Thanks for the excellent video. I couldn't have repaired the attenuator in my HP 8593E spectrum analyzer without it. I would never have suspected o-rings would cause intermittent operation of the plungers. I found the o-ring kit you used on ebay for $10. Saved me like $500 on a rebuilt unit.
How did your repair go? was the disassembly very different than the one in video? Any particular advice? I need to do it on my 8596E. I think the attenuator must be the same as 8593E or very similar.
@@amirb715 Most of the work was removing the front end assembly to get to the attenuator. Repair manual is essential to find all the screws and wires that need to be removed and disconnected in the correct order. Taking photos as I proceeded helped with re-assembly. It's similar to pulling a car engine :). Once attenuator is removed it is easily disassembled. Separating the solenoids from the attenuator part may be different than the attenuator in the video. Since it wasn't shown I had to figure it out myself. There are 8 hex head screws that need to be loosened (not removed) to let the steel covers come off the solenoids. Hard to describe. Pics here: www.dropbox.com/s/vf5mr56nd21tig9/hp8593e.zip?dl=0 Link to repair manual: www.av.it.pt/medidas/data/Manuais%20&%20Tutoriais/15%20-%20HP%20Spectrum%20Analyser%208593E/HP8593E%20Service%20Guide.pdf
Hi I have the same SA and mine is about 60db down on what it should be reading at around 100mhz and the amount its down by gets less as you measure higher frequencies. Just wondering if yours had similar symptoms before you fixed the attenuator. Everything else works as it should so I suspect the Att unit or connections in and out of it.
Thanks for the quick follow-up posting. Good point regarding the physical sizes of the attenuator pads and matching to the size of the contact leaves. Worth noting that the plungers are some kind of plastic and could snap if bent.
Pulling and reinserting the pins can be done by sliding the rack that the contacts are mounted on first. Basically moving the pin to the center of one of the holes first. This will avoid any damage to the pins or the contacts. The rack should move fairly easily with a small plastic diddle stick.
@@idpromnut Thanks. That meter sure has a lot of issues for something that was certified and has been released for 2 years. Too bad as it seemed like the brand could have made it a real winner.
Have you ever ordered replacement pads for those attenuators? I use the 8496G and 8494G on daily basis and have written software test programs that use them (With the 11713A or B switch driver controller). Occationally we have to send them off to get repaired. Yo mention they are expensive. Brand new, the 8496/8494 are now around $1300 USD each! I started buying used ones from Spectrum Technologies for about $500 a set certified. They probably get them on ebay, fix as needed and the certify them and sell them.
several attenuator pads can still be ordered directly from Keysight. I think they were around $50-$80 depending on the size (10dB, 20dB, 40dB etc) even the push rods with o-rings on them can still be bought from keysight for about $15-$20 each.
Great video, I got today an Agilent E4432D RF generator via eBay which has an attenuator problem, it is very likely that it is the o.ring problem. Regards from Hannover/Germany,
I'm having some problems because it appears those cap head screw used in this thing are an usual M2.2 diameter which nobody on the planet seems to carry. All I can find is M2.5 which I'm sure will be too big. Some of the screws I'm dealing with have the hex head stripping out on them. It would be nice to replace them with new ones.
Thanks for the great video! I have started repairing the input attenuator in my HP8596E (o-ring problem). The little amount of epoxy securing the plunger tips was damaged (I found parts of it at the attenuator pads), so I have cleaned it up. My question is: do I have to add new securing epoxy? And what is the best way to do it (large drop pf epoxy will attach the plunger tip to the metal strip, preventing the full motion range).
Is the attenuator in an HP 8662A of similar construction, and can it be serviced in the same way? Currently working on an 8662A, and it appears to have issues with the output level...
Thanks for this video. I try test electronicly a 08340-60175 (33323V) attenuator which need 5 Volt. These have 2 solenoids per pad. Would it work when i attached just 5 volt to these 2 solenoids to activate that pad?
Hi, thanks for the great tutorial video. Do these HP RF Attenuators require lubricant on their o-rings or any other mechanical components to maintain their switching life span??
When I disassembled both of my attenuators, I did not see any evidence of lubricant used initially during manufacturing, so I am assuming that all you need are o-rings that are pliable and of the correct sizing. It may function better to put a very small amount of non-conductive switch lubricant at the back of the plunger (where it is in partial contact with the solenoid) but even then, I don't think this is strictly necessary.
@@idpromnut What about the lubricant at the metal strips which are driven by plungers? I have noticed some amount of it in my unit, do you know where could it come from?
@@radiowiec223 Are you talking about where the plungers attach to the metal strips? I didn't see any lubricant on those either; you could put a bit of lubricant on those areas, but keep in mind those o-rings are consumables. Lub might increase the number of life-cycles you get out of them but they will eventually need to be replaced again.
Thanks for the excellent video. I couldn't have repaired the attenuator in my HP 8593E spectrum analyzer without it. I would never have suspected o-rings would cause intermittent operation of the plungers. I found the o-ring kit you used on ebay for $10. Saved me like $500 on a rebuilt unit.
How did your repair go? was the disassembly very different than the one in video? Any particular advice? I need to do it on my 8596E. I think the attenuator must be the same as 8593E or very similar.
@@amirb715 Most of the work was removing the front end assembly to get to the attenuator. Repair manual is essential to find all the screws and wires that need to be removed and disconnected in the correct order. Taking photos as I proceeded helped with re-assembly. It's similar to pulling a car engine :). Once attenuator is removed it is easily disassembled. Separating the solenoids from the attenuator part may be different than the attenuator in the video. Since it wasn't shown I had to figure it out myself. There are 8 hex head screws that need to be loosened (not removed) to let the steel covers come off the solenoids. Hard to describe. Pics here: www.dropbox.com/s/vf5mr56nd21tig9/hp8593e.zip?dl=0
Link to repair manual: www.av.it.pt/medidas/data/Manuais%20&%20Tutoriais/15%20-%20HP%20Spectrum%20Analyser%208593E/HP8593E%20Service%20Guide.pdf
Hi I have the same SA and mine is about 60db down on what it should be reading at around 100mhz and the amount its down by gets less as you measure higher frequencies. Just wondering if yours had similar symptoms before you fixed the attenuator. Everything else works as it should so I suspect the Att unit or connections in and out of it.
Thanks for the quick follow-up posting.
Good point regarding the physical sizes of the attenuator pads and matching to the size of the contact leaves.
Worth noting that the plungers are some kind of plastic and could snap if bent.
Pulling and reinserting the pins can be done by sliding the rack that the contacts are mounted on first. Basically moving the pin to the center of one of the holes first. This will avoid any damage to the pins or the contacts. The rack should move fairly easily with a small plastic diddle stick.
Thanks! I loved the series you did on the EEVBlog DMM testing!
@@idpromnut Thanks. That meter sure has a lot of issues for something that was certified and has been released for 2 years. Too bad as it seemed like the brand could have made it a real winner.
Marvelous! Simply marvelous! Thanx much
same problem in my HP 8594E, thank you!
Have you ever ordered replacement pads for those attenuators? I use the 8496G and 8494G on daily basis and have written software test programs that use them (With the 11713A or B switch driver controller). Occationally we have to send them off to get repaired. Yo mention they are expensive. Brand new, the 8496/8494 are now around $1300 USD each! I started buying used ones from Spectrum Technologies for about $500 a set certified. They probably get them on ebay, fix as needed and the certify them and sell them.
several attenuator pads can still be ordered directly from Keysight. I think they were around $50-$80 depending on the size (10dB, 20dB, 40dB etc) even the push rods with o-rings on them can still be bought from keysight for about $15-$20 each.
Great video, I got today an Agilent E4432D RF generator via eBay which has an attenuator problem, it is very likely that it is the o.ring problem.
Regards from Hannover/Germany,
I'm having some problems because it appears those cap head screw used in this thing are an usual M2.2 diameter which nobody on the planet seems to carry. All I can find is M2.5 which I'm sure will be too big. Some of the screws I'm dealing with have the hex head stripping out on them. It would be nice to replace them with new ones.
Thanks for the great video! I have started repairing the input attenuator in my HP8596E (o-ring problem). The little amount of epoxy securing the plunger tips was damaged (I found parts of it at the attenuator pads), so I have cleaned it up. My question is: do I have to add new securing epoxy? And what is the best way to do it (large drop pf epoxy will attach the plunger tip to the metal strip, preventing the full motion range).
I don't recall seeing any epoxy on my unit, but I may have just missed it. I'm not sure what the best way to fix that particular problem is.
Is the attenuator in an HP 8662A of similar construction, and can it be serviced in the same way? Currently working on an 8662A, and it appears to have issues with the output level...
Thanks for this video. I try test electronicly a 08340-60175 (33323V) attenuator which need 5 Volt. These have 2 solenoids per pad. Would it work when i attached just 5 volt to these 2 solenoids to activate that pad?
Yep, that should work. You also should be able to trace back the wires to that solenoid to the connector and power it from there if you wanted.
Thank you for the video.
Hi, thanks for the great tutorial video.
Do these HP RF Attenuators require lubricant on their o-rings or any other mechanical components to maintain their switching life span??
When I disassembled both of my attenuators, I did not see any evidence of lubricant used initially during manufacturing, so I am assuming that all you need are o-rings that are pliable and of the correct sizing. It may function better to put a very small amount of non-conductive switch lubricant at the back of the plunger (where it is in partial contact with the solenoid) but even then, I don't think this is strictly necessary.
@@idpromnut What about the lubricant at the metal strips which are driven by plungers? I have noticed some amount of it in my unit, do you know where could it come from?
@@radiowiec223 Are you talking about where the plungers attach to the metal strips? I didn't see any lubricant on those either; you could put a bit of lubricant on those areas, but keep in mind those o-rings are consumables. Lub might increase the number of life-cycles you get out of them but they will eventually need to be replaced again.
Hi Sir, how this electronic attenuator work?would you mind to teach me?
Hi idpromnut, I made a comment in your video regarding the hp 8559 spectrum analyzer on july 2 2015. I hope this will help with snap shot problem.
Nice.