07-11-2011, 08:55 PM
HELP!!!!! I got back to this radio today with the idea that I would attempt an alignment as suggested by Raleigh. I did not do anything to it since my previous post. Much to my dismay the radio would not receive any stations as it did previously. Not knowing where to go next I dropped the attempt to try an alignment and decided to measure voltages to compare with the design values and report them here with the hope that someone can head me in the right direction. There are two XXL tubes and two 41 tubes in this radio. Values are shown by tube number with the design value followed by the measured value.
XXL PLATE 125 152
XXL PLATE 85 113
7V7 PLATE 187 205
7V7 GRID 75 147
7V7 PLATE 190 208
7V7 GRID 125 150
XXFM PLATE 87 133
41 PLATE 185 203
41 GRID 173 208
41 PLATE 185 205
41 GRID 190 198
Filament voltages are 6.6.
Additionally I measured the voltage across the electrolytic caps. I replaced the 18 mfd with a 22 mfd and the two 8 mfd caps with 10 mfd. Voltages are:
22 mfd, design - 290, measured - 296
10 mfd, design - 135, measured - 160
10 mfd, design - 190, measured - 208
Thanks, Bob
XXL PLATE 125 152
XXL PLATE 85 113
7V7 PLATE 187 205
7V7 GRID 75 147
7V7 PLATE 190 208
7V7 GRID 125 150
XXFM PLATE 87 133
41 PLATE 185 203
41 GRID 173 208
41 PLATE 185 205
41 GRID 190 198
Filament voltages are 6.6.
Additionally I measured the voltage across the electrolytic caps. I replaced the 18 mfd with a 22 mfd and the two 8 mfd caps with 10 mfd. Voltages are:
22 mfd, design - 290, measured - 296
10 mfd, design - 135, measured - 160
10 mfd, design - 190, measured - 208
Thanks, Bob