why does channel selector work even when switch falls off?

[newnewulm]

while fixing an atari i notice the channel selector switch "slide" had fallen off, without the switch I think the atari is on channel 3 even though no connection through the slide is being made - - - why? on the switch there are 3 wires going in to the slide area, so i would think the slide connects 2 of 3 wires at a time however I am puzzled why channel 3 is being selected and sent signal even though the slide isn't connecting any paths (i would think this is a break in signal).

 

does the absense of a connection make the atari treat channel 3 as the target and therefore modify its signal accordingly? if so, how. is there any benefit to actual cutting off the metal that presents the channel 2 option thereby maybe increasing the signal power to channel 3?

 

any smart people know how this part of the atari works and whether it's worth futsing with it to get a stronger signal? thanks