OK - then ther should be no DC "roll off"

Cheers!

Bruce

Quoting Dave Wright <davewrightsplace@...>:

The 8471A is DC coupled.
The input termination resistor is connected between the diode anode and case.
The output capacitor is connected between the diode cathode and the case.


_Dave

Here's the response I got from Keysight today:

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?

If the oscilloscope has any of the following symptoms, it may qualify for a free repair under our internal Service Note DSOX2014A-06B:

• It powers up but the screen remains blank and the keyboard LEDs begin to flash in sequence
• Its splash screen is displayed with cycling keyboard LEDs
• It continually reboots
• The boot halts with any combination of the Serial, Digital, Math or Ref LEDs remaining lit

In this case, you can contact our service center at the following number and request an evaluation for the free repair:

800-829-4444 (Press 3, then 1)

If/when you call, please be sure to mention the Service Note and be as detailed as possible about the behavior you’re seeing.? If your description does not match one of the four failure modes listed above, you will be charged for the evaluation.? The evaluation fee would only be refunded if our repair technician confirms the failure is covered under the service note.

Before sending the unit in, you may want to try solving the problem on your own.? This would require updating the firmware, which is only possible if you can get the unit to boot properly one time.? I would recommend making at least 10 or 20 attempts (i.e., power cycles), although some users have reported success after as many as 100 attempts.? If it boots normally just once, you should immediately install the latest 2.65 firmware before turning it off.? You’ll find the download and installation instructions for the update here:

The new firmware would permanently solve the problem, and the unit would not need repair.

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Looks like there's an internal service note that addresses this very issue. I know my scope meets the criteria of the service note. We'll see what Keysight has to say about qualifying for a free repair. As soon as I get an RMA number I'll be sending it in.

Thanks to all who responded, and I'll keep the group posted on my progress!

Stan

No i dont have disk ..ill post pics soon , maybe yes i dont know much about 54712A

here the pics..

Is the detector DC coupled or is there a blocking cap ?

Cheers!

Bruce


Quoting Dave Wright <davewrightsplace@...>:

The HP 8471A OEM diode is 1N831, and there are some on eBay. I have two on the way now.

Left to right in the photo is the input termination resistor, 50 Ohms, some sort of film deposited on the disk between the BNC male center pin and a contact ring to the case. The diode anode lead is soldered directly into the input center pin at 'zero length'. ?The cathode lead passes through the center of a disk capacitor, measured as ~1500pf, and on to the center pin of the output BNC female.?

The assembly process will require care in soldering, I imagine it will go as: input R first, then output C, then screw gold plated center into the BNC male body, solder BNC female center pin to protruding cathode lead, and thread main body over all.

Intend to measure performance on 8753D VNA when completed.

More as it happens...

Arkadiusz Gibes? , I own the trigger you mention look very similar to the calibrator but has no eprom inside my plan was to modi the

Hello dear members,

I got a HP3580A in good working order, but having one problem.
On the back side is an adjustment knob to set the output level of the tracking oscillator.
The axis of this potmeter is broken ( and missing knob of course) so this part has to be replaced.
Removing the lower cover should give me acces to this potmeter i hoped, but nope.
Does anyone know how to dismantle the analyser in order to gain acces to this part?
I have a copy of the operating & service manual but could not find any exploded vieuw.
any help is welcome.

Many thank .
Herman,
The Netherlands

--
Ken H.

开云体育

Much depends on how the equipment was designed.? For a scope, you could need a controlled square or sine wave source, various amplitudes and various frequencies.? Often it needs to have a particular command set and a controller (computer) to automate the tests.? Often, the tests are not specified, simply programmed.? The code source is not always documented.? All of this is true if and when the code is even available.

It can get nasty.

It also, as you note, depends on which set of constants you need to regenerate.?

Not all calibration procedures are documented to the extent you can perform them, even if you had the equipment.

Harvey

--
Ken H.
If you provide the serial number, I can check.?

Hi Nicolas,

I can report from my calibration experience with an HP8593E. I assume there is no big difference in procedures to your HP8594E.
I purchased a used HP8593E to find that is was only calibrated to 18GHz. For the frequency range 18...27GHz there were no correction coefficients, so level readings were way off.

Calibration required a stable generator for the frequency range in question, a high quality splitter and an accurate power meter. You have to take a level measurement with the SA at every single correction grid frequency (there are many!) and write it down. You find those lists in the manual.
Then you have to enter all those numbers point by point into the instrument. I used the front panel keys to do that.
This may be automated via GPIB, but you still need to get the numbers into a computer.
It was very tedious and I refrained from re-calibrating the range below 18GHz. I do not ever want to do this again.
That's why in the same pass I replaced the CMOS memory battery. Now, I should be safe for another 10 years.

Best regards,
Tom

Sorry:
maurinot (AT) libero (DOT) it?

Hi Stan,
as Phil says, if Keysight does not guarantee you will need to do it yourself, you will need a LAN card for your DSOX2024.
If you want, I still have some LAN cards available.
You can see them on eBay by searching for:? "Agilent Keysight DSOXLAN Card MSOX DSOX 2000 3000 InfiniiVision Oscilloscope"
Otherwise with, a little discount (45Eu. + Sp.), send me a PM to maurinot (AT) libero (DOT)?
Have a good day.
maurizio - Italy