Description

KT88 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 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