My understanding is that you have the older red box. Manual for the red box is there:
http://www.ko4bb.com/Manuals/05%29_GPS_Timing/Trimble/Trimble_-_Thunderbolt/ ThunderBolt_Datasheet_%28red_box%29.pdf The power spec is 24V nominal, 18V min to 36V max Mine has been running off a small open frame linear 24V supply for several years. If it does not work at 28V, there must be something wrong with it. I do not recommend trying a voltage higher than 36V unless you have a couple Franklins to spare. My opinion is that it would be best to try and troubleshoot the problem first. A power supply problem should not be too hard to identify, knowing that internally, the Thunderbolt runs from +5V and +/- 12V. I do not have the detailed specs on these voltages, but the +12V drives the oven, so it should be stable, even though the nominal value is probably not too critical. The -12V only drives the RS-232, so it is probably not critical at all. The 5V drives a lot of logic and should probably be within 0.25V or better. I suspect the 5V drives the DAC that drives the EFC, but there must be another regulator/reference between the 5V and the DAC reference input. I believe TVB did some voltage sensitivity test at one point on the Group-buy TBs, but off-hand, I do not remember. Didier -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Mark Sims Sent: Thursday, June 10, 2010 5:33 PM To: [email protected] Subject: [time-nuts] Thunderbolt not seeing satellites I'm not sure of the required power spec, but 28V may be too low. These were meant to run off a telco power bus (nominal 48V). I run mine at 40V (from a Tek PS503A mounted in a TM501 mainframe, unit connected across the + and - supply terminals, outputs set to +/- 20V). It won't run at 28V. ---------------- Input voltage to the poor performing unit is about 28VDC. _________________________________________________________________ The New Busy is not the old busy. Search, chat and e-mail from your inbox. http://www.windowslive.com/campaign/thenewbusy?ocid=PID28326::T:WLMTAGL:ON:W L:en-US:WM_HMP:042010_3 _______________________________________________ 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. _______________________________________________ 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.
