> My reprint of the manual has an asterisk by R6, but the note isn't there > (I suspect I have some missing pages). The schematic around the mode > switch is a bit of a rat's nest to follow, but it looks like there's > 100k across the 12M R6 in normal mode, while in LTC mode R6 by itself > works against the 8uF C8.
Ah, interesting -- that note appears in the series 1248 manual (Feb 73) but not the series 1740 (June 1978). It shows up on the bottom of both figure 8-2 (page 8-3) and figure/page 8-5. That's why you won't find it in the online 5061A manual (series 1740A). PHK is also correct that what is C8 in some units is C2/C3 in others. Maybe it's time to put the manual aside and open it up to have a look. > The note seems only to apply to the high performance tube option. I > wonder if it's not called out for standard unit because there's > something different in the circuit, or just because the shift is within > spec for the normal tube? The 2E-12 is pretty similar to what I saw > when I made the switch. That was my guess too; the standard unit isn't good enough for this to matter much. I think the option 004 tubes are also the only ones with the degauss option. Note also that older 5061A didn't have a LTC position on the mode switch. /tvb _______________________________________________ time-nuts mailing list [email protected] https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
