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SVETLANA TECHNICAL DATA
KT88
ELECTRON DEVICES
Svetlana
43mm
51mm
84mm
103.5mm
117mm
KT88
High Performance Audio
Beam Power Tetr ode
he Svetlana™ KT88 is a glass envelope beam power tetrode. It is intended for
audio frequency power amplification service. High plate dissipation rating,
T
close manufacturing specification tolerances and thorough processing pro-
vides improved reliability and superior sonic performance.
The Svetlana KT88 is manufactured in the Svetlana factory in St. Petersburg, Russia,
and is designed to be a direct replacement for any KT88, KT90, KT99 or 6550.
The new KT88 features greatly enhanced sonic performance: Increased peak cathode
emission from new cathode materials; Stable operation from extended processing and
aging; Gold-plated grid; New tri-plate anode; Single-piece beam forming electrode;
Precise grid/screen alignment; Improved vacuum processing; comprehensive static
and audio amplifier testing before and after aging.
Characteristics
Electrical
Heater: Min. Nom. Max.
Voltage (AC or DC) 5.7 6.3 6.9 V
Current 1.6 A
Cathode: Oxide-coated, unipotential
Cathode-to-heater potential, max. -250*/250** V
Direct interelectrode capacitances***
Grid no.1 to cathode and grid no.3, grid no.2,
base sleeve and heater 16.0 pF
Plate to cathode and grid no.3, grid no.2,
base sleeve and heater 12.0 pF
Grid no.1 to plate 1.2 pF
Mechanical
Operating Position Any
Base Large wafer octal 8-pin with metal sleeve
Nominal dimensions:
Height 117 mm (4.61 in.)
Seated height 103.5 mm (4.08 in.)
Diameter 51 mm (2.0 in.)
Cooling Convection cooled
Envelope Temperature (max) 250˚C
Approximate net weight 90 g (3.0 oz.)
*Max with heater negative to cathode **Max with heater positive to cathode
***Without external shielding
AF Power Amplifier
Maximum ratings
DC plate voltage 800 V
Grid no.2 DC (screen) voltage 600 V
Grid no.1 (control) voltage -300 V
DC cathode current 230 mA
Plate dissipation 42 W
Grid no.2 (screen) dissipation 8 W
Svetlana Outline drawing
Svetlana
ELECTRON DEVICES
Headquarters:
8200 South Memorial Parkway
Huntsville, AL 35802
USA
Phone: 256 882 1344
Fax: 256 880 8077
www.svetlana.com
Marketing & Engineering:
3000 Alpine Road
Portola Valley, CA 94028
USA
Phone: 650 233 0429
Fax: 650 233 0439
10/99
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ELECTRON DEVICES
Svetlana
Svetlana KT88
PLATE VOLTAGE (Ep,V)
PLATE CURRENT (Ip, mA)
0
250
400
300
200
100
0
500 750 1000 1250
+10
Eg = 0V
-10
-20
-30
-40
-50
-60
-70
-80
-100
-120
-140
Plate Current
S
vetlana KT88
Typical Performance Curves
Triode Connection
High Performance Audio
Beam Power Tetrode
Typical Operation Class A1 (single tube)
DC plate voltage 400 V
Grid no.2 DC (screen) voltage 225 V
Grid no.1 DC (control) voltage -16.5 V
Peak AF grid no.1 (control) voltage 16.5 V
Zero-signal plate current 87 mA
Max signal plate current 105 mA
Zero signal grid no.2 (screen) current 4 mAdc
Max signal grid no.2 (screen) current 18 mA
Transconductance 11.5 mA/Volt
Signal output 19 W
S
400
Eg = 0 V
-5
vetlana KT88
Typical Performance Curves
s
V
V
0
0
3
=
n
e
e
r
c
Plate Current
300
200
100
PLATE CURRENT (Ip, mA)
200
150
100
PLATE CURRENT (Ip, mA)
50
0
0
0
0
250
250
500 750 1000 1250 1500
PLATE VOLTAGE (Ep, V)
+5
500 750 1000 1250
PLATE VOLTAGE
-10
-15
S
vetlana KT88
Typical Performance Curves
V
e
e
r
c
s
Eg = 0 V
n
=
(Ep,V)
0
4
1
Plate Current
-5
V
-10
-15
-20
-20
-30
-25
-40
-35
400
300
200
PLATE CURRENT (Ip, mA)
100
screen current at
0 V grid voltage
0
0
PLATE VOLTAGE (Ep, V)
255
SCREEN VOLTAGE (Ep, V)
S
vetlana KT88
Typical Performance Curves
Eg = 0 V
100
295 335 375 415 455
-5
-10
-15
200 300 400 500
Ultralinear Connection, 40% taps
-20
-25
-30
Plate Current
Screen Current
-35
-40
-45
-50
-55
-60
www.svetlana.com