Page 1
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)
Trademark(l} ® Registered
Morco{_}
shown
gain
the
the
lI:egi.frodo{sJ
in
the
and
and
left
to
29
noise
3-
a
63
Page 2
~===
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
/
oJ
..
v
~'
«\r;,..:J~/
~
/
~
.'>
V
~
30
1/
/
/
~
.
~
~
I
/
.-
~
1.0
db
/
/
/ /
1/
. /
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 -
Page 3
•
====~
and
is
lower
useful
shown
achieved
transconductance
in
the
Although
in
Fig.l
at
much
input
the
8056
represent
lower
stages
is
plate
(gain).
of
not
specifically
typical
voltage
As a result,
mobile
noise
communications
performance.
and
dissipation
the
controlled
8056
is
receivers.
for
noise,
with
somewhat
particularly
the
data
•
•
•
Description of Measuring
The
test
1n
this
INPUT
UG-58/U
Cl:
2200
soldered
connector
:
C
Hammarlund APC·50
2
C
22
pf,
:
3
:
C
E.
4
CS:
C6:
C
7
CS:
C
g
F.
E.
F.
E.
F.
2200
:
soldered
Hammarlund APC-25
:
2200
soldered
connector
circuit
Note
---1h--,.-~~""""""--+
C,
pf,
is
Eo
uncoated
directly
tubular
used
shown
disc
on
ceramic
Johnson 5 Mll
Johnson
9 MBll
Johnson 9 Mll
pf
J
pf,
uncoated
directly
uncoated
directly
disc
on
disc
on
Circuit
for
Fig.3.
in
ceramic,
input
ceramic,
chassis
ceramic,
output
the
gaIn
L3
...f~ll'-.,----~J1j~i'--,-,,--;--lL......-
I I -
The
and
circuit
TYPE
8056
noise
LS
measurements
consists
described
of a partially
OUTPUT
UG-290/U
C9
Ca
L4, L7: Ohmite
1
loop
9
cm
long,
2
cm
wide,
chassis
L3: B
&W
turns
5
cm
Miniductor
of
slightly
chassis
silvered
2.5
cm
1
cm
wide
of
No.14 magnet
bent
1
No.14
bent,
strap
long,
Eb
rf
to
to
2.5
3002.
magnet
1.8
0.4
bent
choke,
form
cm
5-1/2
wire,
cm
from
cm
wide,
to
form
Z-235
wire
a U
from
a U
•
Chassis
deep,
parti
wall.
and
coil
...
the
neutralized
approximately
50-ohm
source
load
admittance
Noise-Figure
adjust
the
circuit
5·1/2
of
tioned
The
is
sliced
L3 and
partition
O.024-inch
to
parti
capacitor
and
inches
the
tion
1/16
partially
grounded-cathode
4
megacycles.
through a pi
for
Meter
for
network; a similar
minimum
and Model 343-A
minimum
long,
copper
full
depth
cuts
acrOss
inch
Fig.3-Test
C4
into
are
amplifier
The
output
noise
noise
4
inches
tinned
2-1/2
the
mounted
shielded
circuit.
figure.
VHF
and
·3·
inches
the
socket.
from
stage
of
the
network
A
Noise
also
wide,
on
center
on
the
from
the
the
input
which
1-1/2
wiring
the
of
the
Neutralizing
grid
has a bandwidth
amplifier
is
used
Hewlett-Packard
Source
for
(diode)
noise
inches
side,
input
socket
side
of
circuit
is
.
matched
to
adjust
Model 342-A
are
used
measurement.
to
of
a
the
to
An
Page 4
1
additional
test
chassis
noise
figure
calculation.
The
test
between
grid
affected
complete
mately
low
on
SO
plate
noise
amplifier
and
the
of
this
amplifier
and
plate;
except
by
losses
neutralization,
db
at
normal
current.
figure
and
gain
having a noise
input
of
the
amplifier
is
neutralized
as a result,
in
the
the
ratio
plate
However,
current,
the
appears
figure
noise-figure
is
excluded
only
the
inductor
of
forward
and
effect
to
of
be
negligible.
of
6.3
meter;
from
by
use
feedback
itself.
to
reverse
decreases
the
incomplete
db
is
used
the
the
test
of a shunt
conductance
Because
gain
to
about
neutralization
between
effect
results
inductance
of
is
of
is
not
the
approxi-
40 db
the
the
by
in-
at
Information
liable.
However,
nor
for
parties
implication
any
which
furnished
no
responsibility
infringements
may
or
result
otherwise
by
under
ReA
of
from
is
patents
its
any
- 4 -
believed
is
assumed
use.
patent
or
No
to
or
be
by
other
license
patent
accurate
ReA
rights
is
rights
and
for
its
of
granted
of
ReA.
re-
use;
third
by
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