Eddystone 990R - Appendix D; IF Converter Type 959

APPENDIX "D"
IP
CONVERTER
TYPE
959
The
IP
Converter
Type
959
is an
ancillary unit
for use with
the
990R
VHP
Receiver
when
IP
output
is
required
at
5*2
MHz
to drive
the
associated
Panoramic
Display
Unit
Type
EP17R.
A variant of the
standard
959
Unit
is available
for
rack-mounting
(959
/l
)
.
The
unit employs
two
transistors
(Mullard
0C171)
as
Mixer
(TRl)
and
Oscillator
(
TR2
) o
The
oscillator
is
crystal-controlled
at
15*9
MHz and the
unit
operates
as
a
n
no-los
s/no-gain"
device with
a
bandwidth
of 1
MHz.
BNC
coaxial sockets
are
fitted
for
input
(10.7
MHz)
and output
(
5.2
MHz)
connections-
A
flying lead
terminates
in
a
polarised
connector to mate
with the
12V DC
socket
at
the
rear
of
the
990R
Receiver-
The
connector
carries the
+ve
supply
lead
only
and
has
a
shorting
strap
to
complete the receiver supply
as:
on the
normal
shorting
plug
fitted
for
AC
working-
The
-ve
return
is
via
the
coaxial
leads
to avoid
shorting
out
the
switch S10A and
the
fuse PS1
in
the
main receiver.
This would
occur
if
the
-ve
line
was taken via
the
12V
DC connector.
A circuit, diagram
of
the converter
is
given
on the
following
page. Other
converters
can
be produced
to
special
order for applications
where IP
drive
is
required
at
other
specified
frequencies.
Component Values
for
IP
Converter Type
959
»
Ref
Value
Type
Tolerance
Rating
Cl
lOuF
Tubular Electrolytic
+50
f>/o
-10^0
16V
C2
O.OOlliP
Tubular
Ceramic
2CF/o
750V
C3 O.OOljiF
Tubular
Ceramic
20
°/o
750V
C4
20pP
Tubular
Ceramic
i<y/o
750V
C5
-
Reference not
allocated
-
C6
-
Reference not
allocated
-
—
C7
O.IijlP
Polyester
2<J?o
250V
C8
O.OOlpF
Tubular
Ceramic
20
fo 750V
09
lOOpF
Polystyrene
J?°
125V
CIO
lOOpP Polystyrene
5/i
125V
Cll
200pF Polystyrene
5%
125V
C12
lOOpP
Tubular
Ceramic
IQfo
750V
R1
1000
Carbon
10°/o
R2
-
Reference not allocated
-
R3
2,2000
Carbon
10
io
Jr-
watt
R4
15,0000
Carbon
left
2-
watt
R5
1,0000
Carbon
W/a
gr-watt
R
6
-
Reference not
allocated
-
—
R7
8,2000
Carbon
IQffo i-watt
R8
82,0000
Carbon
IQP/o
g--watt
R9
1,5000
Carbon
IQjo
-g-watt
RIO
5,6000
Carbon
5f°
§*-wat
t
Rll
5,6000
Carbon
5%
-g--watt
l-
-
43
-