Re: HP 8640B Attenuator Repair
Do you know what mechanism causes the contacts to be "cleaned"??? I wonder if this method would work on other types of contacts that are "fuzzy".?
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Re:-
"You cannot put these on your network for security reasons as they're completely prone to viruses and other attacks."
True...?? Also, you don't know what might already have got in and has infested it's OS, just waiting for another LAN and it's residents to "have a go at".
I speak from experience re that.? In a past job, we had a demo HP VNA to evaluate.? I forget the exact model, but avery nice instrument indeed.? The salesman said that it can print measurement results to a network printer...? So we tried.? (Na?ve that we were back then...)
Within 10 minutes, other people in the office were complaining their PC's were running slow and behaving strange.
Again, I forget exactly what it was, but when investigated, that "Demo" VNA was utterly infested with all the (then) current (and plenty of old) common Windows malware, and two of them had "got out"...
(We had AV of course, but our IT people back then had failed to keep it up to date.? Manual updates, we only had dial-up internet access then.)
When we informed HP (UK sales office) they seemed unconcerned (this was a while ago.)? So, I wonder how many other potential customers got hit, or even contributed to the infestation.
"Trust No One", and NEVER connect anything you don't know the the full history of, to your LAN, unless you can sweep it first and verify it is clean.
Take care.
Dave B.
Ex Technical Manager AR UK Ltd, and before that EMV Ltd.
PS:? It's not "Just" a Windows problem either.? Some commodity Network Attached Storage devices, have intentional functionality to reach out and attempt to scan the other LAN residents by default, for whatever reason!?? Some too, have a default "phone home" facility!? (Wherever "home" might be...)
--
Sent from a MicroSoft free zone:
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Re: Help figuring out my 8648C Signal Generator?....
Thanks for the photos!
I can confirm that I do not have options 1E2 or 1E6 as the parts don't exist in my unit. They aren't options I need anyway so no problems there.
The 1EA high power option is intriguing me though. With no reference to special parts in the 'Replaceable Parts' section of the service manuals I have found online, I'm wondering how a repair technician is to ensure that the option still works if the mysterious critical part is inadvertently replaced? How to ensure the part is not replaced with a non option part if there is no differentiation in the manual?
Which has me thinking further, is it just a software option? Maybe it changes the gain settings on the amplifier or attenuator settings to allow more upper range?
I wonder if just using the adjustment software etc to tell the instrument that it has the option installed will enable it?
Worth digging deeper I think, that high power option is a useful one...
Jared.
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The following files and folders have been uploaded to the Files area of the [email protected] group.
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/Bench Briefs, Product Notes, Service Notes, Journals, Tutorials and White Papers/HP Measurement and Computation News/1975_May_Jun_HP_Measurement_And_Computation_News.pdf
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/Bench Briefs, Product Notes, Service Notes, Journals, Tutorials and White Papers/HP Measurement and Computation News/1976_May_Jun_HP_Measurement_And_Computation_News.pdf
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/Bench Briefs, Product Notes, Service Notes, Journals, Tutorials and White Papers/HP Measurement and Computation News/1978_Jul_Aug_HP_Measurement_And_Computation_News.pdf
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/Bench Briefs, Product Notes, Service Notes, Journals, Tutorials and White Papers/HP Measurement and Computation News/1980_Jan_Feb_HP_Measurement_And_Computation_News.pdf
By: Wolfgang Schraml <wschraml@...>
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Re: Help figuring out my 8648C Signal Generator?....
The B/C/D units have the A10 frequency extension board which is on the far side of the card cage and encased in a cast aluminum housing (the first photo showing the barcode). I don¡¯t think the A10 is used for the A models.
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Re: Help figuring out my 8648C Signal Generator?....
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Re: 11807E Radio Test Software on PCMCIA Cards for the 8920B
I have NA FM Tests but would be interested in an AM Tests card for an 8924C.
Mike
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Re: 11807E Radio Test Software on PCMCIA Cards for the 8920B
A flashed card would be great just let me know how much and how I can pay.
Andrew
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Re: 11807E Radio Test Software on PCMCIA Cards for the 8920B
And if you don't want to DIY, I can do you a Flash card for small fee...
DIY requires a copy of Memory card Explorer, a PC with a PCMCIA slot (including 12V supply unless your Flash card is 5V) and a linear Flash card.
PM me if you want one.
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Re: 11807E Radio Test Software on PCMCIA Cards for the 8920B
Yes - I wrote up what I did over on EEVBlog (just an FYI, I don't have an 8920B myself, I got one for my Dad back in Aus and did the RFTools stuff while I had it here so, unfortunately, I can't test anything other than flashing to the card):
TonyG
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Thank you Scott. We are staying with the 8753ES. Better the devil we know that is fast enough. If the need arises for a faster system I think it will have to be something current but it will be expensive and probably not repairable. Peter
On Thu, Nov 30, 2023 at 7:56?AM Scott Vance via <scott_l_vance= [email protected]> wrote: Hi Peter,
A quick search on e-bay revealed the following:
1)??E5071C 6.5 Ghz ENA ($4200 - possible issue with output that you may need to verify or rectify).
2)??E8358A Network Analyzer PNA 300KHz to 9GHz (will require a new hard-drive and image, so this will be a little work, but looks like a good machine).? Currently on bid and will probably go for 4K or less.
3)??Agilent E5061A going for $2300.? Only goes up to 1.5 GHz, but if that's all you need then a reasonable option.
A note of warning:? All of these new machines should be considerably faster with similar or perhaps even better dynamic ranges BUT they use early versions of windows.? You cannot put these on your network for security reasons as they're completely prone to viruses and other attacks.? They boot terribly slow (relative to your HP8753 or any recent machine), but once they're up and running they should be much faster for running your actual tests.
I have repaired only a single Agilent machine - an N5230A PNA.? Plenty fast, but also boots slow.
The normal disclaimers:? do your own research before you buy, look for buyers who accept returns, don't buy anything that you can't fix, etc.
Good luck!
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11807E Radio Test Software on PCMCIA Cards for the 8920B
Is it still possible to acquire this card and software??
Drew
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Re: HP 8640B Attenuator Repair
Great description Don, thanks for sharing.
Bob
On Wednesday, November 29, 2023 at 11:31:45 PM CST, Don Brown, N3DEB <dbawatsonville@...> wrote:
For those interested, I have had great results repairing this 8640B output attenuator.? Symptoms were non linear attenuation, and signal drop out on some levels. Drop out could be restored by switching levels back and forth. Looked like typical bad contact at a pad switch, and I excluded the attempt of replacing specialized components of these hand tuned units.
Certainly locating a donor unit might provide an alternative, but I was hoping to reuse this attenuator to avoid potential re-calibration considerations.
Removed bottom cover to view pads, nothing visibly burned. Applied 10ma constant current DC from attenuator input to output and rotated knob through ranges a few times. I found this suggestion somewhere in this group I think and thank that person for the tip. Note that one DC contact point has to be behind the visible capacitor in series at the output. The other just clip to input connector solder point.
Reinstalled - much better but not quite right. Removed, repeated, reinstalled. Result is as perfect of a result as I could expect, or at least as good as my spectrum analyzer can measure.
For long term protection I added two part epoxy to the wiper contacts on the rear vernier assembly. I have seen these fall out and go missing on others.
Inspecting the acrylic cams inside the attenuator found some were cracking. Applied proper "Weld-On #3" acrylic cement with applicator needle to each cracked cam. (On another unit I drove the cams off the shaft, reamed out the shrinking hole to prevent future contraction cracking, and glued back one cam that completely separated. I think this is the best course.)
Probably by now most ALL units have cracking cams from shrinking with age - I am at four out of five that I have worked on. Applied a little silicone grease that is safe for the acrylic / polycarbonate lobes, hoping to minimize rotation stress where the shaft meets the cams. This is the stress point that finally breaks the cam in two.
I am no engineer or repair professional, but I am persistent and mechanically inclined. There is more that can be done to these 8640Bs as other postings discuss, but this fix got the unit back on the bench for use.
Hope this helps someone.
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Re: Looking or HP 4191A "Performance Test Program" disk
I would find that useful too¡ Could be adaptable for the 4192A which we have¡ Regards Nigel ?
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Show quoted text
From: [email protected] <[email protected]> On Behalf Of vk2bea via groups.io
Sent: Thursday, November 30, 2023 2:22 PM
To: [email protected]
Subject: [HP-Agilent-Keysight-equipment] Looking or HP 4191A "Performance Test Program" disk? I'm looking for a copy of the files on the "Performance Test Program" disk that comes with the service kit for the 4191A RF Impedance Analyzer.
If anyone has this disc and can make the files available please let me know.
thanks
? Michael
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Looking for HP 4191A "Performance Test Program" disk files
I'm looking for a copy of the files on the "Performance Test Program" disk that comes with the service kit for the 4191A RF Impedance Analyzer.
If anyone has this disc and can make the files available please let me know.
thanks
? Michael
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Re: HP 8640B Attenuator Repair
On Wed, Nov 29, 2023 at 09:31 PM, Don Brown, N3DEB wrote:
Hope this helps someone.
Hi N3DEB, Don Great! Thanks for the attenuator repair notes! We have some of these 8640B... some need mechanical repair... or attenuator repair...and I'd like to get them working. So very glad to read about your experience. Best regards. Roy
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Re: Help figuring out my 8648C Signal Generator?....
On Thu, Nov 30, 2023 at 11:21 AM, Mark Bielman wrote:
Hmm. 240VAC mains? I'm aware of this problem but never experienced it. (Thank the magic smoke gods!) When I would check, they all used the sealed EMI filter modules. Fingers crossed!
A lot of the HP gear will report (via HP-IB) the installed options. I did NOT see that command in the User Manual but it might be there. Something like OP? or similar.
Step One: GET IT WORKING!
Step Two: Don't worry about it that much. You will figure it out.
Cheers!
This Rifa popped on only 100V (Japan)! So it must have really been in a bad way..... Once I get a new backup battery from Akihabara tomorrow, and a new contrast pot from Mouser next week, I'll have it all back together again. It was running until the Rifa madness, so it should be all good to go again if I don't break anything else in the mean time. On Thu, Nov 30, 2023 at 01:19 PM, Tom Haynes wrote:
Hi Jared,
?
You will need to do a little choose-your-own-adventure hunt through the manual.
?
Your device is 3426A.
?
The manual on keysight's site is for 4037A/U and doesn't contain errata or a back dating reference.
?
XDEVs has a manual for 3847A/U. It mentions your known replacements but not originals. It also doesn't have back dating.
?
Rensselaer Polytechnic Institute Has a manual for 3816A. Newer part numbers and no back dating.
?
And that is the oldest I can find. Your unit is 4 years older. Those modules have a lot of changes over a short time so it makes sense yours are earlier. For the most part these revisions are minor schematic changes. Sometimes reducing part numbers, replacing out of production parts, safety or stability fixes. The newer schematic are probably fairly close to originals.
?
You can check out my 8662A notes for an idea on how assembly history works.
Thanks for the info! The only manuals I have found around the place for my serial number so far are paper ones on ebay that will cost me US$60 to get into my hands.
Not too much really, but a download is free... :D I'll just have to justify it to myself for a few minutes before I can hit that buy button. haha. If I do buy one, It'll be scanned and uploaded for others to use too.
Also, if anyone has a rear foot/handle or two (P/N 08647-40003) and a front panel (I just need the frame not the buttons and display etc) they can sell, I'm interested.
I drew up the rear foot handle in CAD, so I can get some machined in China from aluminium and anodized for a half decent price anyway.
Jared
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Hi Peter,
A quick search on e-bay revealed the following:
1)??E5071C 6.5 Ghz ENA ($4200 - possible issue with output that you may need to verify or rectify).
2)??E8358A Network Analyzer PNA 300KHz to 9GHz (will require a new hard-drive and image, so this will be a little work, but looks like a good machine).? Currently on bid and will probably go for 4K or less.
3)??Agilent E5061A going for $2300.? Only goes up to 1.5 GHz, but if that's all you need then a reasonable option.
A note of warning:? All of these new machines should be considerably faster with similar or perhaps even better dynamic ranges BUT they use early versions of windows.? You cannot put these on your network for security reasons as they're completely prone to viruses and other attacks.? They boot terribly slow (relative to your HP8753 or any recent machine), but once they're up and running they should be much faster for running your actual tests.
I have repaired only a single Agilent machine - an N5230A PNA.? Plenty fast, but also boots slow.
The normal disclaimers:? do your own research before you buy, look for buyers who accept returns, don't buy anything that you can't fix, etc.
Good luck!
|
Re: HP 8640B Attenuator Repair
On Wed, Nov 29, 2023 at 09:31 PM, Don Brown, N3DEB wrote:
he acrylic cams inside the attenuator found some were cracking. Applied proper "Weld-On #3" acrylic cement with applicator needle to each cracked cam. (On another unit I drove the cams off the s
Pictures would be amazing if you have any.?
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Thanks Yves, I will put in a new battery and see how it goes. I am thinking of a rechargeable Li-Ion mounted on the rear panel with the wiring going to the board, ? ? ? ? ? ? ? ? ? ? ? ? ? ?Regards Brad?
Hi, ???Here is the clip and service manual for the 8590A series. ? ? Regards Yves ? ? I am in the process of repairing a HP8591A spectrum analyser which seems to have a control fault. Apparently the previous owner tried to replace the control board battery, and now the instrument has a control problem. I can get it to work by going into the config menu and resetting the config, when the green Preset button is pressed, it goes into a and less control loop that causes the display to 'jitter'. Can anyone point me to the CLIP and troubleshooting manual? ? ? ? ? ? ? ? ? ? Regards Brad?
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Jared Cabot
KB2LMN
vk2bea