813 / FU-13 Transmitting tube, 500 watts Beam Power Pentode
[NN633]

813 / FU-13 Triode, aka: QB2/250, CV177, 4T100, VT144, CV26

suitable socket available here: : S7C-A

Recomendations for 813 / FU-13 Transmitting tube, 500 watts Beam Power Pentode: HiFi Triodes, Transmitting Tubes [NN638C] 833C Power Triode, Transmitting tube with graphite anode 833C Transmitting tube with graphite anode (socket not included) power up to 1800 Watts with forced air cooling matching sockets: s2-833 +  2x sPC14 Specification: Anodevoltage (max.): 4000V... 118,00 Euro