Repair: Difference between revisions

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Here is a photo of the taped-up schematic, with my annotations and some flags showing the components I decided to replace:
Here is a photo of the taped-up schematic, with my annotations and some flags showing the components I decided to replace:
[[File:Schematic_indicating_replacements.jpg|500px|thumb|center]]

Revision as of 22:05, 21 May 2020

I printed the schematics, figured out how to remove the Relay Shelf, and began:

30s1 relayshelf halfout selfie.jpg
  • Bias Transformer T203 was utterly toasted... burned and bubbled. Fortunately Peter Dahl / Hammond offer a top-quality replacement - Whew! Nearby components and the wiring-harness appeared miraculously undamaged!
  • Bias rectifiers had been changed to silicon diodes, mounted on a terminal-strip. However, the terminal-strip was bent over, shorting at least one (perhaps two) leads to the chassis.
  • In a similar vein on the underside of the Relay Shelf, Bias divider resistor R218 was bent to touch the chassis
  • Next to this bent/touching resistor, I then saw the cracked-and-broken 10-ohm R232 (limits screen-supply inrush current).
  • And, the RF output connector had been changed from the N-flanged original, to a loose-and-sloppy SO-239 barrel (featuring mangled threads which prevented tightening).
  • Time-delay thermal relay K202 was only 35-seconds, not 3-minutes as Collins designed (to ensure V101's cathode is properly heated before use).
  • Rectifier-filament transformer T202 had cracked-and-broken secondary leads. Because this amplifier had replacment solid-state HV rectifiers, I decided to simply remove the no-longer-needed T202.

Here is a photo of the taped-up schematic, with my annotations and some flags showing the components I decided to replace:

Schematic indicating replacements.jpg