So I'm in the middle of recapping and recalibrating a pair of HP 410Bs and there seems to be a discrepancy between one version and the other. The first one is serial number 4421 which has line filters as well as an extra 50uF electrolytic somewhere between wafers. The second one follows the schematics (serial 29925).
Interestingly enough the manual does make reference to C13 between wafer S1G and S1F, though there's no listed value. (I can only assume C11 and C12 are the line filters.) They also removed the tube shields off of the 12AU7s.
I guess HP figured eliminating those components didn't cause too much harm in later versions. Should I remove them (caps) entirely or simply replace them?
Here's the schematic to which I'm referring.
http://hparchive.com/Manuals/HP-410B...prefix-024.pdf
EDIT
Also, the single electrolytic that is in the first unit is 0.5uF instead of the listed 4uF