Hi, I've been meaning to unload this 4000 unit but I had forgotten to post it on here !
It's a Trimble 4000 SSi Geodetic Surveyor (model 24840-01), in good working condition.
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** Summary of specs :
- 9-channel L1 + L2 (carrier + phase)
- 1MB of onboard storage for logs, static surveys etc
- static survey accuracy : horizontal 5mm + baseline * 1E-6; vertical 10mm + baseline * 1E-6
- kinematic survey (RTK) : 20mm + baseline * 1E-6
- 2 serial ports
- RTCM-104 in/output
- NMEA-0183 out
- 1PPS out
- Eventmarker input
- QA/QC stats
- *RTK (see note below)
The 4000 series firmware originally could not deal with the most recent GPS "week number rollover" that occured in 2019. However, I have installed (and tested) the unofficial firmware patch that fixes this problem and allows the unit to set the date properly.
I bought this unit for inexpensive, post-processed static surveys and for this task it's perfectly usable. Having an actual keypad, screen and builtin memory makes it very convenient to setup (no computer or datacollector required !).
Note : the firmware and log memory are stored on battery-backed internal memory. I have just installed fresh batteries on the main board (firmware), and the batteries on the extra storage cards are still in excellent shape (~ 3.7V, see photos) and should last a good many years.
RTK : it doesn't support the latest RTCM3.x standards so compatibility may be an issue depending on gear; I have no idea.
** Included :
- battery "caddy" (that black plastic module attached to the bottom. The DB9M connector your see will not work since this GPS did not have the "4 serial ports" option. The barrel jack is a 5.5mm/2.5mm connector for external power (saves one expensive LEMO cable ...)
- hard plastic carrying case
- LEMO to N-male antenna cable. Those are expensive !
- LEMO to DB9 data cable. These too !
- (will be sent via internet) : all documentation, software and firmware I could find on the net. It was all freely available, but scattered in many places and it took hours to track everything down.
Batteries not included but it runs on anything DC 11-35V. I was using a cordless drill battery pack lately...
No antenna included; I still need it and it should be easy enough to find a 22020 on ebay for cheap.
Make an offer...
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I offer you good luck!!!
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We had three of these and?ÿ pile of ASHTECH?ÿ stuff in the warehouse.
I was glad I wasn't involved in the attempt to sell it, and would have gladly donated it to anyone interested because our cost to legally dispose of exceeded the budget to do it as I was told.
Neat history and cool that they still function, mostly.
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The 4000sse and ssi are still useful static GPS-only machines where you have reasonable sky visibility. Some people on here still use them. Not having to deal with the week number on this one is a bonus.
They will still work for a bit longer. When L2C and L5 are fully implemented, neither these receivers nor other legacy receivers from any manufacturer will work. The date is a little in flux, at one time I think it was 2023, but might be pushed out a bit now, but will be this decade sometime. IIRC, 2027-29 time frame.
SHG
neither these receivers nor other legacy receivers from any manufacturer will work
What do you mean by that, are you saying they would deactivate L1 and L2 transmission on all SVs ? That sounds like breaking an awful lot of stuff for no obvious gain, and can find no statement to that effect. And I don't see how L2C would prevent a legacy receiver from measuring phase on L2 ? As for L5, it's on a different frequency anyway, so it shouldn't matter... Legacy L1 should continue to work for a long time (according to wikipedia L1C is designed to be backwards-compatible with the standard C/A code). But if I misunderstood or you have further information I'm happy to be corrected.
Discontinuation of Codeless and Semi-Codeless GPS Access
The USG commits to maintaining the existing GPS L1 C/A, L1 P(Y), L2C,
and L2 P(Y) signal characteristics that enable codeless and semi-codeless
GPS access until at least two years after there are 24 operational satellites
broadcasting L5 with fully functional navigation messages. Barring a
national security requirement, the USG does not intend to change these
signal characteristics before then. The availability of 24 satellites
broadcasting the L5 signal is estimated to occur in 2027. Maintaining the
legacy signal characteristics for the stated period of time will allow for the
orderly and systematic transition of users of semi-codeless and codeless
receiving equipment to the use of equipment using modernized civil-coded
signals. Note that it is expected that 24 operational satellites broadcasting
L2C will be available by 2020, with the corresponding ground segment
control capability available by 2023, enabling transition to L2C by 2023.
Civilian users of GPS are encouraged to start their planning for transition
now.?ÿ
So, around 2029 ALL survey receivers without L2C and L5 will probably be paper weights. I suppose the DoD could extend the deadline, but this transition has been proposed for more than a decade, not new news. Yes there will be a boatload of legacy survey receivers affected, but all of those will be approaching 20+ years old by 2029.
Note that this does NOT affect typical vehicle navigation systems, etc., ONLY high accuracy receivers.
SHG
our cost to legally dispose of exceeded the budget to do it as I was told.
4000SSi receivers have reached the point where the cost of shipping exceeds the market value.
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It depends on the provenance.?ÿ Most of the ones on ebay are "untested" with no accessories, cables, or battery charger/office supply.?ÿ Those, yeah. If they come with a description that says the still work, they tend to still command?ÿ a little more.
Discontinuation of Codeless and Semi-Codeless GPS Access
Thanks for the link. I was on that website earlier poking around and must've missed that page !
At any rate, 2029 is still 7 years down the road. Until then, I think this unit has got to be among the least expensive options for basic L1+L2 static. AFAIK you can't otherwise buy any dual-frequency receiver for less than a few hundred $...
For a pro surveyor, I agree there is no reason to invest any time or effort in this generation of receivers, but for the weekender / hobbyist, I would argue these are still worth more than the 30-40$ shipping cost... Heck just a single LEMO connector sells for about that !
I would argue these are still worth more than the 30-40$ shipping cost.
I was talking about a bare receiver with unknown (or known bad) internal battery condition.?ÿ Add in a hard case, L1/L2 antenna, battery cable, serial cable, antenna cable, known good internal bats and maybe you're at two or three hundred -- if you can find a buyer.
I know that the last couple I bought (dead internal bats but with case and cables) I only paid $100 or so plus shipping.
