Thanks for the reply. I found that the 12v current is only 60ma. I suppose that means the Osc. heater is not working. I'm not having much luck with this time nuts stuff. First the FRK and now the thunderbolt. Guess I'll start looking for another one.
Garren On Feb 9, 2013, at 6:01 AM, "Bob Camp" <li...@rtty.us> wrote: > Hi > > DAC clamped at -5 volts suggests that the TBolt has issues. First thing to > check is the -12 volt supply. If it's missing, the DAC will indicate -5 on > the screen and be sitting at 0 in real life. There are a couple other things > in the DAC circuit that can make it malfunction. > > Bob > > On Feb 9, 2013, at 1:09 AM, Garren Davis <garren.da...@qlogic.com> wrote: > >> >> Well for some reason the 10 Mhz stopped working on the FRK. Don't know why. >> Started up the thunderbolt. It acquired satellites but then the DAC voltage >> went to -5 volts. It's been there for an hour. Will this change after the >> unit stabilizes? Going to bed. Will check it tomorrow. >> >> Garren >> >> >> >> >> On Feb 8, 2013, at 8:25 PM, "Ed Palmer" <ed_pal...@sasktel.net> wrote: >> >>> Hi Garren, >>> >>> I suggest that you get the Thunderbolt working first. Without a known 10 >>> MHz source to compare to, you're flying blind. Once the Tbolt is running, >>> you should be able to check the frequency of the FRK by feeding both into >>> your scope. Trigger on the Tbolt and watch what the FRK does. You should >>> see the trace scrolling in one direction, then slow down, then stop, then >>> scroll the other direction. The 'stop' point is at 10 MHz. The frequency >>> sweeps a total of 20-30 Hz so it's easy to see. If you don't see the >>> 'stop' point, the FRK isn't getting to 10 MHz. Now use the best frequency >>> counter you've got to measure the Tbolt. Regardless of the calibration of >>> your counter, the number your counter gives you becomes your 'new' 10 MHz. >>> Now measure the FRK to see if it's running fast or slow. >>> >>> You should check the temperature of the lamp. It's easy to get at by >>> removing the cover in the center of the heat sink. Probably best to remove >>> the cover and then power down before you go poking around inside! The >>> temperature of the cavity is also important, but getting to it is more of a >>> hassle - don't go there if you don't have to. >>> >>> Of course, check for the normal things like internal power supply voltages, >>> ripple, current drain (both initial and steady-state), etc. >>> >>> Regarding your second message, yes, the adjustment under the heat sink near >>> the edge is the C-field. That won't help you at this point. The >>> adjustment in the center of one side is the VCO. You could try adjusting >>> it, but like I said, you're flying blind at this point. You won't know if >>> you're adjusting closer to 10 MHz or further away. >>> >>> Good luck, >>> >>> Ed >>> >>> >>> On 2/8/2013 6:12 PM, Garren Davis wrote: >>>> Been lurking on the list for a while and finally started playing with a >>>> FRK-L rubidium frequency standard. I've had this thing for a while and >>>> decided to power it up and see what it would do. I do not get a lock. What >>>> I see is the lamp voltage at 8.54 volts which I think is good but the xtal >>>> control voltage swings from 2 volts to 15 volts and back to 2 volts and >>>> keeps cycling like that. I don't have a good frequency counter but I have >>>> a 3 Ghz 40 G/sample scope and it shows that the 10 MHz signal is there. I >>>> just don't know how accurate it is. Has anyone seen a problem like this? >>>> Can anyone point me to a place to start debugging this? I have the >>>> schematics and test tools. I am a test engineer so I'm not afraid to poke >>>> around in the guts of this thing. Hopefully I can get this thing running. >>>> I also have a thunderbolt that I'll get running this weekend. I don't know >>>> how deep I'll get into this time-nuts thing but I have this nice scope and >>>> a Wavecrest sitting in my garage a > n >> d >>> I'd lik >>> e to put them to use. Any help would be appreciated. >>>> >>>> Garren >>> >>> _______________________________________________ >>> 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. >>> >> >> ________________________________ >> >> This message and any attached documents contain information from QLogic >> Corporation or its wholly-owned subsidiaries that may be confidential. If >> you are not the intended recipient, you may not read, copy, distribute, or >> use this information. If you have received this transmission in error, >> please notify the sender immediately by reply e-mail and then delete this >> message. >> >> _______________________________________________ >> 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. > > _______________________________________________ > 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. > ________________________________ This message and any attached documents contain information from QLogic Corporation or its wholly-owned subsidiaries that may be confidential. If you are not the intended recipient, you may not read, copy, distribute, or use this information. If you have received this transmission in error, please notify the sender immediately by reply e-mail and then delete this message. _______________________________________________ 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.
