It's possible that the meter is "off" until you push the Depth of Field Preview (Meter On) switch on the Spotmatic F.
I don't have any Takumar's (robbed long ago). But with no lens on my Spotmatic F, I get meter needle all the way to the top - the meter off state. When I move the "Aperture" slider in the body, the meter comes on and responds. This is expected "Always On" mode of the SMCT lens.
A Takumar or Super Takumar lens will not move the "Aperture" slider. The meter will not be on until you turn on the Depth of Field Preview switch.