I recently picked up a couple non-functional Ashtech Z-12 receivers with the external frequency input (these appear to PLL an internal TCXO; I understand there are other models where they replace the TCXO completely).
I was hoping to use them both better data sources for common view time transfer with better performance than the GPS L1/CA that I've been using; as well as using them for ground truth data for a SDR semi-codeless CRPA receiver I'm slowly building. These units were hanging at startup at "Downloading channel". I determined that they would work a single time if the memory were cleared (by holding an arrow, right for external up for internal, during start). Because the internal 3.6v primary cell batteries were reading about 40mv I took a guess that the low battery was causing memory corruption across restarts. New batteries and a bit of soldering later, and they are working reliably across restarts, locking sats on L1/L2, talking on RS232, etc. (hurrah). Hopefully this message in the archives is useful if someone else encounters similar symptoms. Before I go further I was wondering if anyone knew of a source for firmware for these old units? One of mine is marked "Z-12 700751-6 (b)", unfortunately it seems ashtech has been sold many times, and the old web/ftp sites have been scattered to the wind. The nearest I was able to find was this page http://kb.unavco.org/kb/article/astech-micro-z---firmware,-firmware-release-notes,-firmware-upload-programs-and-how-to-use-them-368.html with micro-Z firmware. [If there is a relevant GNSS nuts list, I'd be glad to hear about it-- my interest is in CVTT but perhaps somewhere else there is a den of people obsessed with old survey hardware that would prefer these questions.] _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.