Amperex 805 vacuum tube (JAN-CEP-805) power triode. I’ve marked this “tested”, and you might reasonably ask, “How?” I bodged up a simple rig to hold a socket and 10V filament transformer to get the tube lit. I then applied plate voltage from a bench power supply, while varying the grid voltage with a second supply. My plate supply is limited to 500 volts, but the Amperex tube data goes down that far, and it is possible to read the change in plate current with grid voltage (transconductance) from the plate characteristics chart: at Vp = 500V and Vg near 0V, transconductance is about 4mS. My measurements: at Vg = 0, Ip ~ 22mA, and at Vg = +10V, Ip ~ 65mA, which indicates Gm ~ 4.3mS, very close to the Amperex data.
Item Tag: 805
Amperex 805 Vacuum Power Triode — Tested!
Amperex 805 vacuum tube (JAN-CEP-805) power triode. I’ve marked this “tested”, and you might reasonably ask, “How?” I bodged up a simple rig to hold a socket and 10V filament transformer to get the tube lit. I then applied plate voltage from a bench power supply, while varying the grid voltage with a second supply. My plate supply is limited to 500 volts, but the Amperex tube data goes down that far, and it is possible to read the change in plate current with grid voltage (transconductance) from the plate characteristics chart: at Vp = 500V and Vg near 0V, transconductance is about 4mS. My measurements: at Vg = 0, Ip ~ 22mA, and at Vg = +10V, Ip ~ 65mA, which indicates Gm ~ 4.3mS, very close to the Amperex data.
Related Images:
NU NATIONAL UNION Type 805 Amp TRIODE Transmitting VACUUM TUBE Tested V.9185
Tube Type Triode. Common Use Transmitting. ALL TUBE AUDIO. Tube Specifications. Plate Graphite. Why Buy From All Tube Audio?. Condition STRONG Tested. Tested using s special built aparter for HICKOK TESTERS.
Related Images:
National Union 805 VINTAGE Radio TRANSMITTING VACUUM TUBE NOS Tested 1.7703-D
TRANSMITTING TYPE TUBE. National Union 805. RADIO VACUUM TUBE. Black Plate. TESTED on HICKOK TV-7.
Related Images:
1 x RCA 805/VT143. Used, test strong (Labeled as Amperex)
1 x RCA 805/VT143. Used, test strong. (Labeled as Amperex). Test results. Test result is for reference only. Ia : 70mA (127%). Plate: 1000v.
Related Images:
GREAT PAIR CETRON 805 VT 143 Amplifier Vintage VACUUM TUBES Tested ! V.8972
NICE PAIR CETRON 805. 805 VT-143. Amplifier Power Tubes. Date Codes = 79-19 (both tubes). TESTED on HICKOK TV-7. Using Special Built Adapter. Bottom OO Getters.
Related Images:
1 x RCA 805/VT143. Rare dual getter from the late 30’s. Used, test strong
1 x RCA 805/VT143. Rare dual getter from the late 30’s. Used, test strong. Test results. Test result is for reference only. Ia : 53mA (96%). Plate: 1000v.