Re: Early 577 service manual needed.


 

Production serial numbers started at B010101, so B010124 is a production instrument, just a very early one. The suffix on the CRT part number designated different phosphors and graticule types. The preferred graticule for a 577 is 10x10 1 Cm centered horizontally. There is also a variant of this CRT that has an 8x10 1.25 CM graticule. Usable, but not the best. There is also probably a variant of this CRT with no graticule. Check the 154- RPR's on the vintageTEK website.

If by "dialing in the amps" you mean the vertical sensitivity on the higher-current ranges is wrong, check the high-current shunts, which are on a board plugged into circuit board in the 177 adapter. It's a piece of thin PCB material with scribe lines to adjust the resistances.



--
Bob Haas

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