RCA 8056 schematic

AN-195

•

•

•

Noise and Gain

Nuvistor Triode at

This
RCA-8056
200

voltage.

given
possible
conditions

Design Features of

The
featuring
at

plate-supply
elements
element

the

base

Sections

lugs

for

the

socket

Note

low-voltage

megacycles

When

in

the
to

estimate

at

8056

small

of

the

is

supported

wafer.

of

the

for

socket

tube

so

that

provides

over

used

technical

any

is

a low-mu

size

tube

One
shell
insertion.

leads

the

nuvistor

a

in

the

operating

the

8056

and

voltages

are

by a

lead

extending

and

can

use

of a tube

of

200

information

triode

range

conjunction

data

high-transconductance

tripod

of

for

performance

point

light

of

12

mounted

of

each

These

be

used

on

the

under

practical

with

these

with

weight,

to

coaxially

arrangement

set

beyond

shield

types,

of

reasonable

especially

30

volts.

is

the

indexing

to

ground

is

the RCA-8056

Megacycles

noIse

noise-matched

values

values

these

on

of

used

base
lugs

unnecessary.

figure

of

this

tubes

triode

developed

The
ceramic
leads
as

the
wafer
also

the

metal

and

of

plate

other

information

accuracy.

characteristics

under

of

nuvistor

cylindrical

base

which

external

serve

provide

shell

gain

conditions

current

small-signal

for

operation

wafers.

extend

connector.

as

protection

through

of

the

and

makes

design,

active

Each

through

indexing

the

at

it

•

Noise Figure

Curves
Figs. 1 and
of

operating

curves

simultaneously

plate
of
reduce

of

16.4-db
volts

©

1963
All R'Qhll Reserved
Printed

show

For

example,

current

approximately

the

noise

the

4.5-db
gain

and

the

by

Radio

Corporation

in

U.S.A.

and

Gain

of

constant

2,

respectively.

point

how

the

in a desired

of

ll-milliamperes

fIgure,

noise-figure

curve

plate

of Americo

nOIse

to

be

operating

a

tube

16.4

db.

in

Fig.2.

current

RADIO CORPORATION OF AMERICA, HARRISON, NEW

figure

These

determined

point

direction.

operated

If

it

the

operating

curve

If

is

elECTRON

and

curves

at a glance.

can

be

at a plate

has a noise

is

desired

point

in

Fig.l,

the

plate

increased

TUBE

DIVISION

gain

varied

permit

voltage

figure

should

and

voltage

to

13

for

the

8056

the

effect

In

to

change

of~volts

of

to

increase

be

above

milliamperes,

JERSEY

the

is

are

of a change

particular,

two

parameters

4.5

db

and a gain

the

moved

decreased

to

(interpolated)

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Morco{_}

shown

gain

the

the

lI:egi.frodo{sJ

in

the

and

and

left

to

29

noise

3-

a

63

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figure
than

17

i~

6

14

"

8

6

4

,

o

reduced

db.

Ef "6.3

to

4 db and

the

gaIn

IS

increased

to

slightly

more

•

V

//1

d'

~

tl /

VI

10

/

-

/

L/'~

~

'0

PLATE VOLTS

/

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v

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/

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V

~

30

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/

/

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.

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I

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.-

~

1.0

db

/

/

/ /

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V

::::;;

4

.-/

1.5

db

/

-::::::::

/

./

•

50o

The optimum

1

imi

ts

volts

8056.

and a plate
therefore,

16

14

12

4

2

o

is

Er"&.3

about

v

Fig.l -Noise

10

Fig.2 -Power

noise

3.7

figure

db;

current

is

somewhat

this

within

value

of

15

better

figure

'0

PLATE VOLTS

..

gain

at

the

rated

is

obtained

milliamperes.

than

at

GAlN;17db

noise

noise

that

match.

lbdb

15d'O

140'0

13db

l2db

GAIN",n

db

10db

"b

8.b

30

plate-current

l

match

with a plate

The

of

the

40

.

noise

7586.

and

dissipation

vol

tage

figure

or

the

50

of

of

7895,

•

•

24

the

•

- 2 -