12. Representative Test Data
Signal Input to:
Frequency
Input
Output
Remarks
(a) Junction of
1,000 c/s
0
.
8V
50mW in 3 ohms
AUDIO GAIN MAX.
A.F. LEVEL MAX.
C218 and C221B 1,000 c/s
1
.
0V
10mW in 600 ohms R.F. & I.F. GAIN
(output to line)
MIN. B.F.O. off.
LIMITER off.
(b) Grid V16
100 kc/s c.w
360mV
100
µ
A R.F.
B.F.O. off
level
Grid V14
100 kc/s c.w
850
µ
V
100
µ
A R.F.
SYSTEM switch
level
MAN. R.F./I.F.
GAIN MAX.
Socket SKT303
100 kc/s c.w
800
µ
V
level
100
µ
A R.F.
1Mc/s
and
1
.
7Mc/s
crystals removed. V.F.O.
switch
set
to
EXT.
Mc/s
scale
set
to
20.
BANDWIDTH 3kc/s.
(c) Grid of
2.2 Mc/s c.w
25
µ
V
100
µ
A R.F.
1 Mc/s and 1
.
7Mc/s
second mixer
level
crystals
(TP3)
2.5 Mc/s c.w
25
µ
V
100
µ
A R.F.
re-inserted.
level
V.F.O. switch set
2.9 Mc/s c.w
25
µ
V
level
100
µ
A R.F.
to INT. Image response
(i.e.
receiver
frequency
plus 200 kc/s) should be
at least 60db down.
(d) Aerial input
3.5 Mc/s c.w
250mV
0.5 at TP2
WIDEBAND 75-ohms
(WIDEBAND
INPUT R.F.
75-ohms)
ATTENUATOR MIN. V5
and V7 removed. Valve
voltmeter input shunted to
12pF.
(e) Aerial input
3.5 Mc/s c.w
250mV
0.5 at TP3
WIDEBAND INPUT
(WIDEBAND
R.F. ATTENUATOR
75-ohms)
MIN. V5 and V7 refitted.
V9 and 1 Mc/s crystal
removed. Valve voltmeter
input shunted to 12pF.
MEGACYCLES scale 3.
(f) Grid V10
37
.
5 Mc/s c.w 100
µ
V
1V at TP3
V9 and V5 and 1Mc/s
Grid V8
70
µ
V
crystal removed
TP1
8mV
Valve volt- meter input
shunted to 12pF.
(g) With the 1 Mc/s crystal in place, the output at socket SKT2 should be approximately
[30]
Summary of Contents for RA-117
Page 1: ...Racal RA 117 Radio Receiver...
Page 24: ...Detailed Circuit Description 24 at maximum is the correct calibration maintained...
Page 32: ...32...
Page 70: ...Illustrations 70...
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Page 72: ...Illustrations 72...
Page 73: ...Illustrations 73...
Page 74: ...Illustrations 74...
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