz RF generator than the current one and I will use it to try to perfect the alignment
Yves, I think that now you can reassemble and close your analyzer :-) Many thanks for all the measurements that you sent me and that were useful to trace the problem!
Adri
?
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Show quoted text
----- Messaggio originale -----
Inviato: 08/09/2024 01:35:49
Oggetto: Re: [HP-Agilent-Keysight-equipment] HP 5086-7906 YTO
Hi Adri
?
Here are the measurements connected to the first 2 converters as a reference.
?
For the second converter I get a voltage of -1.678V instead of -3.5V as written in the service manual, I would say that we have similar voltages for this particular point.
It seems far from the nominal point, but there may be an error in the manual.
?
You are close to the goal, and this module may be repairable if there is no micro circuit, I have never opened a second converter in this series, but it is a possibility.
?
When you open your second converter, send me pictures, I'm curious.
?
Yves
?
dear Yves, I didn't realize that you had made the measurements expressly to help me! I owe you then a double (even triple) thanks! Especially considering the fact that the front end of this instrument is really very dense, complicated and delicate!
After my last email, in addition to doing the (essentially mechanical) intervention on the SYTF, I continued to check the input signal through the various sections by alternately injecting 300MHz @-20dBm and 5GHz @0 dBm
The signals were found to be in specification up to the A3A9 bandpass (where the two paths join to form the intermediate frequency of 321.4MHz). At this point I could see the 5GHz signal (converted), present at that point at -47dBm (the specification says -43/-56dBm).
Instead, no trace of the 300MHz input signal
Investigatine?the second converter A3A4 in more depth
I checked?the signals at its input
On J1 there is 3.9214GHz at -46dBm? --->OK
On J3 there is 321.4MHz @ -37.7dBm? --->OK
On J4 I did not check 600MHz @-1dBm but the fact that the converter works in band 1 tells me that the oscillator is present and is in specification
The power supply is quite OK (5V are actually 4.75; 10V are 9.98 and the DC that controls the internal switch that should be +15V? (band 0) and -3.5V?(band 1) is actually +14.60V and -1.35V
This last value is rather far from the nominal and would have worried me BUT band 1 is exactly the one that works
Conclusion: it would seem that the culprit is the second converter and in particular (probably) the internal switch that has the sole task of letting the signal? (which is already at 321.4MHz and does not need to be converted)?pass from its input to the output
In the next few days I will test the converter that meanwhile?has been?disassembled?; In the meantime I found a cheap one on the bay that should arrive in about ten days
Yves, I have a question: on the block diagram A3A4 is represented as a block that has 5 ports of which one (J5) would seem to be the connector that carries the power and the DC that controls the switch and that connects to A7 Analog Interface through the W35 cable
Actually,?this connector on the real component, does not have a name
Instead,?the name J5?, stamped on the case , indicates an SMB connector that has the writing LO TEST and in my analyzer?it is the one that?conveys the 600MHz LO signal?
Now,?on the block diagram the connector that conveys the 600MHz signal has the name J4 (in my analyzer, the J4 connector was disconnected)
This confusion of names and roles made me doubt that years ago, when I had disassembled this section I had not reassembled it correctly
thanks again and best regards
----- Messaggio originale -----
Inviato: 06/09/2024 23:21:52
Oggetto: Re: [HP-Agilent-Keysight-equipment] HP 5086-7906 YTO
Hi Adri,
?
I had sent you the measurements of the RF input-output mixer signals verification, I had disassembled the High Frequency section of my 8595E to be able to provide you with this information.
If you have no more questions relating to this section, I will close my 8595E and do a flatness check to see if everything is correct.
?
Yves
?
?
thank you very much for all the suggestions and information with which I will continue my investigation
In the meantime I received the 2.5mm socket wrench and after?a little mod to adapt it?for the purpose (photo), I proceeded to align the spheres of the SYTF
I must say that the operation done under the microscope is quite simple
The nuts must be loosened (not too much) and with a small screwdriver that acts as a delicate lever, ?the supports of?the?spheres can be moved so that the coupling ring completely shadows them (i.e. the sphere is exactly in the center)
Removing the gold mesh was not necessary
The insertion loss has improved enormously:
at 5 GHz it is -6dBm at 6GHz it is -10dB (before the signal starting from this frequency was no longer visible) at 6.5 GHz it is only -3dB
I will install it when I have solved the problem of "blindness" in band 0 since the calibration constants that the instrument has in memory (in practice the tuning current data) are relative to the original SYTF and the "new" SYTW requires a? SYTF CAL is done
|
Reference card for HP8901B
Hi All,
Buoyed?by Wilko's recent success, I wonder if anyone has a pull out reference card for the 8901B?
|
Re: HP 8360 B and L manuals
John,
I¡¯ll take them if they¡¯re still available. They should be able to go by media mail.?
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On Sep 10, 2024, at 2:30?PM, John Brown via groups.io <w0mpm.john@...> wrote:
? Have two binders to get rid of. Both in the oem plastic wrap. If anyone is interested I¡¯ll see what is the cost to mail. And maybe $20 for the two.
?
HP 8360 B-Series Swept Signal Generator/
HP 8360 L-Series Swept CW Generator
Troubleshooting Guide
packaging sez February 1999 part num 08360-90124
?
and
?
HP 8360 B-Series Swept Signal Generator/
HP 8360 L-Series Swept CW Generator
Service Guide
packaging sez February 1999 part num 08360-90125
?
?
--
W0MPM John
|
Have two binders to get rid of. Both in the oem plastic wrap. If anyone is interested I¡¯ll see what is the cost to mail. And maybe $20 for the two.
?
HP 8360 B-Series Swept Signal Generator/
HP 8360 L-Series Swept CW Generator
Troubleshooting Guide
packaging sez February 1999 part num 08360-90124
?
and
?
HP 8360 B-Series Swept Signal Generator/
HP 8360 L-Series Swept CW Generator
Service Guide
packaging sez February 1999 part num 08360-90125
?
?
--
W0MPM John
|
HP 11592-60016 cable surplus to requirements
I have a HP 11592-60016 cable for servicing HP 141T spectrum analysers, in pristine condition, that is surplus to requirements.
?
One like this:
?
Please contact me via private message if you are interested. Cable is located in NL.
?
Vy73 Wilko
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Re: looking for a scan of the HP8901A pull out reference card
Thanks to a couple of kind folks I now have a high-resolution (scanned) copy of the pullout reference card. Many thanks for that!
?
I just uploaded it to the BAMA archive, so I assume it will be publicly visible at some point in the future. Should you want it earlier, please reach out in a PM and I will email you a copy (JPG, 5.7 MB). The uncompressed TIFF is a bit unwieldy at 147 MB ;-)
?
Wilko
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Re: 8566B attenuator removal
Although this isn't the precise same attenuator as the one I'm investigating, these links are still very useful for the info they contain concerning the aspects of this technology which are common to all attenuators of this kind, and others may find it valuable. Thanks for posting.
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Re: 5343A equivalency to 5351B
Hi, ? I'm not sure I understand the question, but the 2 RF inputs on the front of a 5343A correspond to the two on the 5351B, as shown in the picture. ? For the INTFC signal, it is an internal synchronization signal, between the 8350B and the plug-ins. But to be able to make a measurement with a meter, you have to use the two BNC connectors 'CNTR TRIG' and 'STOP SWEEP'. The problem is that the 5351B meter does not have an INTFC B input, but the 5343A speaker does. So, if you have this meter, it would be possible to do it. ? 
? 
? ? Yves ? ? ? I'm trying to calibrate an HP8350B+Hp83592A plug in with an HP5351B can anyone help me with the 2 terminals labelled SWP? INTFC?? A? &? B on HP5343A which terminals are equivalent on HP5351B ? (if there is any)
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5343A equivalency to 5351B
Hello,
I'm trying to calibrate an HP8350B+Hp83592A plug in with an HP5351B
can anyone help me with the
?
2 terminals labelled SWP? INTFC?? A? &? B on HP5343A
?
which terminals are equivalent on HP5351B ? (if there is any)
|
Re: HP 339A Distortion Test Set repair/refurbish (hamfest find) (long read)
The is also a modification for a second harmonic trim which uses feedback around the fet via a 2k trimmer. I have implemented this in a clone I built of the oscillator section and it makes a very marked improvement in reducing the 2H level.?
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Re: HP 339A Distortion Test Set repair/refurbish (hamfest find) (long read)
The oscillator IC is the Harris HA2625 which is discontinued. I believe the LT1468 is a suitable replacement. The HA2625 is also used as the product amplifier to drive the true RMS converter IC, an AD536 (still available albeit expensive). The HA2625 is used elsewhere in the unit, once you know one HP part number you can find all the similar ICs. The AD536 is a great chip for RMS if you drive it with a large signal. It¡¯s very accurate below about 200-300khz. The AD637 is better if you want more frequency response but the pins are completely different (I digress). The oscillator uses a VCR2N fet for level control. You can find them second hand or try a 2N4091 or 2N4092 which are available from Mouser. The 4091 being the better choice.?
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Re: HP 339A Distortion Test Set repair/refurbish (hamfest find) (long read)
Hi Jim, et al.
I have an HP339A on my bench so I'm following this discussion thread with interest. My unit was manufactured in 1983 and currently needs some TLC. I offer some of the things that I have learned as I used my unit.
?
On Sun, Sep 8, 2024 at 06:54 PM, Jim wrote:
...I looked through the schematic at the section for the monitor output and it's a simple path from the main meter circuitry (which appears to be working) - just a resistor, fuse and then the isolation relay. I hear the relay get activated/deactivated, so once I have the unit open again I will probe that path and see where the signal stops. I am hoping that it's just the 0.062A fuse.?
Note that the monitor output is disabled when the OSCillator LEVEL FUNCTION is selected. Reference manual sections 3-28 & 3-37. I did need to replace the 62mA fuse in my unit after I inadvertently applied an external signal to the front panel Output Monitor terminals. I was very happy to learn that the instrument was protected from such operator mistakes.
On Sun, Sep 8, 2024 at 06:54 PM, Jim wrote:
Did I read somewhere where HP did not include the schematic for the 339A's oscillator itself in the service manual?
My manual does include a foldout schematic of the oscillator circuits. However, the oscillator circuit uses two OP Amp ICs that are listed as manufactured by HP.
?
When I was considering the purchase of my unit it was still easy to talk to a live person at an HP service center. The rep told me that "The most common failure in the 339 is the switches which wear out or get dirty. The frequency switches wear out the most with the distortion range switch next. It takes about 2 hours to change the switches so they often just change the complete PCB assembly. Both approaches are expensive. They don¡¯t use any special cleaner just a good quality contact cleaner."
?
Enjoy your 339A Jim.
Cheers,
Tom.
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Re: HP 339A Distortion Test Set repair/refurbish (hamfest find) (long read)
I have a 339A that I am about to press into service unfortunately it hasn¡¯t been switched on for over 5 years so will probably require a bit of attention I have uploaded the service manuals to this sight Could I ask if you find any information or notes that you upload them to the files on this sight I am also interested in the baseline measurements on the 339A you talk about Regards Paul ?
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From: [email protected] [mailto:[email protected]] On Behalf Of Jeremy B
Sent: 09 September 2024 20:13
To: [email protected]
Subject: Re: [HP-Agilent-Keysight-equipment] HP 339A Distortion Test Set repair/refurbish (hamfest find) (long read) ? Great find. The 339A is a great improvement over the 333. I have the 339A and 334A, both are very useful instruments. Mine has been seeing a lot of work lately with my current project. Let me know if you need any baseline measurements on the 339A and I¡¯ll try and help you out. Once you get it working I¡¯d recommend checking online for the improvements which can be made. There¡¯s a very comprehensive list on one of the audio forums (audio karma I think). Mine bottoms out around 0.0012% at 1khz but that can be improved.?
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Re: HP 339A Distortion Test Set repair/refurbish (hamfest find) (long read)
Great find. The 339A is a great improvement over the 333. I have the 339A and 334A, both are very useful instruments. Mine has been seeing a lot of work lately with my current project. Let me know if you need any baseline measurements on the 339A and I¡¯ll try and help you out. Once you get it working I¡¯d recommend checking online for the improvements which can be made. There¡¯s a very comprehensive list on one of the audio forums (audio karma I think). Mine bottoms out around 0.0012% at 1khz but that can be improved.?
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Re: E4438c display problem, controler memory location please
I'll? sure check out the psu caps. This gen has about 40000 hours on the clock. Original seal's intact. When I opened it up found it's like new inside. No dust or dirt anywhere, my guess is it must have spent it's working life in a clean room. Has all board's fitted and a number of options. I didn't make a proper note but think it was drawing over 200W.
Many thanks John
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Re: E4438c display problem, controler memory location please
On a more general note, I would strongly recommend that you check/replace the main bulk capacitor in the main switched mode PSU module if it hasn't already been done. This is a known weak point once the E4438C sig gen has seen a lot of use. It failed in mine but luckily the previous owner immediately stopped trying to use it once it failed.
?
Keysight looked at it and claimed that they couldn't repair it (they said the PSU module is obsolete) so I was able to??acquire the E4438C sig gen as BER.?Once it was mine, I replaced the cap and it has been fine ever since. There are plenty of pictures online of failed PSUs in these sig gens. If the bulk cap fully fails with low capacitance and high ESR then other components in the PSU are likely to fail in a big way. So it is worth replacing this cap.
?
I think I used this 220uF 400V cap from Mouser with Mouser part number ?661-ETXH401N221MR35S. It is a higher spec version of what was already in the PSU with a longer lifetime and it only costs about ?4. Same manufacturer, same dimensions. However, the voltage rating is the same at only 400V. It might be worth trying to find one rated to 450V.?
?
?
The other thing to be aware of is that these sig gens consume a lot of power when running. Mine has lots of hardware options fitted and it can exceed 200W power consumption when I measure it under certain operating modes. The datasheet says <300W. It isn't really suited as a general purpose sig gen because of this. I only use it when I need the special features or the high performance it offers.
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Re: E4438c display problem, controler memory location please
Thank you Mark
I have seen that part of the clip. Mine is a different release, not sure if newer or older but made in 2005 or 6. All lcd drive circuits appear to be on cpu card. Can't find a lcd controler chip so assume is been put in fpga. Have ordered both ram chips, will start with the 4Mb one.
John
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Jared Cabot
John W0MPM
Jinxie
Tom Phillips
Paul Bicknell