tesla RE 40 AK, KT 88 DATASHEETS

TESLA RE 40 AK / KT 88

BEAM TETRODE manufactured by Tesla Vršovice s.r.o. Czech Republic

Brief data

The RE 40 AK has a designed maximum anode dissipation rating of 35 W and
is recommended for use in the output stage of an a.f . amplifier. Two valves in
class AB1 gives a continuous output of up to 100W. The RE 40 AK is also
suitable for use as a series regulator valve in stabilized power supply.

The RE 40 AK is a commercial version of the KT 88 and is similar to the 6550.

vacuum tube data sheet

Heater

Vh 6,3 V
Ih 1,6 A

Maximum ratings

Va 800 V
Vg2 600 V
Va, g2 600 V

-Vg1 200 V
Pa 35 W
Pg2 6 W
Pa+g2 40 W
Ik 230 mA
Vh-k 200 V
Tbulb 250 °C

A hand written test report

Capacitances, triode connection

Cg-a, g2 7,9 pF
Cg-all, less a, g2 9,8 pF
Ca, g2- all less g1 17 pF

Capacitances, tetrode connection

Cg-a 1,3 pF
Cg-all, less a 17 pF
Ca, g2- all less g1 12 pF

Base: metal shell wafer octal
Pin 1 base shell 5 g1

2 h 6 ­3 a 7 h
4 g2 8 k

Dimensions are in mm and are maximum.

Installation

It is recommended to mount the tube
vertically. In this position should be the
tube sockets not less than 4 inches apart
and pins 4 and 8 of each tube in line.
Free air circulation around the tube is
necessary for sufficient cooling.

Push-Pull, Class AB1, Cathode Bias, Ultra Linear
Connecion (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 kΩ
*Rk 2 x 600 2 x 400 Ω

-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.sig) 2 x 17 2 x 16 W
Vg1-g1 ac 10 4 71 V
Zout 4,8 4,5 k Ω

* It is essential to use two separate cathode bias resistors. I.M.D intermodulation distrortion measured
using two input signals at 50 and 6000 Hz (ratio of amplitudes 4:1).

Retail sales agent: Importer:

Push-Pull, Class AB1, Cathode Bias, Triode
Connecion

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 101 mA
RL (a-a) 4 4 kΩ
Rk 2 x 525 2 x 525 Ω

-Vg1 (approx.) 40 5 0 V
Pout 17 31 W
Dtot 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.sig) 2 x 19 2 x 27 W
Vg1-g1 ac 7 8 1 14 V
Zout 4, 8 4 ,5 kΩ

vacuum tube data sheet

TESLA RE40AK / KT 88