[Ron Ramirez]

http://www.philcoradio.com/tech/images/90b.jpg

Part (31) on the schematic linked above. It contains two .01 uF caps and one .015 uF cap.

The tone switch has four positions:

1 "Brilliant" - None of the caps are in the circuit.
2 "Bright" - The .015 uF cap is in the circuit.
3 "Mellow" - The .015 cap is now in parallel with one .01 uF cap, giving a total of .025 uF (remember, capacitor values add in parallel).
4 "Deep" - All three caps are now in parallel, giving a total of .035 uF from 47 plate to ground.

How to connect?

Looking at the back of your tone control switch, there should be three terminals. You will be doing this work from right to left so the switch works correctly when you put it all together.

Get a .015 uF 630V film cap, and two .01 uF 630V film caps.

Twist the three leads of only one end of each of the caps together. You will solder a wire to this junction which will go to the plate of the 47 tube. After soldering, insulate the joint with heat shrink tubing as it carries high voltage from the 47 plate.

Leave the other three leads of the other ends of each cap alone for now.

Now, you will need to lengthen at least two, and possibly all three, of these loose leads. Do so by splicing bare solid wire (20 gauge will work, 22 is better) to each one of your three loose leads. Cover each with black heat shrink tubing after soldering so they retain original appearance and will not short to anything.

Okay -

Now you want to connect those leads to the terminals on the tone control switch.

Working from right to left as you look at the back of the switch, attach the loose lead of the .015 uF cap to the first terminal on the switch. Solder it.

Now take the loose lead of one of the .01 uF caps and solder it to the second terminal on the switch.

Finally, solder your last loose lead (the other .01 uF cap) to the third terminal (first one on the left).

Carefully tuck the three caps into the well in the tone control switch (you did remove the original tar baby, right?) making sure no wires are touching the assembly if it is metal. Early tone controls are Bakelite and you don't have this worry. Anyway...put the three caps in, fill the space with hot glue, set aside to let it cool, and you're finished. Reinstall the switch in the radio and connect the wire to the plate of the 47 tube.

And that's all there is to it.

So remember...if the women don't find you handsome...they should at least find you handy.