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Re: Scoping the Power Rails [8566B]
Squeezed it in unseen. ;-)
On RF OUT now it's showing 10.00000Mhz but the waveform on the scope (using 50 ohm 350Mhz analogue Tek scope this time) is not pure sine. The positive peaks are definitely sharper than the negative ones. I've seen that kind of distortion before but can't recall what causes it. Not sure if it's relevant to the issue, but certainly not up to required standard. :( |
Re: 8341B Issues 1992 firmware
Lothar baier
开云体育Fixing to do that ! I only paid $75 for the board and since the FW proms are ok I am almost tempted to keep it for the chips ? Sent from for Windows ? From: Bruce via groups.io
Sent: Saturday, March 5, 2022 11:19 AM To: [email protected] Subject: Re: [HP-Agilent-Keysight-equipment] 8341B Issues 1992 firmware ? Hopefully you can return the CPU to the seller ! ? |
Re: HP200CD oscillator
Bob Albert
Part of the problem was that the cathode of a selenium rectifier was marked with a + sign to signify that it was the positive output of the rectifier system.? Of course that was the cathode.? So many people, including me, got confused.? Later, things got more reasonable and all was good.? But in the interim there was a lot of mistakes made in diagrams and, unfortunately, in construction. Bob
On Saturday, March 5, 2022, 08:01:48 AM PST, <n8zmtwh@...> wrote:
If you were familiar with them, it might have been tougher to make that mistake, but I recall a lot of confusion when solid state rectifiers first came out about which way they were to go in a circuit where they were replacing tubes. And it wasn’t just me! ? From: [email protected] <[email protected]> On Behalf Of Jim Adney
Sent: Saturday, March 05, 2022 10:55 AM To: [email protected] Subject: Re: [HP-Agilent-Keysight-equipment] HP200CD oscillator ? On Sat, Mar 5, 2022 at 12:31 AM, Tom Lee wrote:
It would be a lot harder to make that mistake with a hollow state rectifier.? ;-) |
Re: 8341B Issues 1992 firmware
Hopefully you can return the CPU to the seller !
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While you were at it, did you try the 8510/8516 using the CPU from the lab in your 8341??? Cheers! Bruce Quoting Lothar baier <Lothar@...>: Yes the lab 8340B does have the new CPU board ( same part#) |
Re: Scoping the Power Rails [8566B]
Thanks, Matt. I think you may be right as it would explain a lot if it were just a case of component value drift over time needing correction.
I may be able to squeeze in a fresh test on the 10Mhz OUT in a couple of hours from now if I can sneak away from the family unnoticed. Laterz.... |
Re: Scoping the Power Rails [8566B]
Good, so it sounds like your reference is fine. I would redo the test
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on the 10 MHz OUT next. If you still see that harmonic, it will narrow down at least one of the problems with this unit. If not, we'll need to look elsewhere. It's still too early to tell, but it's entirely possible there's nothing actually wrong with this unit. It could just be that it's a bit out of tune. As I already mentioned, this exact thing has happened to me twice on units with all working parts. Matt On Sat, Mar 5, 2022 at 8:41 AM Jinxie <paul666@...> wrote:
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Re: Scoping the Power Rails [8566B]
Okay, now re-done. I was having issues with a dodgy patch-lead which I've now replaced with a known good one. Attaching direct to "INT" this time, with the switch still set to "INT" I'm seeing 10Mhz stable on the frequency counter and? what looks to be a pure sine wave of about 1.2V P-P on the 50 ohm scope input. Can't fault that IMHO.
My scope for carrying out any more tests this evening is very limited, but I'll have a lot more time tomorrow if anyone has any follow-up tests I should try. I don't think there's any point now in injecting an ext. 10Mhz in the light of the foregoing, quite honestly, since unless that signal level is too low, it should do the job I'd have thought. |
Re: 8341B Issues 1992 firmware
Lothar baier
开云体育Yes the lab 8340B does have the new CPU board ( same part#) So I opened the lid and swapped CPU boards , my 8341B works ok with the CPU board from the 8340B except the top frequency is 26GHz ,? the 8340B however shows the same issue as the 8341 if I plug in the CPU board I bought so I think its safe to say the board has a problem ? Sent from for Windows ? From: [email protected] <[email protected]> on behalf of Bruce via groups.io <bruce@...>
Sent: Saturday, March 5, 2022 10:05:13 AM To: [email protected] <[email protected]> Subject: Re: [HP-Agilent-Keysight-equipment] 8341B Issues 1992 firmware ?
Does the "lab" 8340B have the same CPU board as your "new" CPU?? If?
not, how can putting the 92 FW on that board resolve anything? Are the PALS on the new CPU the same as the PALS on the old CPU Cheers! Bruce Quoting Lothar baier <Lothar@...>: > The board goes through the regular cycle when powered up the only? > difference is that the frequencies the unit comes up with are? > screwed up ! > The problem is that I don’t have any evidence that the firmware on? > the new board is functional , I bought the board on ebay from global? > test as used and I don’t know if they checked it or how long ago it? > was checked before going into stock . > I have a 8340B in the lab that has the correct serial number range? > and a 88 FW so as last resort I could pop the lid and pop the 92 FW? > chips in this unit to see if it works > > > Sent from Mail<> for Windows > > From: Bruce via groups.io<mailto:bruce@...> > Sent: Saturday, March 5, 2022 9:40 AM > To:? > [email protected]<mailto:[email protected]> > Subject: Re: [HP-Agilent-Keysight-equipment] 8341B Issues 1992 firmware > > When you had the new board running the newer software were any of the > CPU LEDs lit ?? What evidence do you have that the firmware on the new > CPU is functional? (This is a long shot as I believe the CPU checks > the check sum of the FW) > > Cheers! > > Bruce > Quoting Lothar baier <Lothar@...>: > >> Well i looked at the manual backdating and the only 2 boards that >> change between 2804 and 2812 Are the CPU board and the sweep board >> no mention of changes to the motherboard or other boards . >> I updated the cal constants >>> On Mar 4, 2022, at 23:43, Bruce via groups.io >>> <bruce@...> wrote: >>> >>> ?Couple of things to think about: >>> 1) Is the motherboard the same between the 2804 and 2812 ? >>> 2) What about the PALs on the CPU board >>> 3) Also check that the CAL constand definitions are the same >>> between the versions. >>> >>> Cheers! >>> >>> Bruce >>> >>> >>> >>> Quoting Lothar baier <Lothar@...>: >>> >>>> i am banging my head right now which doesnt happen all too often >>>> so maybe somebody here has experienced a similar issue : >>>> i have a 8341B Sweeper ,? the serial# is 2804A and the FW Date is >>>> 1982 ,? i am trying to use this sweeper with a 8516A which >>>> requires a higher FW revision (May 88)? and also a SN 2812A or >>>> higher . >>>> i looked up the changes between 2804 and 2812 and only the CPU >>>> board and the sweep board changed so i went on ebay and found a >>>> CPU board that already had 1992 firmware installed from a dealer i >>>> consider reputable . >>>> The board came in and i installed it in my 8341B tonight , after >>>> hitting preset the unit comes up with a start frequency of 100MHz >>>> and stop of 200GHz , overmod indicator and unleveled blinking , >>>> unit accepts frequency entries but nothing lower than 100MHz . >>>> So i accessed the calibration contants and updated them using the >>>> ones from the old board , overmod goes away but unleveled is still >>>> blinking and still no lower than 100MHz . >>>> Next i took out the FW EPROMS and put them in the old CPU Board >>>> just to experience the same issues , now i took the old FW Eproms >>>> and plugged them in the new CPU board and things work fine so the >>>> CPU board seems to be fine so the problem seems to be with the FW >>>> Eproms , unfortunatly i no longer have a EPROM programmer so i >>>> cant download the image and burn new EPROMS . >>>> Question here is now has somebody here installed or tried to >>>> install 1992 firmware on a 8340 or 41 and run into the same >>>> problems and if so what was the resolution ? >>>> >>>> >>> >>> >>> >>> >>> >>> >>> >>> >> >> >> > > > > > > > > > > > |
Re: 8341B Issues 1992 firmware
Does the "lab" 8340B have the same CPU board as your "new" CPU? If not, how can putting the 92 FW on that board resolve anything?
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Are the PALS on the new CPU the same as the PALS on the old CPU Cheers! Bruce Quoting Lothar baier <Lothar@...>: The board goes through the regular cycle when powered up the only difference is that the frequencies the unit comes up with are screwed up ! |
Re: HP200CD oscillator
开云体育If you were familiar with them, it might have been tougher to make that mistake, but I recall a lot of confusion when solid state rectifiers first came out about which way they were to go in a circuit where they were replacing tubes. And it wasn’t just me! ? From: [email protected] <[email protected]> On Behalf Of Jim Adney
Sent: Saturday, March 05, 2022 10:55 AM To: [email protected] Subject: Re: [HP-Agilent-Keysight-equipment] HP200CD oscillator ? On Sat, Mar 5, 2022 at 12:31 AM, Tom Lee wrote:
It would be a lot harder to make that mistake with a hollow state rectifier.? ;-) |
Re: ESG-3000A LCD replacement
开云体育I obtained a slightly newer than the ESG-3000 ESG about a year ago and the display was dark. When I got into it, the fluorescent lamp was working, but the silvering on the paper backing that reflects much of the light into the actual display had badly flaked off. I replaced it with some aluminum tape, no, not as reflective, but it brought the display back to at least visible. Those early ESG displays were always pretty dim even when new. Probably a good candidate for an LED re-fit. ? I have an 8753ES which had the same problem, fixed the same way. It also had the tiny fuse on the inverter power supply blown. So far the fuse has stayed un-blown. ? ? From: [email protected] <[email protected]> On Behalf Of Lothar baier
Sent: Saturday, March 05, 2022 10:49 AM To: [email protected] Subject: Re: [HP-Agilent-Keysight-equipment] ESG-3000A LCD replacement ? My first question to you would be have you checked the backlighr and backlight inverter on the old LCD ?? also on the replacement panel have you checked if the backlight used is the same kind ? ? Sent from for Windows ? From: Manfred Hund (DL2IAO) via groups.io ? Hello Tom, i do have exactly the same problem, no jumpers on the motherboard and a?DMF-51043NFU-FW1, that will not work. The original MDF-50562NFU-FW has stopped to work, so I need a new LCD. Did you have a solution for the problem already? ? |
Re: 8341B Issues 1992 firmware
Lothar baier
开云体育The board goes through the regular cycle when powered up the only difference is that the frequencies the unit comes up with are screwed up ! The problem is that I don’t have any evidence that the firmware on the new board is functional , I bought the board on ebay from global test as used and I don’t know if they checked it or how long ago it was checked before going into stock . I have a 8340B in the lab that has the correct serial number range and a 88 FW so as last resort I could pop the lid and pop the 92 FW chips in this unit to see if it works ? ? Sent from for Windows ? From: Bruce via groups.io
Sent: Saturday, March 5, 2022 9:40 AM To: [email protected] Subject: Re: [HP-Agilent-Keysight-equipment] 8341B Issues 1992 firmware ? When you had the new board running the newer software were any of the?
? |
Re: ESG-3000A LCD replacement
Lothar baier
开云体育My first question to you would be have you checked the backlighr and backlight inverter on the old LCD ?? also on the replacement panel have you checked if the backlight used is the same kind ? ? Sent from for Windows ? From: Manfred Hund (DL2IAO) via groups.io
Sent: Saturday, March 5, 2022 9:17 AM To: [email protected] Subject: Re: [HP-Agilent-Keysight-equipment] ESG-3000A LCD replacement ? Hello Tom, i do have exactly the same problem, no jumpers on the motherboard and a?DMF-51043NFU-FW1, that will not work. The original MDF-50562NFU-FW has stopped to work, so I need a new LCD. Did you have a solution for the problem already? ? |
Re: ESG-3000A LCD replacement
开云体育Hello Manfred, Good luck. The difference in the FW1 and FW is the polarity of
the contrast bias.? If you put in the FW1 in the older model it
will blow the transistor that supplies the contrast bias.? The
later motherboard has jumpers to set the bias polarity. There is a long thread here where someone replaced the LCD in his ESG, see: Tom Bryan
On 3/5/2022 10:17 AM, Manfred Hund
(DL2IAO) wrote:
Hello Tom, i do have exactly the same problem, no jumpers on the motherboard and a?DMF-51043NFU-FW1, that will not work. The original MDF-50562NFU-FW has stopped to work, so I need a new LCD. Did you have a solution for the problem already? Best regards Manfred |
Re: 8341B Issues 1992 firmware
When you had the new board running the newer software were any of the CPU LEDs lit ? What evidence do you have that the firmware on the new CPU is functional (This is a long shot as I believe the CPU checks the check sum of the FW)
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Show quoted text
Cheers! Bruce Quoting Lothar baier <Lothar@...>: Well i looked at the manual backdating and the only 2 boards that change between 2804 and 2812 Are the CPU board and the sweep board no mention of changes to the motherboard or other boards . |