5
4
3
2
1
D
D
Original ZX Spectrum +128/+2 composite video output
Suitable for use also on any +2A/+3
Composite video output (better solution)
Suitable for use on any +128/+2/+2A/+3
Link "P" connected = Peritel option
Link "S" connected = Standard option
Component part number is not related to
real Spectrums
+12
The rest of RGB connector connections not shown here
R100
22
C
C
D3
+
to TR2 (part of RF modulator circuit)
C100
22/25V
1N4148
1N4148
1N4148
TR4
R101
"P"
SK2
pin6 / TEA2000
R10
2.2K
2N3904 RN1
LK2
"S"
LK4
6
pin6 / TEA2000
5
6dB
3
INT_VID
J100
Video Out (BNC connector)
R102
6
SW_OUT
C101
1
0dB
75
7
100
1
3
4
5
10/16V
0dB
INT_BUF_OUT
2
U100
TEA2014A
1
2
75
RGB connector
EXT_VID
GND
D7
+
D8
8
D4
8
2
R9
1K
SWITCH
+12 analog
Vcc
+12 analog
7
1N4148
B
B
Note1: on +2A/+3, pin1 of the RGB connector has
a resitor connected to +12V (R44, 1K); if you
wish to use this pin for composite video output,
you MUST remove R44
Note2: the monitor or TV input connector (BNC,
RCA, SCART, whatever) MUST have resistive 75
ohm impedance termination, else this drawing
will not work !
Resisteve impedance is the usual situation on most
todays TV sets, however, you should check this in
case something does not work as expected
A
A
Unless otherwise noted:
all resistors are in ohms
all capacitors are in microfarads
(concept & drawing by Cristian Secara)
Title
ZX Spectrum +3S (partial schematic - video output)
Size
A3
Date:
5
4
3
2
Document Number
Monday, October 23, 2000
Rev
1
Sheet
1
20
of
20