Products > Test Equipment
Anritsu MS4630B 10Hz-300MHz network analyser teardown/repair/review
<< < (5/7) > >>
edavid:

--- Quote from: MasterTech on November 02, 2016, 07:22:20 pm ---Nice equipment.
Is there anything similar from other brands? I'm looking for something that can measure phase and freq response of a DUT from nearly dc to some 10-100MHz.

--- End quote ---

HP 3577A or HP 3589A network analyzer

HP 3575A gain/phase meter
PartialDischarge:
You just made my day edavid. What a beauty that 3575A, old style HP, no software updates or EMI crap problems. I may get one just for the fun of it
TurboTom:
I've got an inquiry to all the MS4630B owners/users:

We've recently acquired such a machine at work (basically for playing around a little...) but stumbled quickly into some strange behavior:

It actually seems to be a software bug which may be related to an early software revision on our analyzer. What we basically found was a strange behavior of our DUT's delay which should be fairly constant over the frequency. We narrowed the problem down to a comparison of two BNC cables of different lenght (a 0.5m one from out B to the R(eference) input and a 2m one from the second out B to the T(est)A input). If we set up the machine to measure magnitude and delay while the frequency axis is linear, everything's fine and we see the delay difference as a flat line, offset by the delay of the electrical length difference of the two cables.

As soon as we change the frequency axis to logarithmic, the delay is no longer a flat line but keeps on increasing to the edge of the window. Please see attached photos for the setup and the findings (sorry for the poor quality, bad lighting conditions, cell phone cam and a somewhat tired display backlight...).

What I would like to know is if other machines behave the same way or if this bug had been fixed in a later software revision. Does anybody know if there's a firmware update available and if the firmware could be user-updated at all? Does anyone know of a service manual for these analyzers?

Thanks and all the best,
Thomas
nctnico:
I did some tests on mine (which seems to have slightly newer firmware). I think you can't measure delay like this. You have to remember that everything this machine measures is based on phase and amplitude. At 10kHz the phase difference caused by a 2m long piece of coax is extremely small.
1design:
I would guess what you see is the difference in behaviour of the two cables. Since you did not calibrate the unit and it compares the two inputs, it shows the difference in behaviour of the two cables, which in this case is frequency dependent.

Also, when you change the scale to logarithmic you zoom into the upper decade, magnifying the portion of the spectrum that has the transient behaviour typical of low pass filters(cables). In the linear scale that is probably  just a few pixels on the edge of the screen, try to re-scale it in linear mode.
Navigation
Message Index
Next page
Previous page
There was an error while thanking
Thanking...

Go to full version
Powered by SMFPacks Advanced Attachments Uploader Mod