AK Model 42 Transformer Ground?

[Winky Dink]

Of course I know how a variac works. You turn that knob on the top and watch the needle go up....
But seriously, I tried to research this earlier but I needed that word, "AUTOtransformer."
Thanks much.

[Winky Dink]

I'm at the point where I'm repeating tests without changing anything and expecting different results. The only change I've made is to increase the plate voltages which were all lower than normal. This made a very slight change in the radio's performance.

These socket voltages look good to me:



Still, I can only pick up a broadcast signal if it's very strong and the antenna post is connected to my "earth ground." With the radio's lid on the output is medium-low audio volume at the rheostat's lowest, increasing as expected when the volume is turned up, like half the signal is going through the rheostat. But if I pull the coupling tube, there no appreciable change in the audio output.

On the other hand, if I use a signal generator (induction through two loop antennae) to the antenna post, then pulling the coupling tube stops the audio output.

I've also tried aligning the variable condensers but haven't changed anything. Notably, rotating the antenna coupling condenser 360 degrees has no effect on the output.

I'm hoping that these results will resonate with someone. Otherwise this set goes back in the box and I move on to the next project ("Going from failure to failure with undiminished enthusiasm").

https://lh5.googleusercontent.com/-C...42%2520901.JPG