HP 58503A GPSDO - Option H14 (1PP2S) Removal? - Page 1
Forum section: electronics / testgear

author: pamphonica
author_rank: Regular Contributor
timestamp: February 19, 2020, 08:10:26 pm
content: 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

author: TheSteve
author_rank: Unknown
timestamp: February 19, 2020, 08:34:31 pm
content: If you can get it, I'd try firmware that doesn't have the option.

author: pamphonica
author_rank: Regular Contributor
timestamp: February 20, 2020, 03:58:39 pm
content: 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

author: TheSteve
author_rank: Unknown
timestamp: February 20, 2020, 05:15:18 pm
content: 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?

author: pamphonica
author_rank: Regular Contributor
timestamp: February 20, 2020, 05:23:53 pm
content: 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.

author: Theboel
author_rank: Frequent Contributor
timestamp: April 03, 2020, 06:39:10 am
content: 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.htmhttps://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

author: pamphonica
author_rank: Regular Contributor
timestamp: April 03, 2020, 04:36:42 pm
content: All sorted out by installing new flash ROMs, with the Rev-A firmware from Github.https://github.com/willhb/HP-58503A-FirmwareThis 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.-JeremyPS. 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.

author: pamphonica
author_rank: Regular Contributor
timestamp: April 03, 2020, 04:53:38 pm
content: 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

author: Theboel
author_rank: Frequent Contributor
timestamp: April 03, 2020, 05:27:49 pm
content: 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

author: pamphonica
author_rank: Regular Contributor
timestamp: April 05, 2020, 01:20:35 pm
content: 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

author: pamphonica
author_rank: Regular Contributor
timestamp: April 05, 2020, 01:30:34 pm
content: Photo of new Meanwell PT-65C power supply installed. The RPT-60C definitely ran too hot despite having near-identical specifications.-Jeremy

author: Theboel
author_rank: Frequent Contributor
timestamp: April 05, 2020, 02:43:39 pm
content: 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