HP 53310A Modulation Domain Analyzer -frequency microscope-

[maxwell3e10]

Here is the summary of the HP53310 frequency standard deviation for counting its own internal reference as a function of the time sampling interval (called "Interval at center"). As shown in this post it is actually equal to 1/3 of the normal gate time for a counter: https://www.eevblog.com/forum/metrology/hp53310a-and-other-counter-allan-deviation/msg2342007/#msg2342007
EDIT: The plot is updated. After comparing two HP53310 and fixing the power supply in one, the results are better

[kj7e]

Short video showing how the MDA can be used to tune a reference oscillator more quickly than with a counter.

https://youtu.be/ly6b49ZyaRg

[kj7e]

Here's how to install option 001 (extended memory) in a 53310A that came without it (if anybody's interested to upgrade his MDA):

You need 4 Cypress CY7C194-25PC (or Hitachi HM6708P-25 or Motorola MCM6208P25 or equivalent) 64k*4 SRAM chips (DIL24 casing) and one 2.54mm jumper.

Disconnect the connectors from the CRT display board and lift the board in its guide a few centimeters so the sockets lalbeled U68~U71 become accessible. Insert the SRAM chips in the sockets. Move the two jumpers XW2 and XW7 from the position "16k" to "64k". Place a jumper on XW8/SEL1. All these jumpers are located in close proximity of the SRAM sockets and can be easily accessed with the CRT board lifted.

After this, slide the CRT board back down and reconnect all the connectors. That's it, now your MDA should report the extended memory option installed.

Have fun,
Thomas

Worked perfect, thanks Tom!









Edit:  I have 4 extra NOS Cypress SRAM chips if anyone else is would like to add the extended memory.

[bitseeker]

Edit:  I have 4 extra NOS Cypress SRAM chips if anyone else is would like to add the extended memory.

Yep. I just don't have a 53310A for them to go into, yet. But it's on the shopping list.

[kj7e]

For power supply repair and parts info, I posted some photos and attached an xls spreadsheet with Digikey part numbers here;
https://www.eevblog.com/forum/repair/hp-53310a-power-supply-troubles/msg2365593/#msg2365593

[mark03]

If anyone needs to replace a defective part in their 53310a, send me a PM.  I acquired four of these MDAs at auction a couple of years ago, sold one and kept two.  Out of the four units, one had been cannibalized for its display PCB but was otherwise OK.  I searched for a replacement without success, and at this point prices for complete units are so low that it's not worth fixing/shipping a full analyzer anyway.  So, time to part it out.  Forum members with a good story may get a special price

Edit... This was a rather strange unit, originally built with option 031 but later with that option deleted, yet some (all?) of the hardware left inside.  Boards / part numbers available:

53310-60007  A1 (main board with extended memory)
53310-69002  A2 (input) somewhat inexplicably with four BNC connectors but not the part number of an option 030 or 031 A2 board
53310-60017  A3 (CPU)
53310-60014  A12 (LO)

CRT, front panel, back panel may try to sell as a single "carcass".

[mark03]

Has anyone needed to replace the battery-backed "Zeropower SRAM" on the CPU board yet?  part # M48Z18-100PC.  ST's datasheet says they are good for at least ten years of power-off time.  Mine has a date code from 1997!

[mightyohm]

Has anyone needed to replace the battery-backed "Zeropower SRAM" on the CPU board yet?  part # M48Z18-100PC.  ST's datasheet says they are good for at least ten years of power-off time.  Mine has a date code from 1997!

Today I replaced the ST M48Z18B Zeropower NVRAM in with new Dallas DS1225AD-150+.
One of my MDAs uses a M48Z18B-15, which is why I had ordered the slower Dallas device. If I had known the other MDA had a -10 I would have ordered a faster replacement for both. I suspect that it's not very critical.
I was able to read the existing contents of the NVRAM with my GQ USB programmer and program the new ICs before installing them.
Everything seems to be working. Saved states were preserved.
The NVRAM is socketed which makes the job very easy. (thanks HP!)
Now I should be good for another 10-20 years..

[artag]

Is it important to preserve the NVRAM contents or will the self-calibration replace everything ?

[mightyohm]

Is it important to preserve the NVRAM contents or will the self-calibration replace everything ?

I don't know, so I decided to play it safe and copy the contents.

The contents are mostly not human readable, but the CPU board firmware version is stored as a string in NVRAM...  Not sure what happens if that string is missing or if it does not match the currently installed firmware.

[maxwell3e10]

The service manual simply says: Key-down powerup may be performed on the HP 53310A before selftests are invoked. If the data stored in non-volatile memory is corrupt as indicated by improper operation, perform the "Key-down Powerup" and the "Calibration" procedures in Chapter 3 (Adjustments and Calibration).

So it's probably OK if NVRAM is lost, since the calibration procedure is really easy.

[zrq]

Does anyone have a BOM for recapping the 53310A? My unit is a late Malaysia Agilent version, but still kind of afraid...
Also I would be interested if any one in Europe would like to sell some parts for retrofitting Opt. 31 or 30? (although not very likely...)

[maxwell3e10]

There is a thread on replacing capacitors in the power supply which gives the list of electrolytic capacitors
https://www.eevblog.com/forum/repair/hp-53310a-power-supply-troubles/?all
They do tend to leak in some units.