KT88 DIAMOND

CHARACTERISTICS

Plate dissipation ( Max.)		40 W
Grid dissipation ( Max.)		6 W
Cooling		radiation
Heater: Voltage		6.3 V
Heater: Current		1.6 A

MAXIMUM RATINGS

Anode voltage		800 V
Screen grid voltage		600 V
Va, g2		600 V
- Vgl		200 V
Pa		35 W
Pg2		6 W
Pa + g2		40 W
Ik		230 mA
Vh -k		200 V
Tbulb		250 °C

CAPACITANCES ( measured on a cold unscreened valve)

Triode connection Cgl -a, g2   7.9 pF Cg1 -all less a, g2   9.8 pF Ca, g2 -all less g1   17 pF

Tetrode connection Cg 1 -a   1.3 pF Cg 1 -all less a   17 pF Ca -all less g1   12 pF

Push - Pull, Class AB 1, Cathode Bias, Ultra - Linear Connection ( 40% Tapping Points).

Vag2 (b)		500		375 V
Vag2 (o)		436		328 V
Ia + g2 (o)		2 x 87		2 x 87 mA
Ia + g2 ( max. sig)		2 x 99		2 x 96 mA
RL ( a-a )		6		5 k Ohms
* Rk		2 x 600		2 x 400 Ohms
- Vg1 ( approx. )		52		35 V
Pout		50		30 W
Dtot		1,5		1 %
I.M.D.		4		3 %
Wa + g2 (o)		2 x 38		2 x 28.5 W
Wa + g2 ( max. sin)		2 x 17		2 x 16 W
V g1 - g1 ac		104		71 V
Zout		4.8		4.5 k Ohms

*It is essential to use two separate cathode bias resistors. I.M.D. intermodulation distortion measured using two input signals at 50 and 6000 Hz ( ratio of amplitudes 4:1)
Push - Pull, Class AB 1, Cathode Bias, Triode connection.

Vag2 (b)		400		485 V
Vag2 (o)		349		422 V
Ia + g2 ( o)		2 x 76		2 x 94 mA
Ia + g2 ( max. sig )		2 x 80		2 x 201 mA
RL (a - a)		4		4 k Ohms
-Vg1 (approx. )		40		50 V
Pout		17		31 W
Dout		1.5		1.5 %
I.M.D.		5.6		5.6 %
Wa + g2 (o)		2 x 26.5		2 x 40 W
Wa + g2 ( max. sin)		2 x 29		2 x 27 W
V g1 - g1 ac		78		114 V
Rk		2 x 525		2 x 525 Ohms
Zout		4.8		4.5 k Ohms

I.M.D. intermodulation distortion measured using two input signals at 50 and 6000 Hz ( ration of amplitudes 4:1).