The following is a revised AL-80B power supply board schematic. It also applies to all amplifiers in the AL80 mainframe with suitable changes in R106 and R107:
J101 pin outs CCW from top view at index:
| 1 | (-) meter plate current |
| 2-6 | ground |
| 7 | +12V |
| 8 | antenna relay from STBY-OPR switch |
| 9 | high voltage metering, 1 mA = 3500V |
| 10 | ALC out |
| 11 | ground |
| 12 | grid meter (+), plate current meter (-) |
| 13 | -12V |
| 14 | reflected power |
| 15 | forward power |
| 16 | +12V |
C101 is SWR compensation on bypass. Value can change.
C106 is release time for auto-bias. See EBS electronic bias page for circuit description.
Additional revised schematics will appear on this page.