AAAAh hahhhh . . . With that 12K being transposed in the past with a 20 k that disrupted the situation in two ways. |
I changed R14 with a 14K resistor, which had at some point previous been replaced with 20K wire wound resisitor. Now reading 287 volts on plates and about 81 volts on screen of 6K7. This seems more reasonable. Likely a 12K resistor as called for, will do the trick.
Brian
Thanks again.
It is still the original speaker intact, and all electrolytics are new. Stations come in good with lots of volume, nice tone, even a few shortwave stations too. That capacitor is deeply buried so I will measure resistors first.
Sir Brian. . . . . .
Ab-so -rootley, on the possibility of C38 leaking and pulling down the Sub B+ level a bit.
What you might try is to monitor the Sub B+ at the origin of its tap off at voltage divider bridge of R14-R17.
Then you unplug 6K8 and 6K7 tubes to see what the sub B+ rises up to without loading . . . Then plug in one tube at a time and recheck the voltage level. One of those individual tubes will have loaded and pulled the voltage down a wee bit more than the other.
I am thinking that it will be ~ 12 ma consumption for the 6K8 and ~11 ma for the 6K7. Seems like C38 is over to the side of the chassis and down under a lip.
That C38 would have to be seriously leaky down in the k's of resistance to be effecting us on that degree of a voltage drop.
The potential other thing aparrent on that supply line, is leakage within the the C41---5 ufd filter , which we hope that you have already replaced with a good unit.
You did not make any reference to the 1k power res sub for a speaker field coil, so I guess that situation was on somebody elses set. And, you also still have the original speaker in your unit, and no one has subbed in a speaker with a lower value of field coil reisistance / inductance.
BTW have you ever heard stations picked on this radio ? That initially being even before you started changing parts, considering that you made an initial g r a d u a l power up, thru a Variac, to see if there were initially any power electrolytic filter issues in the unit.
2 questions included.
Standing by . . .
73's de Edd
