Röhren mit Nummernbezeichnung von 1000 bis 4999

4673 special valve, historic type for radio and test gearFor spare lists, vintage service and workshop cross-checkingUse only with equipment notes, cross lists or test dataSocket and heater data omitted without safe quick verification

4066 electrometer tube Uf 1.25V If 0.013A directly heatedUsed in electrometers, measuring amps and high-impedance stagesSuited for test gear, service and special applicationsSocket subminiature B8D with wire leads

Octal K8A 8-Pin base , Top Cap

1684 double triode = 2033 = 1664 Uf 6.3V If 0.3AUsed in RF, VHF and fast signal stages of special equipmentSuited for IBM, test gear and historic electronics serviceSocket Pico7 B7G 7-pin miniature tube without top cap

1645 photocell = 5652 for light sensing and modulator stagesUsed in facsimile, scanning and optical signal processing gearSuited for restoration, service and rare special equipmentSocket Octal K8A 8-pin special tube without heater

1643 triode Uf 2V If 0.82A for telephony and AF stagesUsed in telephony, historic signal paths and special repairsSuited for vintage equipment, service and rare tube lineupsSocket Europe B4 4-pin directly heated without top cap

1635 double triode Uf 6.3V If 0.6AUsed in class-B drivers, AF stages and special equipmentSuited for test gear, service work and rare tube lineupsSocket Octal K8A 8-pin glass tube without top cap

close to 12SC7

1625 transmitting pentode = VT136, 807-related, Vf 12.6VFor RF finals, transmitters, modulators and strong driversSuited to ham radio, military radio, service and spare stockSocket Septar 7-pin, anode cap, power pentode

UX5-UY5 tube base with 9mm Topcapclose to 1619, 807

Octal K8A 8-Pin basesimilar to 6F6

1612 heptode Uf 6.3V If 0.3A for control and mixer stagesUsed in expander, compressor and special signal circuitsSuited for test gear, service work and rare applicationsSocket Octal K8A 8-pin glass tube with 6mm top cap