http://www.ham-radio.com/wa6vhs/Test%20equipment/FREQUENCY%20STANDARDS/FE-5680A/fei%205680a.pdf has high quality images of the 5680A and 5650A internal electronics.
Bruce >Hi, >some light might be shed on the heatsink problem by reading the data >sheet for the LPRO 101 (Symmetricom) >The units will have similar issues to cope with. >The LPRO has temperature controlled lamp and filter, at different >temperatures above 80C. >Its power consumption is shown in a chart and is reduced as the >temperature rises because the heating power needed becomes less. >It must have a 17V internal series regulator, because total power >consumption falls down to the minimum of 18V. >MTBF is listed as 380kh at 20C, 320kh at 30C, 253kh at 40C, 189k at >50C and 134k at 60C. >These are values that you would expect for most solid state boards. >My solution was to put the device onto a finned heat sink in an >aluminum box with a tiny 12V brushless fan, (40mm) >which runs on 8 volts and is switched by a thermistor in the heatsink >to keep the baseplate at 40C. >This seems to be a good trade-off with MTBF, and the 10 MHZ xtal will >run at a constant temperature of 40C + or - 0.05. >I have not yet assembled the gear to measure how much its performance >is improved. >cheers, Neville Michie > > >On 09/06/2009, at 2:18 PM, Mark Sims wrote: > >> >> >> Also see my post from June of last year where I had measured the >> heat sink rise over ambient of several rubidium oscillators in free >> air... the FEI-5650 was very close to it's operating limit if >> operated in free air and not attached to something: >> http://www.febo.com/pipermail/time-nuts/2008-June/031695.html >> >> _________________________________________________________________ >> Lauren found her dream laptop. Find the PC that’s right for you. >> http://www.microsoft.com/windows/choosepc/?ocid=ftp_val_wl_290 >> _______________________________________________ >> 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. _______________________________________________ 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.
