Sir Ralph Ceeeeeee. . . . .
In your eye tube "dilating", are you RAT sure of that action . . . . but who is to say as "I don't know nothin' 'bout birthin' no babies " . . .hi hi.
Now, in referencing your units schematic . . . . ( a la bottom :)
Check the most suspect parts associated with the tuning eye ancilliary wiring, in the respect of that RED boxed R14 resistor and is companion C38 capacitor .
Absolute, almost zero leakage is required on that capacitors spec in order to maintain the level of that high impedance . . . . (easily loaded DOWN ) . . . negative AVC buss voltage.
Also check the tolerances of the FUCHSIA marked resistors on the AVC buss (GREEN).
There are also some low picofarad valued decoupling capacitors off that buss, but are typically not found suspect.
Initial Exploratory Test:
Be sure that your set is in its Ferrite Loop antenna position versus its external antenna input position.
I . . . think? (Alzheimers) . . . that is related to the TA-TB associated pushbuttons on your Grunt -Diggg.
Easy confirmation of that is to tune in a weaker received station and multi finger grasp the windings of that Ferrite rod anenna and see if it either detunes it or improves reception, the latter effect should show with a tuning eye deflections / closures improvement.
If no improved results, you might tune into a strong station and hook up DC metering with ground referencing and expect to be reading a negative voltage across C38 to use as a referencing test point.
Note that when you tune into a station the negative voltage level increases and peaks and the falls of when tuning on past the station.
Now if you want to experiment, locate the blue box marked up I.F. transformers and put the set in BCB band and tune onto and peak on a stronger station. Peak for max reading.
Then, take note of your adjustment tools initial position on ONE of the 4 possible coils that are being available between the 2 IF transformers.
If your negative voltage increases, the condition should also show by more closure of the tuning eye. Peak and move on to another coils adjustment. Only minor adjustments will usually be needed.
Standing by . . . .
ASIDE. . . . .
Pee Ess . . . .forgive my old cat as he's getting on 12 years old and has lost some paw "motor dexterity", in precise assistance.
But I wouldn't take for him, what other CAT can "SIT" on command and then "SHAKE"(paw/hand) on command.
And that's along with him hearing my trucks "Smittys" whenever I turn onto either end of the block, with him then bursting out at break neck speed, until meeting it and then trotting on alongside 'til reaching the house.
73's de Edd