Re: Scoping the Power Rails [8566B]
@Ozan
Yes, I did mention further up the thread about that which I guess you must have missed. PLL lights 1 and 3 are ON, but I can't see a LED for PLL2.
|
Re: HP-8753E S11 Intermittent Results - Switch or Bridge?
Hi Lothar:
It just started failing Port 1 Test. I was doing this just as this email came in. It is failing it consistently. I do not have a power meter, but I can take a look with my Spectrum Analyzer to see if there are power fluctuations at 3GHz. This problem seems to focus at frequencies higher than 3GHz.?
Once I have a look at the output power, I will open and have a look. This is a new problem, as I never saw this before.
Rich
On Saturday, March 5, 2022, 06:38:56 PM EST, Lothar baier <lothar@...> wrote:
If the S11response changes when you switch back and forth than this would point towards a repeatability issue with the solid state switch the fact that this changes with temperature would also point towards this direction , so here are
a few things to try :
?
- Connect a short to port 1 ,? go to the service menu there is a op check for port 1 and 2 , run the op check several time first for port 1 then port 2 then go back to port 1 and so
on , see if it passes consistently or if there is a failure
- If you have a power meter connect it to port 1 , change the analyzer to CW and a frequency close to the upper end (3 or 6GHz), set power to 0dBm and then switch back and forth between
S11 and S22 measurement and see if the power changes
- Open the unit and check the hardline connetions , make sure the nuts are tight
?
Sent from for Windows
?
From: Rich Miller via groups.io
Sent: Saturday, March 5, 2022 5:24 PM
To: HP-Agilent-Keysight-equipment
Subject: [HP-Agilent-Keysight-equipment] HP-8753E S11 Intermittent Results - Switch or Bridge?
I have an issue with S11 (Port 1). It showed it's head now that I am running two port calibrations, thus I have not detected it just yet. My hunch is I have
a problem with the switch, but not the Bridge. Here is what I am observing:
1. Upon boot up I get a good/normal S11 RL Response into a good 50 Ohm Load. This Condition will persist until I do one of the steps below.
2. If I switch to Port 2 (i.e. S22 Measurement), and then back to Port 1 the S11 Response has gone nutty (See Attached Picture).?
3. I have noticed, that if I depress the S11 MEAS multiple times, the S11 RL Response returns to normal.?
4. If you look at the enclosed picture, I have captured what I refer to as a normal S11 response, which I saved to memory (Smooth), and what it looks like after
pressing S11 again (Wild variations in response).
I have noticed there is a stark difference between instrument, cold and warm on S11. I do not however see this behavior our of any of the Port 2 Measurements
regardless of temperature. Is there anywhere else this could be coming from other than the Solid State Switch, or am I way off base in my thinking here??
|
Re: HP-8753E S11 Intermittent Results - Switch or Bridge?
If the S11response changes when you switch back and forth than this would point towards a repeatability issue with the solid state switch the fact that this changes with temperature would also point towards this direction , so here are
a few things to try :
?
- Connect a short to port 1 ,? go to the service menu there is a op check for port 1 and 2 , run the op check several time first for port 1 then port 2 then go back to port 1 and so
on , see if it passes consistently or if there is a failure
- If you have a power meter connect it to port 1 , change the analyzer to CW and a frequency close to the upper end (3 or 6GHz), set power to 0dBm and then switch back and forth between
S11 and S22 measurement and see if the power changes
- Open the unit and check the hardline connetions , make sure the nuts are tight
?
Sent from for Windows
?
toggle quoted message
Show quoted text
From: Rich Miller via groups.io
Sent: Saturday, March 5, 2022 5:24 PM
To: HP-Agilent-Keysight-equipment
Subject: [HP-Agilent-Keysight-equipment] HP-8753E S11 Intermittent Results - Switch or Bridge?
?
I have an issue with S11 (Port 1). It showed it's head now that I am running two port calibrations, thus I have not detected it just yet. My hunch is I have
a problem with the switch, but not the Bridge. Here is what I am observing:
1. Upon boot up I get a good/normal S11 RL Response into a good 50 Ohm Load. This Condition will persist until I do one of the steps below.
2. If I switch to Port 2 (i.e. S22 Measurement), and then back to Port 1 the S11 Response has gone nutty (See Attached Picture).?
3. I have noticed, that if I depress the S11 MEAS multiple times, the S11 RL Response returns to normal.?
4. If you look at the enclosed picture, I have captured what I refer to as a normal S11 response, which I saved to memory (Smooth), and what it looks like after
pressing S11 again (Wild variations in response).
I have noticed there is a stark difference between instrument, cold and warm on S11. I do not however see this behavior our of any of the Port 2 Measurements
regardless of temperature. Is there anywhere else this could be coming from other than the Solid State Switch, or am I way off base in my thinking here??
|
HP-8753E S11 Intermittent Results - Switch or Bridge?
I have an issue with S11 (Port 1). It showed it's head now that I am running two port calibrations, thus I have not detected it just yet. My hunch is I have a problem with the switch, but not the Bridge. Here is what I am observing:
1. Upon boot up I get a good/normal S11 RL Response into a good 50 Ohm Load. This Condition will persist until I do one of the steps below.
2. If I switch to Port 2 (i.e. S22 Measurement), and then back to Port 1 the S11 Response has gone nutty (See Attached Picture).?
3. I have noticed, that if I depress the S11 MEAS multiple times, the S11 RL Response returns to normal.?
4. If you look at the enclosed picture, I have captured what I refer to as a normal S11 response, which I saved to memory (Smooth), and what it looks like after pressing S11 again (Wild variations in response).
I have noticed there is a stark difference between instrument, cold and warm on S11. I do not however see this behavior our of any of the Port 2 Measurements regardless of temperature. Is there anywhere else this could be coming from other than the Solid State Switch, or am I way off base in my thinking here??
Rich?
|
Re: Scoping the Power Rails [8566B]
Didn't Albert Einstein say something like Everything should be made as simple as possible? but no simpler.? I always figured he was making a joke.
Jim
Sent from my T-Mobile 4G LTE Device
toggle quoted message
Show quoted text
-------- Original message -------- From: Tom Lee <tomlee@...> Date: 3/5/22 2:52 PM (GMT-08:00) Subject: Re: [HP-Agilent-Keysight-equipment] Scoping the Power Rails [8566B]
Probably the easiest way to explain it is that harmonic distortion
makes every cycle look the same. Distorted, but the same. So the
time between zero-crossings doesn't move around in that case.
-- Cheers,
Tom
--
Prof. Thomas H. Lee
Allen Ctr., Rm. 205
350 Jane Stanford Way
Stanford University
Stanford, CA 94305-4070
On 3/5/2022 14:43, Jim Ford wrote:
Yeah, it didn't sit quite right with me, either,
distortion creating phase noise.? But I don't have the academic
chops to explain it like you, Tom.? Thanks for weighing in.?
Jim Ford
Sent from
my T-Mobile 4G LTE Device
-------- Original message --------
Date: 3/5/22 2:21 PM (GMT-08:00)
Subject: Re: [HP-Agilent-Keysight-equipment] Scoping the
Power Rails [8566B]
Actually, not quite. Harmonic distortion does not generate phase
noise (the integer relation of harmonics means that the
zero-crossings do not undergo modulations). You need extra (and
somewhat special) ingredients for distortions to produce phase
noise.
Cheers,
Tom
--
Prof. Thomas H. Lee
Allen Ctr., Rm. 205
350 Jane Stanford Way
Stanford University
Stanford, CA 94305-4070
On 3/5/2022 13:14, Jinxie wrote:
Thanks, Matt. I wouldn't have thought it
would make enough difference either - BUT I guess any distortion
of a pure sine wave generates phase noise which isn't exactly
going to help, so who knows?
|
Re: Scoping the Power Rails [8566B]
On Sat, Mar 5, 2022 at 03:05 PM, Jinxie wrote:
Ozan, your A10 02 LED doesn't seem to be lit from what I can see.
I take all your other points on board.
------- It is a miracle that any of the LEDs are lighting up on my unit based on the condition I found it. The reason for attaching the picture was to remind you the question asked earlier about whether any lock LEDs are lighting up on your unit.? Ozan
|
Re: Scoping the Power Rails [8566B]
Makes perfect sense, Tom!? I wish all my professors had made it that simple, 30+ years ago!? Thanks.
Jim?
Sent from my T-Mobile 4G LTE Device
toggle quoted message
Show quoted text
-------- Original message -------- From: Tom Lee <tomlee@...> Date: 3/5/22 2:52 PM (GMT-08:00) Subject: Re: [HP-Agilent-Keysight-equipment] Scoping the Power Rails [8566B]
Probably the easiest way to explain it is that harmonic distortion
makes every cycle look the same. Distorted, but the same. So the
time between zero-crossings doesn't move around in that case.
-- Cheers,
Tom
--
Prof. Thomas H. Lee
Allen Ctr., Rm. 205
350 Jane Stanford Way
Stanford University
Stanford, CA 94305-4070
On 3/5/2022 14:43, Jim Ford wrote:
Yeah, it didn't sit quite right with me, either,
distortion creating phase noise.? But I don't have the academic
chops to explain it like you, Tom.? Thanks for weighing in.?
Jim Ford
Sent from
my T-Mobile 4G LTE Device
-------- Original message --------
Date: 3/5/22 2:21 PM (GMT-08:00)
Subject: Re: [HP-Agilent-Keysight-equipment] Scoping the
Power Rails [8566B]
Actually, not quite. Harmonic distortion does not generate phase
noise (the integer relation of harmonics means that the
zero-crossings do not undergo modulations). You need extra (and
somewhat special) ingredients for distortions to produce phase
noise.
Cheers,
Tom
--
Prof. Thomas H. Lee
Allen Ctr., Rm. 205
350 Jane Stanford Way
Stanford University
Stanford, CA 94305-4070
On 3/5/2022 13:14, Jinxie wrote:
Thanks, Matt. I wouldn't have thought it
would make enough difference either - BUT I guess any distortion
of a pure sine wave generates phase noise which isn't exactly
going to help, so who knows?
|
Re: Scoping the Power Rails [8566B]
Ozan, your A10 02 LED doesn't seem to be lit from what I can see.
I take all your other points on board.
|
Re: Scoping the Power Rails [8566B]
On Sat, Mar 5, 2022 at 02:32 PM, Jinxie wrote:
@Ozan
That is a very valid observation if indeed the wave is digitised further down the line. However, whilst that would certainly work fine as-is for digital purposes, is it realistic to suppose that a company like HP, with all its attention to detail, would allow a VCXO into production that produced a dirty signal like this? Is it not more likely that this distortion might be indicative of some underlying issue elsewhere which could be fundamentally related to the YTO unlock error?
--- Hi Jinxie, Could you put screenshot of the waveform in a photo folder, or attach to the posts if the image is not large? Also note how you are measuring (50-ohm terminated, with a scope probe etc). What may look like a bad signal to you could be OK for its purpose. Perhaps one of the group members can compare with their 8566B. I do have RF section of an 8566B bought for parts but I don't know if my reference generator works.? At a high level: A7A1 has its own lock signal which can tell you if there is an issue in that area. Are you sure reference section has an issue? Do you have 100MHz counter to measure the 100MHz output? As Bruce said there are lock indicators on M/N block. I attached the picture on mine that shows green LED for lock. I believe different PLLs lock at different spans but as I wrote above I don't have a way to exercise them (yet).? Ozan
|
Re: Scoping the Power Rails [8566B]
Probably the easiest way to explain it is that harmonic distortion
makes every cycle look the same. Distorted, but the same. So the
time between zero-crossings doesn't move around in that case.
-- Cheers,
Tom
--
Prof. Thomas H. Lee
Allen Ctr., Rm. 205
350 Jane Stanford Way
Stanford University
Stanford, CA 94305-4070
On 3/5/2022 14:43, Jim Ford wrote:
toggle quoted message
Show quoted text
Yeah, it didn't sit quite right with me, either,
distortion creating phase noise.? But I don't have the academic
chops to explain it like you, Tom.? Thanks for weighing in.?
Jim Ford
Sent from
my T-Mobile 4G LTE Device
-------- Original message --------
Date: 3/5/22 2:21 PM (GMT-08:00)
Subject: Re: [HP-Agilent-Keysight-equipment] Scoping the
Power Rails [8566B]
Actually, not quite. Harmonic distortion does not generate phase
noise (the integer relation of harmonics means that the
zero-crossings do not undergo modulations). You need extra (and
somewhat special) ingredients for distortions to produce phase
noise.
Cheers,
Tom
--
Prof. Thomas H. Lee
Allen Ctr., Rm. 205
350 Jane Stanford Way
Stanford University
Stanford, CA 94305-4070
On 3/5/2022 13:14, Jinxie wrote:
Thanks, Matt. I wouldn't have thought it
would make enough difference either - BUT I guess any distortion
of a pure sine wave generates phase noise which isn't exactly
going to help, so who knows?
|
Re: Scoping the Power Rails [8566B]
Yeah, it didn't sit quite right with me, either, distortion creating phase noise.? But I don't have the academic chops to explain it like you, Tom.? Thanks for weighing in.?
Jim Ford
Sent from my T-Mobile 4G LTE Device
toggle quoted message
Show quoted text
-------- Original message -------- From: Tom Lee <tomlee@...> Date: 3/5/22 2:21 PM (GMT-08:00) Subject: Re: [HP-Agilent-Keysight-equipment] Scoping the Power Rails [8566B]
Actually, not quite. Harmonic distortion does not generate phase
noise (the integer relation of harmonics means that the
zero-crossings do not undergo modulations). You need extra (and
somewhat special) ingredients for distortions to produce phase
noise.
Cheers,
Tom
--
Prof. Thomas H. Lee
Allen Ctr., Rm. 205
350 Jane Stanford Way
Stanford University
Stanford, CA 94305-4070
On 3/5/2022 13:14, Jinxie wrote:
Thanks, Matt. I wouldn't have thought it would make enough
difference either - BUT I guess any distortion of a pure sine wave
generates phase noise which isn't exactly going to help, so who
knows?
|
Re: Scoping the Power Rails [8566B]
@Ozan
That is a very valid observation if indeed the wave is digitised further down the line. However, whilst that would certainly work fine as-is for digital purposes, is it realistic to suppose that a company like HP, with all its attention to detail, would allow a VCXO into production that produced a dirty signal like this? Is it not more likely that this distortion might be indicative of some underlying issue elsewhere which could be fundamentally related to the YTO unlock error?
|
Re: Scoping the Power Rails [8566B]
You're right, Tom. Strictly speaking I believe it's random jitter of a pure sine that gives rise to phase noise. But I'm no expert in this area!
|
Re: Scoping the Power Rails [8566B]
Actually, not quite. Harmonic distortion does not generate phase
noise (the integer relation of harmonics means that the
zero-crossings do not undergo modulations). You need extra (and
somewhat special) ingredients for distortions to produce phase
noise.
Cheers,
Tom
--
Prof. Thomas H. Lee
Allen Ctr., Rm. 205
350 Jane Stanford Way
Stanford University
Stanford, CA 94305-4070
On 3/5/2022 13:14, Jinxie wrote:
toggle quoted message
Show quoted text
Thanks, Matt. I wouldn't have thought it would make enough
difference either - BUT I guess any distortion of a pure sine wave
generates phase noise which isn't exactly going to help, so who
knows?
|
Re: Scoping the Power Rails [8566B]
On Sat, Mar 5, 2022 at 01:14 PM, Jinxie wrote:
Thanks, Matt. I wouldn't have thought it would make enough difference either - BUT I guess any distortion of a pure sine wave generates phase noise which isn't exactly going to help, so who knows?
------ First thing reference signal hits in the PLL (A7A1) is a comparator, followed by logic gates. It is fine if the reference is not sine-wave looking. It will be converted to a logic levels anyway.? Ozan
|
Re: 8341B Issues 1992 firmware
Luckily both sweepers still have the paper with the cal constants inside the unit so changing them will be easy
toggle quoted message
Show quoted text
On Mar 5, 2022, at 14:52, Bruce via groups.io <bruce@...> wrote:
?All you need to do to adapt the 40 CPU to the 41 is to change one of the cal constants so the top freq is 20 instead of 26.5 - I forget which one, but it is listed in the documentation
Cheers!
Bruce
Quoting Lothar baier <Lothar@...>:
I aint getting this fancy in my old days:) the main purpose of this was to update the 8341B to work with the 8516A , i will just swap the CPU boards between the 40 and 41 that frees up the 40 as general lab signal generator
On Mar 5, 2022, at 14:21, Bruce via groups.io <bruce@...> wrote: ?I believe there are signature analysis routines that could help debugging it.
Cheers!
Bruce
Quoting Lothar baier <Lothar@...>:
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 Mail<> for Windows
From: Bruce via groups.io<mailto:bruce@...>
Sent: Saturday, March 5, 2022 11:19 AM
To: [email protected]<mailto:[email protected]>
Subject: Re: [HP-Agilent-Keysight-equipment] 8341B Issues 1992 firmware
Hopefully you can return the CPU to the seller !
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#)
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 Mail<> 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: Scoping the Power Rails [8566B]
A thing to remember is that distortions in the 10MHz OUT could be related to the fact that the 100 MHz ref oscillator is not phase locked. Cheers! Bruce Quoting Jinxie <paul666@...>:
Thanks, Matt. I wouldn't have thought it would make enough difference either - BUT I guess any distortion of a pure sine wave generates phase noise which isn't exactly going to help, so who knows?
|
Re: Scoping the Power Rails [8566B]
Thanks, Matt. I wouldn't have thought it would make enough difference either - BUT I guess any distortion of a pure sine wave generates phase noise which isn't exactly going to help, so who knows?
|
Re: Scoping the Power Rails [8566B]
That may actually be ok. The divided VCXO signal used to phase lock
the VCXO to the reference may not need to be a good sine wave, though
I'm not sure. If someone who understands the operation of this PLL
better than me wants to chime in, please do. If I get a few minutes
later I'll run the same test on my working 8566B and will share the
results for comparison.
Matt
toggle quoted message
Show quoted text
On Sat, Mar 5, 2022 at 11:39 AM Jinxie <paul666@...> wrote:
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
All you need to do to adapt the 40 CPU to the 41 is to change one of the cal constants so the top freq is 20 instead of 26.5 - I forget which one, but it is listed in the documentation
Cheers!
Bruce
Quoting Lothar baier <Lothar@...>:
toggle quoted message
Show quoted text
I aint getting this fancy in my old days:) the main purpose of this was to update the 8341B to work with the 8516A , i will just swap the CPU boards between the 40 and 41 that frees up the 40 as general lab signal generator
On Mar 5, 2022, at 14:21, Bruce via groups.io <bruce@...> wrote:
?I believe there are signature analysis routines that could help debugging it.
Cheers!
Bruce
Quoting Lothar baier <Lothar@...>:
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 Mail<> for Windows
From: Bruce via groups.io<mailto:bruce@...>
Sent: Saturday, March 5, 2022 11:19 AM
To: [email protected]<mailto:[email protected]>
Subject: Re: [HP-Agilent-Keysight-equipment] 8341B Issues 1992 firmware
Hopefully you can return the CPU to the seller !
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#)
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 Mail<> 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 ?
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Jinxie
