HP/Agilent 53310A Modulation Domain Analyser / Frequency-Time-Interval Analyser

[tggzzz]

I've some boring jobs that I ought to do, but as a displacement activity I'll remind people of a different and neat piece of kit. The truly sad amongst you will note that most of this has already been seen, but is now buried and forgotten in the TEA thread. So sue me.

Inevitably I have far too many boxes that draw graphs of voltage-vs-time (scopes), too many that draw voltage-vs-frequency (spetrum analysers), but until recently nothing that would complete the triumvirate by drawing frequency-vs-time (a modulation domain analyser MDA). I did buy an HP5371 cheaply last year, but it was effin heavy, junk and ended up in the skip – after I rescued an HP10811-60111 OCXO.

So I've been keeping an eye out for an MDA, but mostly they are £600+P&P (on my limit for a toy), often have dents, and even if a display is shown, the self-check screen shows a fault. Not interested. I finally found one at a decent price (even with shipping included) and after remembering to change the voltage settings, I'm a happy camper.



So, what can you do with it? Obviously look at modulated signals up to 200MHz (ch A) or 2.5GHz (ch C), e.g. FM/PSK, or VCO transients as they change frequency. But, since it is fancifully and accurately described as a frequency microscope you can do much more interesting things than that.

The first task was to look at the output of my OCXO as it turned on and warmed up. The display isn't wonderful, but the top thin band shows a "panorama" of the entire f-vs-t graph captured over 800s, and the lower main section is a narrow window of that display.

The first thing to note is the number of digits in the frequency display, and that the vertical frequency scale is +-200Hz. The OCXO starts off 200Hz (20ppm) low, but after 400s it looks pretty close to nominal, but how close?




Or the same information presented as a histogram, vertical scale is logarithmic.



Looking at the histogram of the stable oscillator shows that (relative to the MDA's internal oscillator) it is 621mHz (62ppb low), with an RMS noise of 216mHz. "Frequency microscope" indeed, plus yet another reason for telling people that the M/m difference does matter



But, arguably more interestingly, even with a 200MHz input, it can measure sub-nanosecond risetimes, roughly equivalent to a 1GHz or faster scope. The technique is to measure connect both channels A and B to the same input, channel A with a threshold at 10%, channel B at 90%, and measure the time difference between the two inputs with a resolution of 70ps.

I've previously measured my 74lvc1g14 step generator as having a risetime of ~250ps. The MDA indicates 370ps (and 200ps for 20%-80%). That's close since it is pushing the limits of the instrument; I need to sit down and fully understood the specification graphs in the manual.




And I'm sure it can do more strange and wonderful things

For example, I really must get around to looking at the 1Hz and 1MHz outputs from a cheap GPS receiver, to see if there are glitches and/or cycle slips. Yes, I could just about do that with a logic analyser, but an MDA would be a better tool for that job.

[PA0PBZ]

Interesting: Agilent on the front, HP on the CRT

[maxwell3e10]

Welcome to the club! I first heard about HP53310 on here and now have four of them between home and work 

[PA0PBZ]

Welcome to the club! I first heard about HP53310 on here and now have four of them between home and work 

I have only one    So far 

[tggzzz]

Interesting: Agilent on the front, HP on the CRT

I always used to say,  after the princess Fiorina saga, "the real HP still exists, but it is called Agilent now".

[DeepLink]

Welcome to the club! I first heard about HP53310 on here and now have four of them between home and work 

So you are to blame, that I can’t find a decent priced unit

[Tomorokoshi]

One of these years I'll finish my "Scope Wars: The MDA Strikes Back" project.

[tggzzz]

One of these years I'll finish my "Scope Wars: The MDA Strikes Back" project.

Oooh! That sounds like an excellent troll

Make sure you publicise it so I can have a ringside seat 

[0culus]

Nice writeup! I'm going to have to try that risetime measurement...

I have two of these...the one I use the most is in better shape and has Option 31 (I added the deep memory option myself). Deep memory is easily added (you need 4 of a specific SRAM and to move a couple of jumpers), and it noticeably improves performance when using the panorama mode.

[syau]

Replacing the caps in the power supply is mandatory 

[kj7e]

See here for power supply re-cap BOM (bottom of linked post);
https://www.eevblog.com/forum/repair/hp-53310a-power-supply-troubles/msg2365593/#msg2365593

[tggzzz]

See here for power supply re-cap BOM (bottom of linked post);
https://www.eevblog.com/forum/repair/hp-53310a-power-supply-troubles/msg2365593/#msg2365593

Useful. Thanks for the cross-reference and the BOM.

[0culus]

Can you share the exact settings you are using for risetime measurements? I must have something set up wrong because I get 1 uS for every step-like signal I try, including one that is definitely faster (confirmed by a manual measurement on my 7104).

[tggzzz]

Can you share the exact settings you are using for risetime measurements? I must have something set up wrong because I get 1 uS for every step-like signal I try, including one that is definitely faster (confirmed by a manual measurement on my 7104).

Googling for "hp53310a risetime measurement" leads to https://www.eevblog.com/forum/testgear/hp-53310a-modulation-domain-analyzer-79866/?action=dlattach;attach=706314 I probably got it from there.

The only tricky part was setting the voltages manually. I probably did something like changing the voltage level until it didn't trigger, then calculating the 10% and 90% levels and entering those explicitly.

[0culus]

Can you share the exact settings you are using for risetime measurements? I must have something set up wrong because I get 1 uS for every step-like signal I try, including one that is definitely faster (confirmed by a manual measurement on my 7104).

Googling for "hp53310a risetime measurement" leads to https://www.eevblog.com/forum/testgear/hp-53310a-modulation-domain-analyzer-79866/?action=dlattach;attach=706314 I probably got it from there.

The only tricky part was setting the voltages manually. I probably did something like changing the voltage level until it didn't trigger, then calculating the 10% and 90% levels and entering those explicitly.

Thanks, that document has a lot of useful info. I'll play around with tweaking the settings this weekend.

[artag]

A better link for that document : the copy on eevblog is from google's cache and doesn't have functional links to a number of useful references.

https://web.archive.org/web/20150301064951/http://www.gellerlabs.com/hp53310A.htm