[Tubester]

Still not clear on the wiring interface between the 6A7 and oscillator. After refering to the available schematics and service bulletins, my unit lacks some of the updates. Service bulletin 217B says to remove resistors #17 (51k for BC and #18 (25k for SW) between the oscillator secondarys and tube cathode. I assume that means after removing them to tie the wires from the oscillator to the cathode of the 6A7? Has anyone done this? Also, the same bulletin says to add a 20 ohm resister between the 6A7 cathode and ground. Has anyone done this? Was there any noticeable improvement? Also the same bulletin says to add a 35k resistor to the switch 1 terminal side of #7 capacitor to ground. Anyone done that? And finally, I still am unclear regarding the wiring of the short wave section of the oscillator. Can anyone identify which solder tabs at the bottom (and the wire coming from the top) are across the 0.5 ohm primary and 0.1 ohm secondary sides? Also, which tabs are tied together that go to the 2250 pf and #13 trim nut for the compensating condensor. In the OBTW section, just pick up a working NRI 70 tube tester. I have a few weak tubes to replace. Thanks, Dan