Description

KT88-TII is a beam power tetreode, its anode limited dissipation power is 42W. In the audio amplifier, the power can be 100W when it is used as push-pull class AB1 with double tubes, it can also be used in electronic voltage regulator circuit. KT88-TII is similar with CV5220 and 6550,they can be replaced by each other.

Heater
Uf ……………6.3 V
If…………………………1.6 A
Maximum Rating
Ua……………………800 V
Ug2………………600 V
Ug1………………-200 V
Pa………………42 W
Pg2…………8 W
Ua+g2…………46 W
Ik……………………230 mA
Uh-k……………200 V
Tbulb…………………250 C
Rg1
with cathode bias
Pa+Pg2≤35W 0.47 MΩ
Pa+Pg2 > 35W 0.27 MΩ
with fixed bias
Pa+Pg2≤35W 0.22 MΩ
Pa+Pg2 > 35W 0.10 MΩ

Direct Interelectrode Capacitances
tetrode connection triode connection
input………16 9.3 PF
output ……… 12 17PF
grid to plate………1.2 7.9 PF

tetrode connection
Ua…………………… 250 V
Ug2……………………250 V
Ia ……………………140 mA
Ig2(approx) ………3 mA
-Ug1(approx)………15 V
Gm ……………………12 mA/V
ri ……………………12 KΩ
Ug1-g2……………… 8
ri ……………………670 Ω
u………………………8

triode connection
Ua.g2…………………250 V
Ia+g2…………………143 mA
-Ug1(approx)………15 V
Gm ……………………12 mA/V