Did Trimble not make it through the last 1024 week roll-over ...
I see lots of Trimble units for sale cheap. I have thought of getting one of these "Cheap", GPS units(L1/L2 ... +)
I have retired from Surveying, but now I'm playing with drones for photogrammetry ... so far just having fun, but I want to set targets(with GPS Data), and I no longer have any GPS, other than a dozen Magellan ProMark 10cm, L1 GPS setups.
I am not going to get involved with any property lines, corners, or anything of the sort... probably just making Orthophotos(with no lines or declarations of accuracy/precision, unless they are declarations of basic un-usefulness ... If I think I have the stamina of walking around over hills and dales and the will to get back to work, I will work with surveyors and let them do all the GPS carap and let them do the declarations/certifications.
I think, I just need something to do, that would be fun at the same time.
ANYWAY, about Trimble ... are all these cheap Trimble GPS units, basically "Bricked"?
Not sure about the Trimble units. I've got Leica GPS 300's, still working, serviced by Chris in Poland, they have the GPS rollover issue, I had to write software to clean up the files anyway, so I correct the date in the RINEX files, these are only used for static GPS, but they're surprisingly good, as they have both P1 and P2 and produce clean data, according to AUSPOS. They've got an oven crystal oscillator, which seems to provide a stable clock (heated to a constant temperature), the latest models have temperature compensated oscillators.
There's a guy in the US that sells second hand units, the first thing I'd do would be to send them directly to Poland for a service, Chris installs new bios batteries and installs the last firmware.
I have used the Trimble 4000sse or ssi and corrected the date either by text editor (watch the spacing!) or by telling TEQC with the correct -week #### option. I believe Jim Frame also has a fleet of these that he occasionally uses.
Yes, I have a bunch of 4000SSi and a couple of 4000SSe units that I sometimes put into service. These devices are old enough now that I've had some experience failures that are beyond my ability to diagnose, let alone repair. But for most of them, the only problems are internal batteries that die and the rollover date issue that Bill mentioned. The former can be taken care of by anyone handy with a soldering iron and a few bucks for new primary lithium cells, while the latter is elegantly addressed with a firmware update that Keelan Lightfoot developed and makes available on his Beefchicken Industries site. Other than that, as long as you have cables and batteries and antennas, they offer a robust L1/L2 solution.
Firmware upload requires a computer with a true serial interface and the loader software, which is available online (I think UNAVCO still hosts it, but I haven't checked lately). I don't recall if I've accomplished the upload from a Windows 10 command window, or if I used an old laptop that I keep around for legacy purposes.
I've seen 4000SSi units on eBay recently for as little as $50 apiece, though most are priced in the $100 to $250 range. Shipping can be costly, as they're relatively large, especially if you get the hard case with it.
As guide, the Trimble "Week Number Roll Over (WNRO)" firmware issue on the 20th August 2023 knocked out everything up to and including my 5700 but not my R7 GNSS or NetR5 which were later than the critical impacted firmware version 4.30.
Trimble have made an option code freely available to allow updating compliant devices to their minimum required firmware level even if out of warranty.
Anything earlier (5700 & 5800 V1 or older) needs one of the workarounds, but it can be messy.
Up until about a year ago when my receiver crapped out I was pretty regularly using the Zephyr Geodetic with a 5700 receiver, 5800 rover, TSC2 with Survey Controller 12.50 and a Trimark III radio with few problems. Couldn't get near trees (even leafless) over 10' high or shacks but it was doing what I needed with it. Several years ago I did have to flash the receiver with their 2.32 firmware to get through. I just got a deal on a couple R8-3's though so I may not put anything more into the old system. Want a deal on an old setup? I replaced the 5700 with one that's pristine but has no RTK option installed (and I couldn't find a hack to get it in there). It still does static just fine, though.