HP 58503A GPSDO - Option H14 (1PP2S) Removal?

[pamphonica]

This recently-acquired GPSDO is working very nicely after a PSU replacement and a good clean inside and out. These things run 24/7 so the grubby state was not surprising.
But it has Option "H14" for CDMA use so only gives 1PP2S (even seconds only) not 1PPS so I can't use it for disciplining another oscillator like my Rubidium.

No-one I can find has successfully "removed" this option.  Does anyone have any clues?

I've probed inside and cannot find any 1PPS points.

Could they really have put in different firmware? If so. I will need to blow some new ROMs. The current ones are marked:
58503-800007 U11/2L, U12/1L, U13/2M, U14/1M.

Apparently the DIP switches don't affect it either. And I have tried sending a 1PPS command from Lady Heather but that did not work.

Any ideas anyone?

thanks
-Jeremy

[TheSteve]

If you can get it, I'd try firmware that doesn't have the option.

[pamphonica]

I think you are right - they have probably put in alternative firmware for Option H-14. *IDN? gives a firmware load of 3504A00166.USA_H14.1A. So it looks like a special version.

I've found the firmware binaries for another version online (https://github.com/willhb/HP-58503A-Firmware).
And I've ordered some 29F010-120JI flash chips.  So I'll give new firmware a try while not destroying the old!
Even though mine is marked Rev C and the binaries refer to Rev A.
My only issue is that my HP85803A has the "Option 1" front panel display as well.  This may also need different firmware - we'll see.
HP did issue firmware updates but they have vanished, so I can't just do a serial port firmware update using SatStat (but thank you Didier - http://www.ko4bb.com/getsimple/index.php?id=manuals&dir=02_GPS_Timing/SatStat).

Does anyone have the original HP firmware upgrade file, rather than the flash binaries?

Or does anyone have binaries that are definitely for a version with the front panel display (Option 1)?

-Jeremy

[TheSteve]

I have a 58503B but my firmware is in a single flash chip that isn't socketed. I don't think the firmware is any different for option 1. Are your chips socketed?

[pamphonica]

Yes, 4x socketed PLC-32 chips. AM29F010-120s according to the Github binaries listing.
You can just see the edges of them poking out between the edge of the psu cradle and the two cream IDC connectors.

[Theboel]

Hi,

Have You succeed find the right firmware ?

I have 5pcs 58503A but The do not have option 1 (front display) if anything I can do please let me know.

But If I may my suggestion is :
1. Try to use Tom Van Baak Divider so You can divide 10MHz to 1HZ with only 1 PIC its small enough so no body know You "cheat it"
http://leapsecond.com/pic/picdiv.htm
https://tapr.org/product/tadd-2-mini-pulse-per-second-divider/

2. Changed Your PLL/FLL to accept your 58503A output.

Why I suggest it because lack of documentation can really made a headache to You.   

Anton

[pamphonica]

All sorted out by installing new flash ROMs, with the Rev-A firmware from Github. https://github.com/willhb/HP-58503A-Firmware
This earlier firmware version supports the Option 001 front panel display and buttons fine. And I now have 1PPS!
I have taken dumps of the RevC (H14) firmware just in case, but it's not really of much use as it has the CDMA-style 1PP2S output.
-Jeremy

PS. The "New in original packaging" flash ROMs from china turned out to be an assortment of used devices from a range of years, full of data.
But they all erased and re-flashed just fine, thanks to my aged All-07A programmer and DOS software on a Win98SE computer.

[pamphonica]

By the way, Anton, do any of your 58503A machines have RevB or RevC firmware?
Now I know the standard RevA firmware works, I would welcome a further update if anyone can dump the binaries for me.
-Jeremy

[Theboel]

Hi Pamphonica,

So it must be You who posted in HP mailing list about 58503A.
I believe all my 58503A have rev E.

btw I am interested with Your PSU choice are You sure its strong enough ?
and if I may pay attention to IC regulator with HS near the front panel its Hot in mine I replaced it with a bigger one.

Anton

[pamphonica]

Yes, that was me on the HP list as well - getting desperate!

The PSU is actually fine now. I initially tried a smaller Meanwell RPT-60C (photo above) but that did get far too hot.  I replaced that with a PT-65C and it runs cool.  Nothing on it gets more than warm, which is perfect.
I did not find I needed larger heatsinks.  But it's a tight fit vertically, so mount it so the top is clear of the lid.

If you can do dumps of the RevE firmware I would be very interested :-)
Or do you know a way to re-flash the firmware? via GPIB?

Jeremy

[pamphonica]

Photo of new Meanwell PT-65C power supply installed.  The RPT-60C definitely ran too hot despite having near-identical specifications.
-Jeremy

[Theboel]

Hi Jeremy,

Please look at the Heat sink I circle in red if its Hot consider to replace it to a bigger one.
About ROM let me find procedure and tools to dump it.

Anton