Re: 5086-7337 *Yig Oscillator issue*
If that test fails (I or V not changing) check the drive V to Q1.
If that is changing but the I does not (or the V across the R), suspect Q1.
Mark
toggle quoted message
Show quoted text
Ruben -
Probably the easiest check is to see if the voltage across the?
resistor changes with frequency.? Somewhere in the service manual,?
they should give you the ma/Hz number for this circuit.? If that works?
out correctly, the YIG drive is OK.? If the current is different than?
specified, the problem is with the YIG drive circuit.? Also, be sure?
you are measuring the main YIG drive and not the FM coil.? Bu be sure?
to check the current in the FM cil as it also can cause problems?
(usually less frequently).
Cheers!
Quoting RubenRubio <rubenrb2019@...>:
> Reading the schematics, I bring you some ideas, correct me if i'm wrong:
>
> - I must measure the voltage drop across R1 (one of the power?
> resistors in the plugin) and that will reveal the current sent to?
> the YO coil, isn't it?
>
> - The black heatsink on A9 board it's always hot. I think it is?
> hotter than it should be, should check Q1 too? Maybe the transistor?
> is shorted and it doesn't send sufficient current to drive the YO.?
> What you think?
>
> Regards,
> Ruben
>
>
>
|
Re: Agilent E3610A Operator Faux Pas or Production Change
The saga of the E3610A bench power supply continues.
Long story short. HP/Agilent broke with tradition and decided to
market a reduced cost power supply. Apparently part of the cost
reduction was eliminating the tapped primary power transformer
and selector switch for selecting the line voltage in use. Ergo,
the E3610A power supply was born. Three variants, one for
100 VAC a second for 115 VAC and a 3rd for 230VAC were
produced. Each voltage rating was assigned an option number.
The units are tagged on the rear with their respective AC
power requirement. A label with check boxes for each of
the available voltages will have a box checked adjacent to
the required voltage.
As previously pointed out by another writer, there are three
different part numbers for ac power transformers used in the
supply. On a lark I gave Keysight's web based part quote
page a whirl. A very polite response was returned and advised
the supply was last supported in 2014 and declared obsolete
in 2019. The message from Keysight stated the part was no
longer available. Thus my plan to buy a 115 VAC primary
transformer to replace the 230 Volt variant fell flat on its
face.
So, it appears I have a few options:
(1) Try to catch a parts unit on e-Bay
(2) Use a voltage converter wall wart or control transformer to
provide the needed 230 from 115.
(3) Add a drop from the 30 Amp 230 Volt service in the room
for the single power supply.
(4) Cannibalize it.
Que Sera
Thanks for all the help from those that provided input.
Chuck
|
Re: 5086-7337 *Yig Oscillator issue*
Ruben -
Probably the easiest check is to see if the voltage across the resistor changes with frequency. Somewhere in the service manual, they should give you the ma/Hz number for this circuit. If that works out correctly, the YIG drive is OK. If the current is different than specified, the problem is with the YIG drive circuit. Also, be sure you are measuring the main YIG drive and not the FM coil. Bu be sure to check the current in the FM cil as it also can cause problems (usually less frequently).
Cheers!
Quoting RubenRubio <rubenrb2019@...>:
toggle quoted message
Show quoted text
Reading the schematics, I bring you some ideas, correct me if i'm wrong:
- I must measure the voltage drop across R1 (one of the power resistors in the plugin) and that will reveal the current sent to the YO coil, isn't it?
- The black heatsink on A9 board it's always hot. I think it is hotter than it should be, should check Q1 too? Maybe the transistor is shorted and it doesn't send sufficient current to drive the YO. What you think?
Regards,
Ruben
|
E8364-60204 CPU Board (PNA N5230A) Boot Loader SW question
I am attempting to fix a PNA CPU board that is bad.? Some years back it was sent to Keysight for repair and we got a quote of something like 18K, so it has just sat around the office for a couple years.? It has the following symptoms on the CPU board on power-up:
1)? The three LEDs (D5, D6, D7) are lit (red)
2)? The other sections of the unit seem to power up and lights start flashing, etc.
3)? The unit does not beep.? The unit does not appear to load any of the SW.? No sign that the bootloader is being loaded or the BIOS.? The hard drive is not read and the hard drive light (visible from the back of the unit) does not come on.
I thought that the NAND memory might be corrupt, so I removed the Agilent SOP40 chip labeled 080-039-0000.? It is an ST 3V flash memory (M50FW080) that holds 1 MB.? I assumed that this would have the boot loader on it.
I requested the Firmware for my unit from Keysight and they were kind enough to provide me with a file of firmware (A.07.50.67) which they informed me was the most current for my unit.? But now I'm confused and stuck.? The firmware file provided is an executable and is 66 MB.? That firmware flash memory that I mentioned is 1 MB.? The disk drive (assuming that I was able to get it to boot from the disk) has a max size of 1.44 MB I think (3.5" floppy).? I assume that there is a different boot loader file which goes on this chip?? Sorry that I'm so ignorant here, but I'm completely lost at this point.? Hoping that someone can give me a little direction/advice.
One other question:? This unit was supposedly plugged in for something like a year prior to it being powered down and not being able to power up again.? There were some bad bootstrap capacitors in the power supply.? Is there any reason to suspect bad capacitors on the main CPU board?? I have an ESR meter (Peak Atlas ESR70), but I assume that one would need to remove the capacitors from the board prior to testing.? Will testing in place risk damage to other components on the board (or simply give me bad readings)?
Thanks,
Scott
|
Re: Looking for Agilent PNA old FW repo?
Have you checked with Keysight?? I recently requested FW for my unit and they provided me with A.07.50.67.? Not what you need, but I assume that they will help you out if you put in a ticket with Keysightcare.
good luck!
Scott
|
Re: 5086-7337 *Yig Oscillator issue*
Reading the schematics, I bring you some ideas, correct me if i'm wrong:
- I must measure the voltage drop across R1 (one of the power resistors in the plugin) and that will reveal the current sent to the YO coil, isn't it?
- The black heatsink on A9 board it's always hot. I think it is hotter than it should be, should check Q1 too? Maybe the transistor is shorted and it doesn't send sufficient current to drive the YO. What you think?
Regards,
Ruben
|
Thank you very much for answer. I guess your board is an extended version of mine : you have 4 solenoids instead of 3 for me (10+20+30db =60) but
do you know what is the 3 legs chip near the 8L05 regulator ? It is stamped C9Z and I have no idea...
|
Re: 8350B *restoration adventure?*
Ruben -
WELL DONE - Amazing work and obviously a lot of work. The 83590 series have some of the highest current draw, so if it works satisfactorily with these it should be good for most if not all plugs. One possible exception might be the plug that drives the mmWave sources, but you can deal with that when (and if) it occurs.
EXCELLENT WORK
Cheers!
Bruce
Quoting RubenRubio <rubenrb2019@...>:
toggle quoted message
Show quoted text
*Great news!
* My 8350B sweeper is now working! Closed with a standard power cord. You can see some of the montage steps in the pics attached to this post.
Finally, I decided to swap the old burnt main transformer with switching power supplies and a little transformer on a tight budget. A real challenge of wiring, space management, mechanical assembly and proper cooling. After a several hours of work, today I've done the different PS adjustments with sucess. The changes include new 230VAC fan (with more CFM), restructured mains wiring, removal of the old big caps to maximize room for the switchers and new RAM battery pack (w NiMH cells).
Without the external feeding, now it's a more comfortable unit to continue the repairing attempt of the 83592A plugin...
Regards,
Ruben
PD: special thanks to Yves Tardif , without your PS data?I could never have done this repair ;)
|
Re: 8350B *restoration adventure?*
Great news!
My 8350B sweeper is now working! Closed with a standard power cord. You can see some of the montage steps in the pics attached to this post.
Finally, I decided to swap the old burnt main transformer with switching power supplies and a little transformer on a tight budget. A real challenge of wiring, space management, mechanical assembly and proper cooling. After a several hours of work, today I've done the different PS adjustments with sucess. The changes include new 230VAC fan (with more CFM), restructured mains wiring, removal of the old big caps to maximize room for the switchers and new RAM battery pack (w NiMH cells).?
Without the external feeding, now it's a more comfortable unit to continue the repairing attempt of the 83592A plugin...
Regards,
Ruben
PD: special thanks to Yves Tardif, without your PS data?I could never have done this repair ;)
|
Re: 50 Ghz step attenuator driver board
|
WELL DONE !
It would have been nice to get better closeup of recovering the contacts after pulling them through, but overall excellent !
Did you note any deformation of the leaves due to pulling the pins through? Did you have much trouble re-engaging the pins?
Thanks!
Cheers!
Bruce
Quoting bagojfalvibagoj@...:
toggle quoted message
Show quoted text
If you guys want to watch me unscrew screws for 30 or so minutes feel free:
(Ignore any awkward background noises, I didn't check the audio. I only recorded this so I know how to put it back together.)
The last clip is debugging with a DMM. Static voltages are ok, but it definitely gets stuck in some abnormal state. The coil gets hot.
I also added a scribble about what I believe the schematic of the control looks like.
|
50 Ghz step attenuator driver board
Hello,? Does anybody have the schematic diagram --and eventually the parts layout --of the latest 24V driver board? fitted in the 60db 50 Ghz step attenuators (the older ones did have the traditional double V mechanical contacts). Thank you. 
|
HP 35670A display questions
What sort of display is used on a 35670A, and did this change to an LCD at some point? Was a CRT ever used? From this post: /g/HP-Agilent-Keysight-equipment/message/78558it seems to have been an ELD display at some point. I ask because having looked at pictures of various units, there seems to be two different displays: one with an orangish text and another that looks more yellow, typically on newer Agilent units. The yellow displays look nicer to my eye. Unfortunately, I couldn't find any information about this in the various manuals. Thanks Matt
|
Re: My 6655 thinks it is a 6653
I don't really know enough about running HP BASIC programs to say for sure, but HT BASIC does look like a promising option to me.
Another option would be to figure out what the program is doing and run the GPIB commands manually. From a quick glance over it, it first defines arrays of data addresses & lengths and different arrays of values for the different models. When copying the array of values to be used, it replaces positions 21 and 32 with the model# selected (e.g: it replaces 6555 with 6655).
For the "initialization" mode it turns on cal mode with "CAL:STATE ON,<passcode>", writes each value to the eeprom with "DIAG:EEPR <address>,<length>,<value>", then turns off the cal mode again with "CAL:STATE OFF".
Hmm, ok. So if I bought something like HT BASIC to run the listed program from pages 66 to 71 that should theoretically fix it then? Just asking for thoughts and input before I go out and just buy that.
|
If you guys want to watch me unscrew screws for 30 or so minutes feel free:
(Ignore any awkward background noises, I didn't check the audio. I only recorded this so I know how to put it back together.)
The last clip is debugging with a DMM. Static voltages are ok, but it definitely gets stuck in some abnormal state. The coil gets hot.
I also added a scribble about what I believe the schematic of the control looks like.
?
|
Well good luck - keep us informed. For more information on proper drive, you could look at the schematic of the DP attenuator driver - or masure what the 8566 does - I believe it is a pulse from the CPU but not certain.
Cheers!
Bruce
Cheers!
Bruce
Quoting bagojfalvibagoj@...:
toggle quoted message
Show quoted text
I ordered a breadboard overnight. Never have one when you need it.
I have a frightening suspicion, which is that this attenuator works perfectly I just couldn't drive it properly. I hope at least I didn't make it worse.
Now I kinda understand what the circuit is doing. Hopefully tomorrow I can check properly.
The original symptom was about 50dB loss on the input in both frequency modes, so that makes it either the connector, cables, the attenuator or the switch.
I took the attenuator out first as I read that is likely to have issues and since I couldn't turn on 40dB attn on it I concluded this is the culprit.
But maybe not...
Rabbit holes rabbit holes everywhere.
|
I ordered a breadboard overnight. Never have one when you need it.
I have a frightening suspicion, which is that this attenuator works perfectly I just couldn't drive it properly. I hope at least I didn't make it worse.
Now I kinda understand what the circuit is doing. Hopefully tomorrow I can check properly.
The original symptom was about 50dB loss on the input in both frequency modes, so that makes it either the connector, cables, the attenuator or the switch.
I took the attenuator out first as I read that is likely to have issues and since I couldn't turn on 40dB attn on it I concluded this is the culprit.
But maybe not...
Rabbit holes rabbit holes everywhere.
|
I think that is correct.
I don't have the problem you do - I bought one of the HP relay drivers and built a small board with a DIP socket, that lets me plug in the attenuator and drive it using the switchwes. The drivers are cheap ($25) but the cables with matching plugs can be a bit harder to find.
Cheers!
Bruce
Quoting bagojfalvibagoj@...:
toggle quoted message
Show quoted text
I'm looking at the board now and other than the ULN2003A drivers, there are 4 D flipflops which makes me wonder if this needs continuous supply in order to retain state correctly.
Since I was turning the psu on and off it might've caused the improper behavior.
|
I'm looking at the board now and other than the ULN2003A drivers, there are 4 D flipflops which makes me wonder if this needs continuous supply in order to retain state correctly.
Since I was turning the psu on and off it might've caused the improper behavior.
|
I already managed to free the leaves. I think I was lucky. They seem ok to me.
I would guess that the magnet is necessary to make the system bi-stable. The shaft sticks to it on one side and stays there until the coil shoots it over to the other side to stick there. The solenoid still should work as a solenoid I believe, but it doesn't look like doing a very good job at that.
|
RubenRubio
