01A Silvertone, St Envelope, New Boxed 201A, D401A, 201, ER201A, C509A, C509, 301A, VT-30, DC201A, CV750, 401A_UX, LS201A, FX201A, CX201A, X-201A, 4600, RH201A, MX201A, KD01A, LB-201A, D201A, D-201A, EX201A, S01A,
01A SILVERTONE, ST ENVELOPE, NEW BOXD 201A, D401A, 201, ER201A, C509A, C509, 301A, VT-30, DC201A, CV750, 401A_UX, LS201A, FX201A, CX201A, X-201A, 4600, RH201A, MX201A, KD01A, LB-201A, D201A, D-201A, EX201A, S01A,
The 01-A /01A THORIATED FILAMENT /01AA OXIDE COATED FILAMENT is a storage battery triode used as detector or amplifier.
Filament takes 5V @ 0.25A.