[Hallicrafters] SX-16/17 Vol Control Question

[Wj5mh at aol.com]

I'm slowly working through my SX-16, and I'm about to replace the volume 
control.  I've noticed that this pot is a strange bird.  It appears to be a pot 
with a normal wiper, but it also has a fixed tap at midpoint that runs through a 
resistor to the tone control.

The schematic shows 1 meg., but someone has replaced it with a 250K, so if 
you measure resistance between the tap and the wiper, the resistance will go 
from 125K through zero and back to 125K as the control is turned from one extreme 
to the other as expected.

I've never seen one of these, and chances of finding one are probably nil, so 
if you have replaced your volume control, how did you get around this special 
pot?  Did you just connect the resistor going to the tone control to the 
wiper of the volume control?

What the heck is this type of pot called, anyway?

Thanks,
Joe