Hello everyone, I am new to the list and currently looking for a timing standard for a VLBI application. After some searching I have decided to use two thunderbolts for a first attempt and now have some questions regarding the different available versions.
There seem to be two types of Thunderbolts available on eBay right now. One is the "flat" board mount version without PSU and which requires a (+12V, -12V, +5V) power supply. The other is the "boxed" version with integrated PSU and which requires 24V. These are all old Thunderbolts with 8 channel GPS. The new Thunderbolt E with 12 channels obviously doesn't show up on eBay yet. (See [1] for comparison) My first question concerns the power supply. [2] shows that the output phase noise is significantly dependent on the PSU. How does the integrated PSU of the boxed version compare to the PSUs tested in [2]? Is it worth getting the boxed (somewhat more expensive on eBay) version just for the PSU? My second question is about the Thunderbolt's OCXO. [3] shows how to replace the built in OCXO with a more stable one and suggest that not all Thunderbolts have the same OCXOs. The bad OCXO in [3] appears to be from PIEZO and has S/N 1384. The better Thunderbolts apparently have "10811-class" OCXOs (like the replacement). Neither, unfortunately, match the labeling of the OCXOs seen on eBay (e.g. [4]). Is there an easy way to distinguish these different Thunderbolts? Thanks, Markus [1] http://www.febo.com/pipermail/time-nuts/2008-May/031370.html [2] http://www.leapsecond.com/pages/tbolt/noise.htm [3] http://www.thegleam.com/ke5fx/tbolt.htm [4] http://cgi.ebay.de/ws/eBayISAPI.dll?ViewItem&ssPageName=STRK:MEWAX:IT&item=170300146215 _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
