Valve & Amplifier Design, EL34 (6CA7) Data, Mullard Valves

OUTPUT PENTODE

Output pentode rated for 25W anode dissipation,

ntended for use in a.c. mains operated equipment.

PRELIMINARY DATA

HEATERVh

Ih

6.31.5

vA

CAPACITANCES7.2

15.5<1.1<1.0

11

pFpFpFpFpF

Cout

Cln

C&-gl

Cgl-hCk-h

CHARACTERISTICSVa

v go

Vgs

la

Igo

Vgl

gm

ra

(.I.gl-gO

250250

0100

14.9-13.5

111511

vvv

mAmA

VmA/V

kil

OPERATING CONDITIONS AS SINGLE VALVE CLASS "A"AMPLIFIER

Pentode connection

Va 250 VVg2 250 VVga 0 VVg1 -13.5 VRk 120 (1la 100 mAIg2 14.9 mAR. 2.0 k(1V1n (r.m.B.) (Pout=50mW) 0.5 V

*Pout 11 WV1n (r.m.B.) 8.7 V

*Dtot 10 %

*Pout and Dtot are measured at fixed bias and therefore represent thepower output available during the reproduction of speech and music.When a sustained sine wave is applied to the control grid the biasacross the cathode resistor will readjust itself as a result of theincreased anode and screen-grid currents. This will result inapproximately 10% reduction in power output.

ISSUE 2 EL34 256-1

OUTPUT PENTODE

Output pentode roted for 2SW onode dissipotion,

intended for use in a.c. mains operated equiPment.

OPERATING CONDITIONS FOR TWO VALVES IN PUSH-PULL

Distributed load conditions with screen-grid tapping at 43% ofprimary turns

4301

4252 x 62.5

2x652x5.02x5.1

470326.6

200.8

430

1

425

2 x 62.5

2x70

2x5.0

2x7.5

470

52

6.6

37

1.3

vkO

VmAmAmAmA

OV

kOW

%

V"J-VRk

Rg2 (per valve)

Vg2+VRk

18(0)

18 (max. sig.)

Ig2(0)

Ig2 (max. sig.)

Rk (per valve)

V1n(gl-gl) r.m...

R8-8

Pout

Dtot

OPERATING CONDITIONS FOR TWO VALVES IN PUSH.PULL

Fixed bias

4251000

0

2x30

2x120

2x4.4

2x25

-38

3.4

54

55

5.0

375470

0

2x35

2x120

2x4.7

2x25

-32

2.8

45

44

5.0

yOy

mAmAmAmA

ykO

yW%

Vb

"Rg2

Vg2

18(0)

la (max. sig.)

Ig2 (0)

Ig2 (max. sig.)

Vg1

R8-a

V1n (gi-g 11 r.m.8.

Pout

Dtot

*Screen-grid resistor common to both valves,

These operating conditions apply with a stabilised line voltage andallow for a 25V drop in the primary winding of the output trans-former at maximum signal. If there is an additional drop of 25Vin the h.t. line voltage at maximum signal Pout=45W and 36W.The optimum anode-to-anode load under these conditions are4.0kD. and 3.8kD. respectively.

ISSUE 2 EL34 256-2

OUTPUT PENTODE

Output pentode rated forc25W anode dissipation,

intended for use in a.c. mains operated equipment


With separate screen-grid supply and fixed bias

Vb(a) 500 800 VVb(g2' 400 400 V

*Rg2 750 750 !1Vg:J 0 0 VJa(O; 2x30 2x25 mAla (max. sig.) 2x125 2x91 mAIg2(o, 2x4.0 2x3.0 mAIg2 (max:sig.) 2x25 2x19 mAVg1 -36 -39 VRa_a 4.0 11 k!1VIR (g,-g,) r.m.B. 51 47 V

, PC))1~ 70 100 WI Dto1 5.0 5.0 %

,*Screen-grid resistor common to both valves.

These operating conditions apply with stabilised line voltages andallow for a 2SV drop in the primary winding of the output trans-former at maximum signal. If there is an additional drop of 25Vin the line voltages at maximum signal Pout=58W and 90W. Theoptimum anode-to-anode load under these conditions are 5.0k!1and 11 kO respectively.

OPERATING CONDITIONS FOR TWO VALVES IN PUSH.PULL

Cathode biasVb 375 V

*Rg. 470 OtRk 130 OVg. O Vla(ol 2x75 mAla(max.sig.) 2x95 mAIg.(ol 2x11.5 mAIn (max.c5jgr) ! 2 x 22.5 mARa_a 3.4 kOV1n(gl-gl) r.m.8. 42 VPout 35 WDtot 5.0 %

*Screen-grid resistor common tO both valves.

tCommon cathode bias resistor.

These operating conditions allow for a 20V drop in the primarywinding of the output transformer and a 5V drop in the h.t. linevoltage at maximum signal.

ISSUE 2 EL34 1056.3

OUTPUT PENTODE

Output pentode rated far 25W anode dissipation,

intended for use in a.c. mains operated equipment.

"A"OPERATING CONDITIONS AS SINGLE VALVE CLASSAMPLIFIER

Triode connection (g2 connected to a, ga to k)

Va+VRk 375V 0R~a 370la 70Vgl -26Ra 3.0V1n (r.m.s.) (Poul=50mW) 1.7Poul 6.0V1n (r.m.s.) 18.9Dlo1 8.0

vvO

mAV

kOV

WV

%


Triode connection (g2 connected to a, g3 to k)

V,,+VRk 400 430 VV83 0 0 V

*Rk 220 t250 .0I,,(o) 2x65 2x64 mAI" (max. sig.) 2x71 2x67 mAV81 -29 -32 VR"_,, 5.0 10 k.OV1n (81-81) r.m.s. 44 48 VPoul 16 14 WD1o1 3.0 <1.0 %

*Common cathode bias resistor.

tUn-bypassed.

LIMITING VALUES

2.0800

2527.5

800425

8.0150-1.3

70050010020

kV

V

W

W

V

V

W

mA

V

k.Q

k.Q

V

k.Q

Va(b) max.Va max.Pa max.Pa max. (max. signal speech and music)V lI(b) max.VII max.pgo max.Ik max.Vn max. (In=+0.3!J.A)Rn-k max. (cathode bias)Rn-k max. (fixed bias)Vh-k max.Rh-k max.

ISSUE 2 EL34 1056.4

OUTPUT PENTODE

Output pentode roted for 2SW anode dissipation,


~

92 91

HCa

q2

h h

kq3

Oclal Bas,

~EL3~ 1056-5ISSUE 2

OUTPUT PENTODE

Output pentode rated for 25W anode dissiPation,


ANODE AND SCREEN-GRID CURRENT PLOTTED AGAINST CONTROL

GRID VOLTAGE

EL34 1056-6ISSUS;2

OUTPUT PENTODE

Output pentode roted for 25W onode dissipation,


~0-

~I

>"i'

>O

."'"""-' "..."'

::'

>OII

I~,0.:~..

0~~a..

HE

ANODE CURRENT PLOTTED AGAINST ANODE VOLTAGE WITH

CONTROL-GRID VOLTAGE AS PARAMETER Vg.=250V

@ EL34 357.7ISSUE 2

OUTPUT PENTODE-



ANODE CURRENT PLOTTED AGAINST ANODE VOLTAGE WITHCONTROL GRID VOLTAGE AS PARAMETER Vg2=360V

cW ~EL34 357-8ISSUE 2

OUTPUT PENTODE



OUTPUT PENTODE



~'(.;.w.J(000000 00000 O Oj)~O~OO--m

;!i, .+~..I l' .I

02

-:1 ~ ~ ,

-ti:J',

II

~>--+~ ~

::r;.~ , .,

~Ei05::=.

0~ ~

!(VUI)1

(..IU,)(I6-I!).!~ ~ oo

0.

N~

PERFORMANCE OF TWO EL34 IN PUSH-PULL WITH DISTRIBUTED LOADCONDITIONS. SCREEN-GRID TAPPING AT 43% OF PRIMARY TURNS

@ISSUE 2 EL34 105610

~--o

.-!~:,1.:;.:.

]~

»c:~$~~.~'!' c

..

.&

OUTPUT PENTODE

Output pentode roted for 25W onode dissipotion,


.~

0Q

c> E

°

OM

::;.

~:

~+

(vw)I ~

l""'A)U!A ~

~Ofo) ...0 ~

0.

2~

PERFORMANCE OF TWO EL34 IN PUSH-PULL WITH FIXED BIAS ANDVb=375V

eISSUE 2 EL.34 1056-1 f

OUTPUT PENTODE



;;

12

.,"'; " , "(Vw)1 9 9 8 o-~- "' -

O

-0

0. ~, ( .."A ) U!A

~(010) .O.a ~

PERFORMANCE OF TWO EL34 IN PUSH-PULL WITH FIXED BIAS ANDVb=425V

ISSUE 2 EL34 1056-12

OUTPUT PENTODE



PERFORMANCE OF TWO EL34 IN PUSH-PULL WITH SEPARATE ANODEAND SCREEN-GRID VOLTAGE SUPPLIES AND FIXED BIAS V"(b)=SOOV,

Vg2(b)=400V

@EL34 256-13ISSUE 2

OUTPUT PENTODE

Output pentoderated for 25W anode dissipation,


PERFORMANCE OF TWO EL34 IN PUSH-PULL WITH SEPARATE ANODEAND SCREEN-GRID VOLTAGE SUPPLIES AND FIXED BIAS Va(bl=800V.

V"(b)=400V

1@EL3. 256.11ISSUE 2

OUTPUT PENTODE



PERFORMANCE OF TWO EL34 IN PUSH-PULL WITH CATHODE BIASAND Vb=37SV

~EL34 1056-15ISSUE 2

ISSUE 2

EL34OUTPUT PENTODE

EL34 1056-16

OUTPUT PENTODE



PERFORMANCE OF TWO EL34 IN PI,JSH-PULL TRIODE CONNECTED

ISSUE 2 EL34 1056-17

Documents

Valve & Amplifier Design, EL34 (6CA7) Data, Mullard Valves