SEVEN lead dual pot?

[solis365]

I have stolen an audio taper pot from a casette recording unit from the early 90s. It is a 100k log pot but there are 7 leads. Six of the leads are easily identifiable as the two potentiometers but the 7th seems to have a fixed resistance between it and some of the other leads.

any idea what its for?

 

[colin55]

Is it an earthing lead or shield?

 

[mneary]

Is there an LED in the knob?

 

[solis365]

There is no LED anywhere. What is the best way to tell if its a shielding lead? this makes sense since its an audio pot. The seventh lead isn't obviously connected to the metal housing, and the housing doesnt encase the entire device anyway. It is mostly blue plastic (but its not one of the blue bournes trimpots)

 

[mneary]

the 7th seems to have a fixed resistance between it and some of the other leads.

I suppose you aren't going to tell us unless we ask: What is the resistance value from the 7th lead, and to which others does it connect? Is the pot single shaft, or concentric shafts one for each pot?

My next guess is that it's a concentric pot. One is the recording control with fixed frequency response, and the other is the playback control with a 'loudness' tap.

What do I win?

 

[solis365]

i have been reluctant with details as i have been away from my desk. however, now I have it and a multimeter right in front of me.

It appears as though the 7th lead is an open circuit to the rest of them. I must have bridged a connection before.

perhaps it is only there since the package width is as wide as seven 0.1" leads and not six? just a simple "NC" deal on the datasheet i presume, if I could find one (no part number)

Thanks for the help anyways, it appears to be a moot point. :/