[time-nuts] Lucent KS-24361, HP/Symmetricom Z3809A, Z3810A, Z3811A, Z3812A GPSDO system

Dave M dgminala at mediacombb.net
Mon Oct 20 14:31:21 EDT 2014

Arghhhh!  I read the whole article on the mod but just didn't see the ruler. 

Thanks for the alert,
Dave M

Anthony Roby wrote:
> In the link below there's a photo of one of the units with a ruler
> against it - 11" wide.
> Anthony
> -----Original Message-----
> From: time-nuts [mailto:time-nuts-bounces at febo.com] On Behalf Of Dave
> M
> Sent: Monday, October 20, 2014 10:22 AM
> To: Discussion of precise time and frequency measurement
> Subject: Re: [time-nuts] Lucent KS-24361, HP/Symmetricom Z3809A,
> Z3810A, Z3811A, Z3812A GPSDO system
> Stu,
> Many thanks for the heads-up on htese units.  Great deals.
> Can you advise the size of these units?  Are they full-size 19" rack
> mount or the half-size units like the Z3801A?
> Can the REF-1 unit (the one with the GPS receiver) be operated
> separately from the REF-0 unit?
> There is a mod on Didier's site to add the 10 MHz output to the RFTGm
> unit at
> http://www.ko4bb.com/manuals/download.php?file=05)_GPS_Timing/Lucent_RFTGm_RFTGm-II-XO_GPSDO_modification_to_add_10MHz.pdf.
> I don't know if the mod will apply to the units on Ebay right now,
> but it's quite possible that it does.
> Cheers,
> Dave M
> Stewart Cobb wrote:
>> 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).

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