10-02-2008, 04:51 PM
Starting to partially restore to operating condition a Model 70 . I replaced the filter caps and the coupling cap to the audio tube and realigned the set. All tubes test good. It now has very good sensitivity and selectivity but the volume could be much better. Seems that when I touch the volume control , the R.F.grid or the ant. clip, the volume almost doubles.
When I test voltages the screen grid volts are about one and a half times what they should be -- the control grids are about five times what they should be!! -- Cathode volts are about one and a half times . The even stranger thing is that the " 24 " second detector plate has over the double ( 230 v. ) what it should be!! The other plates are only sl. high.
The large w/w resistor tests O.K. Even with all these all these problems the set plays reasonably well! --- anybody know whats going on here????
Tom
When I test voltages the screen grid volts are about one and a half times what they should be -- the control grids are about five times what they should be!! -- Cathode volts are about one and a half times . The even stranger thing is that the " 24 " second detector plate has over the double ( 230 v. ) what it should be!! The other plates are only sl. high.
The large w/w resistor tests O.K. Even with all these all these problems the set plays reasonably well! --- anybody know whats going on here????
Tom
