Hi, This is my first posting to the group having been in "lurk mode" for a month or so.
I have been able to "liberate" a quantity of (working) frequency references used in CDMA base stations for a small group of enthusiasts in Australia & New Zealand (the ANZAC T & F Nuts). It responds to the SCPI command of *IDN? as a "HEWLETT-PACKARD,Z3815A . These modules incorporate either HP's ubiquitous "Hockey-Puck" E1938A oscillator (designed in part by Rick Karlquist) or an equivalent C-MAC double-ovened oscillator. The motherboard performs all the necessary 1pps housekeeping from the internal Furuno or Motorola GPS engine and produces a disciplined 10 MHz output together with other phase locked frequencies (19.6608 MHz, E1, T1 references etc). One variant of the units respond to (nearly ?) all SPCI commands from SatStat, so there's a lot of available performance data at hand. Performance is stunning to say the least - enhanced no doubt by the E1938A and some very smart on-board "timekeeping". Murray, from across the Tasman (ZL1BPU in New Zealand), has graciously agreed (persuaded ?) to attempt some qualification testing on the units and I hope to report back the details when they come to hand. (Murray's VNG Clock in a Box design at http://www.qsl.net/zl1bpu/MICRO/index.htm is a cheaper and simpler approach, but given a double-ovened oscillator, makes an interesting comparison with the Z3815A !) I can possibly provide 1pps stability and EFC voltage plots if anyone in the group is interested. (Programmes courtesy of Murray, ZL1BPU and Con, ZL2AFP) Cheers, Kit Scally VK2LL Sydney Australia _______________________________________________ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts