[time-nuts] Lucent KS-24361, HP/Symmetricom Z3809A, Z3810A, Z3811A, Z3812...

GandalfG8 at aol.com GandalfG8 at aol.com
Fri Oct 24 02:19:58 EDT 2014


Ah, hadn't spotted the latches.
 
I've used something similar in the past, might still have a couple around  
somewhere, but my first inclination would be to convert them to standard 
screw  types.
 
That's assuming they would fit of course, but Anthony's photos suggest they 
 should.
 
Regards
 
Nigel
GM8PZR
 
 
In a message dated 24/10/2014 06:26:26 GMT Daylight Time,  
tmiller11147 at verizon.net writes:

I am  surprised the schematics for these have not surfaced yet. Are they 
not 
out  of support now?
I got a set and am awaiting on a power supply and some  connectors. Anyone 
have a source for the latches for the D  connectors?

Tom



----- Original Message ----- 
From:  "Anthony Roby" <aroby at antamy.com>
To: "Discussion of precise time and  frequency measurement" 
<time-nuts at febo.com>
Sent: Thursday,  October 23, 2014 10:39 PM
Subject: Re: [time-nuts] Lucent KS-24361,  HP/Symmetricom Z3809A, Z3810A, 
Z3811A, Z3812...


> My  curiosity got the better of me so I ordered these earlier this week 
and  
> received them today.
>
> I've powered both up and quickly  measured the 10MHz output.  I don't yet 
> have a GPS antenna feed  that I can connect, so couldn't check that out. 
> And I need to look  into why both of the units have the Fault and StdBy 
> lights  illuminated.  I was surprised how compact they are and they 
weight  
> next to nothing.  And they are very nicely made.  I took  the tops off 
both 
> and took some photos (see http://goo.gl/87e8GG),  but have not ventured 
> into unscrewing everything to get to the bottom  of the boards.  From the 
> top, I didn't immediately spot anything  extra on the board for the 10MHz 
> out.  All the extras appear to  be for the GPS, but the underside of the 
> boards may tell a different  story.
>
> Anthony
>
> -----Original  Message-----
> From: time-nuts [mailto:time-nuts-bounces at febo.com] On  Behalf Of Bob 
> Stewart
> Sent: Thursday, October 23, 2014 12:20  PM
> To: Discussion of precise time and frequency measurement
>  Subject: Re: [time-nuts] Lucent KS-24361, HP/Symmetricom Z3809A, Z3810A, 
 
> Z3811A, Z3812...
>
> My units came in today. What I got  appears to be new-in-box. It's 
probably 
> the only thing I'll ever get  with a blue Agilent sticker on the box. =) 
It 
> has a yellow  Symmetricom notice inside the box.
> The circuit board appears to be the  same on both units, but that says 
> nothing about the firmware, of  course. The REF-1 has an Oncore receiver 
> labeled TM-AB - whichever  one that is, small parts to support it, and a 
> TNC connector for the  GPS receiver.
>
> The REF-0 is missing everything related to the  receiver, and has an SMA 
> for the 10MHz output in the space where the  REF-1 has the TNC along with 
a 
> few extra small parts. This is a  shared space with both SMA and TNC 
pads, 
> though they don't seem to  share the same electrical path. Since the SMA 
> and TNC share the same  physical space, even if the 10MHz is available 
> somewhere, you'd have  to do some surgery on the case before you could 
> bring it out.  Probably by adding a hole in the case for the GPS antenna 
> and using  the pad space for the SMA.
>
> It will be a day or two before I  have the bits to apply power and 
connect 
> an antenna. So, that's what  I know. I'd probably just break something if 
I 
> tried to find and  bring out the 10MHz, so I'll have to leave that to 
> someone else. But,  the appropriate signals need to get between the 
boards, 
> so I wonder  what's on the Interface pins? Maybe just arbitration, 1PPS, 
> and  sawtooth comms?
> In my case, I do need the 10MHz, so I'm just as happy  to have bought 
both 
> units at this point. Maybe, down the road,  someone will come up with the 
> mods to convert a REF-1 into a REF-0,  and vice versa, unless the 
firmware 
> prevents that.
>
>  Bob
>     From: GandalfG8--- via time-nuts  <time-nuts at febo.com>
> To: time-nuts at febo.com
> Sent:  Tuesday, October 21, 2014 5:59 AM
> Subject: Re: [time-nuts] Lucent  KS-24361, HP/Symmetricom Z3809A, Z3810A, 
> Z3811A,  Z3812...
>
> It seems from the auction revision table that this  seller has been 
> offering  these for some time, so perhaps  another "hidden" gem:-), but 
> it's perhaps also worth noting that if  this system functions on similar 
> principles to earlier RFTG kit then  the GPS conditioning is only applied 
> to the unit actually containing  the GPS module, with the other unit 
> intended as a standby should the  first one fail.
>
> In other words, unless the system redundancy  is really required most 
users 
> would probably only need the GPS based  unit, or would at least be better 
> off buying two of those for the  same money that the "matched" pair would 
> cost.
>
> The  only advantage, as far as I'm aware anyway, of the non-GPS unit is 
>  that  it contains a 10MHz output.
> However, Skip Withrow published  modification details in January 2013 
> showing how straightforward it  was to add the the 10MHz output, to the 
> RFTGm-II-XO module, the PCB  location for the socket was already 
available, 
> so I would suspect it  wouldn't be too difficult on these either.
>
>  Regards
>
> Nigel
> GM8PZR
>
>
> In a  message dated 20/10/2014 05:53:29 GMT Daylight Time, 
>  stewart.cobb at gmail.com writes:
>
> Fellow  time-nuts,
>
> This (long) post is a review of the HP/Symmetricom  Z3810A (or Z3810AS) 
> GPSDO system built for Lucent circa 2000. I wrote  it because I looked 
for 
> more information before I bought one, and  couldn't find much.
> It's relevant because (as of this writing), you  can buy a full system on 
> the usual auction site for about $150 plus  shipping. For those of you 
> lamenting the dearth of cheap  Thunderbolts, this looks like one of the 
> best deals going. The  description of these objects does not include 
> "GPSDO", so time-nuts  may have missed it. Search for one of the part 
> numbers in the subject  line and you should find it.
>
> So what is it? It's a dual GPSDO  built by HP as a reference (Redundant 
> Frequency and Time Generator,  or RFTG) for a Lucent cell-phone base 
> station, built to Lucent's spec  KS-24361. Internally, it's a close 
cousin 
> of a later-model Z3805A.  Externally, it looks to be almost a drop-in 
> replacement for the  earlier RFTG system built to Lucent's spec KS-24019. 
> That was a  redundant system containing one rubidium (LPRO, in the one I 
> have)  and one OCXO in two almost-identical boxes. That spec went through 
>  several revisions with slightly different nameplates and presumably 
>  slightly different internals. You can generally find one or two examples 
 
> on the auction site (search for RFTG or KS-24019).
>
>  This system is similar, but the two boxes each contain a Milliren
>  (MTI) 260-0624-C 5.000MHz DOCXO, and neither contains a rubidium. The 
>  Milliren DOXCO is the same one used in the later models of the HP Z3805A 
/  
> 58503A. It's a very high-performance DOCXO, in the same class as the  
> legendary HP 10811, and better than the one in most surplus  
Thunderbolts. 
> The 5 MHz output is multiplied up to 10 MHz in at least  one unit, and 15 
> MHz in both units. I don't have the ability to  measure phase noise on 
> these outputs, but I'd be interested to see  the results if someone could.
>
> Nomenclature: The Z3810AS (there  always seems to be an "S" at the
> end) is a system consisting of the  Z3811A (the unit containing a GPS 
> receiver), the Z3812A (the unit  with no GPS receiver), and the Z3809A (a 
> stupid little interconnect  cable). The GPS receiver inside the Z3811A is 
a 
> Motorola device,  presumably some version of an OnCore.
> Where the Z3811A has a TNC GPS  antenna input, the Z3812A has an SMA 
> connector labeled "10MHz TP".  That is indeed a 10 MHz output. It comes 
> active as soon as power is  applied to the unit, and its frequency 
follows 
> the warmup curve of  the OCXO. The two units have identical PCBs (stuffed 
> slightly  differently), and I have no doubt that someone can figure out 
how 
> to  add a 10 MHz output to the Z3811A as well.
>
> Operation: From the  outside, these units are broadly similar to earlier 
> units in the  Lucent RFTG series. The (extremely valuable) website run by 
> Didier,  KO4BB, has a lot of information on those earlier units, much of 
> which  still applies here. The purpose of these units was to provide a 
>  reliable source of frequency and timing information to the cell-site 
>  electronics. The 15 MHz outputs from both units were connected to a 
power  
> combiner/splitter and directed to various parts of the transmitter.  The 
> units negotiate with each other so that only one 15 MHz output is  active 
> at a time. The outputs labeled "RS422/1PPS" contained a 4800  baud (?) 
> serial time code as well as the PPS signal, which were sent  to the 
control 
> computer.
>
> Power is applied to the  connector labeled "+24VDC" and "P1", in exactly 
> the same way as the  earlier RFTG units. Apply +24V to pin 1 and the 
other 
> side of the  power supply (GND or RTN) to pin 2. In these units, that 
power 
> supply  goes directly to an isolated Lucent DC/DC converter brick labeled 
>  "IN: DC 18-36, 1.9A". Presumably you can run both units with a 4-amp 
>  supply.
>
> Once you have applied power, connect the Z3809A cable  between the jacks 
> labeled "INTERFACE J5" on each unit. The earlier  RFTG units used a 
special 
> cable between two DE-9 connectors, and it  mattered which end of the 
cable 
> connected to which unit. The  interconnect for these units is a 
> high-density DE-15 connector (like  a VGA plug). The Z3809A cable is so 
> short that the two units need to  be stacked one above the other, or the 
> cable won't reach. It doesn't  seem to matter which end of the cable goes 
> to which unit. I don't  know whether it's a straight-through cable, or 
> whether you could use  a VGA cable as a substitute.
>
> When you apply power, all the  LEDs on the front panel will flash. The 
"NO 
> GPS" light will continue  flashing until you connect a GPS antenna.
> Once it sees a satellite,  the light will stop flashing and remain on.
> The unit will conduct a  self-survey for several hours. Eventually, if 
all 
> is well, the Z3812A  ("REF 0" on its front panel) will show one green 
"ON" 
> light and the  Z3811A ("REF 1") will show one yellow "STBY"
> light. This means that  the Z3812A is actually transmitting its 15MHz 
> output, and the other  one is silently waiting to take over if it fails.
>
> Most  time-nuts want to see more than a pretty green light. The old RFTG 
>  series allowed you to hook up a PC to the "RS422/PPS" port and peek 
under  
> the hood with a diagnostic program. The program is available on the  
KO4BB 
> website. It is written for an old version of Windows, and I had  no luck 
> getting it to run under Windows 7. It does run under WINE  (the Windows 
> emulator for Linux) on Ubuntu 12.04 LTS.
> To use  it, you need to make an adapter cable to connect the oddball
> RS-422  pinout to a conventional PC RS-232 pinout. The adapter cable 
looks 
>  like this:
>
> RFTG PC
>
> DE-9P DE-9S
>
>  7 <----------> 5
>
> 8 <----------> 3
>
>  9 <----------> 2
>
> (According to the official specs, this  is cheating, because you're 
> connecting the negative side of the  differential RS-422 signals to the 
> RS-232, and ignoring the positive  side of the differential signals.
> However, it's a standard hack, and  it's worked every time I've tried
> it.)
>
> With that  adapter, you can see the periodic timetag reports from the 
unit. 
> The  RFTG program will interpret these timetags when it starts up in 
>  "normal mode". However, when I try to use any of the diagnostic features 
 
> built into the program, it crashes WINE. The timetag output was  required 
> for compatibility, but I suspect that HP didn't bother to  implement the 
> Lucent diagnostics.
>
> Instead, they added  a connector which is not on the previous RFTG 
series. 
> That connector  is labeled, logically enough, "J8-DIAGNOSTIC".
> It too is wired with  RS-422, so you need to use the same adapter cable 
as 
> before. Once you  do, you'll find that this connector speaks the usual HP 
> SCPI command  set (Hooray!). I used the official SATSTAT program (again 
> under WINE  on 12.04 LTS), but I'm sure that other programs written for 
> this  command set will work as well. The default SATSTAT serial port 
>  settings of 9600-8-N-1 worked for me.
>
> After about 24 hours,  with a poorly-sited indoor GPS antenna, my system 
> has converged to  TFOM=3, FFOM=0 (the best possible numbers), and a 
> "predicted 24-hour  holdover uncertainty" of 5.2 microseconds, which is 
not 
> too shabby.  It found the correct day and year without any assistance, so 
> if it  has a "GPS week number rollover" problem, it's still in the 
future. 
> I  don't currently have the ability to compare the 10 MHz output to 
>  anything else. Again, if someone else can, I'd be interested to see the  
> results.
>
> Additional Notes: The parts on the boards  all have date codes of 1998 or 
> 1999. The Motorola GPS receiver has a  firmware label that reads 
> "02/04/00". The SCPI error logs inside the  HP units were virgin when I 
> first got them. They had 84 and 94 power  cycles, respectively.
> Before the GPS receiver acquired time, the error  log timestamps read
> "2000-05-09 00:00:00", which I interpret as a  firmware release date.
>
> The PCB has an interesting feature.  Next to each soldered-in pin of the 
> Milliren OCXO is a single-pin  socket soldered into the board. I'm 
guessing 
> this was used in  manufacturing, to temporarily install a Milliren and 
> confirm that the  system worked before permanently soldering it in. (At 
> production  prices, the Milliren would have cost far more than the rest 
of 
> the  PCB.) You might be able to use this in reverse, if you have a set of 
>  Millirens to test from another source.
>
> The Z3809A interconnect  cable has three of the 15 pins on each end 
clipped 
> a bit shorter than  the rest. Not so short that they won't eventually 
make 
> contact, but  short enough to make contact later than the rest. Don't 
know 
> why, but  it's clearly deliberate. A lot of hot-plug connectors are built 
> that  way, including USB connectors. I have no idea what the pinout of 
the 
>  interconnect is.
>
> The redundant system slaves both DOCXOs to  the same GPS reference.
> Inside the GPS loop bandwidth, the two  oscillators will have almost the 
> same frequency and will differ only  by phase noise and short-term 
> stability. This is almost a perfect  setup for experimenting with certain 
> kinds of time-nut measurements,  assuming someone can figure out how to 
get 
> 10MHz out of the Z3811A  unit. If you then command both units into 
> holdover, you could measure  longer-term stability as well.
>
> The units are described as "new  in factory sealed box". After an 
> archeological investigation of the  various strata of labels and tape on 
> the boxes, I would say that's  probably accurate. My set seems to have 
been 
> shipped from the Agilent  factory in Korea to Symmetricom in Sunnyvale, 
CA 
> sometime in August,  2000, shortly after it was built, and remained 
> untouched until I  opened it. I'm guessing it was built and saved as part 
> of a spares  program for Lucent, and kept until Lucent decided they 
didn't 
> need  spares any more.
>
> I have no connection with the current seller  of these units (or any 
other 
> sellers, for that matter) except as a  satisfied customer. I think I'll 
> order another set as a spare, before  the feeding frenzy hits.
>
> Request for help: Both the SatStat  and RFTG programs run under WINE on 
> stock Ubuntu 12.04 LTS (32-bit)  without any tricks or special 
> configuration. Neither seems to run  under WINE on Ubuntu 14.04 LTS 
> (64-bit). I am a WINE novice. Any  hints from WINE experts would be 
> appreciated. Also, I've been able to  run TimeLab under WINE, but I can't 
> connect it to my USB-to-488  interface, so I can't take data. If anyone 
can 
> tell me how to set  that up, I'd be extremely grateful.
>
> Cheers!
>  --Stu
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