Ramsey Electronics FX Series Manual page 15

1. PRIMARY CONNECTIONS:
PWR (near L20): +12-15 volts DC from S1.
GROUND: - DC from battery or power supply.
SPEAKER: both connections near U6 and U2.
MIKE: both connections (IN & GND) near notched end of U1.
SQUELCH: three connections near L1.
VOLUME: three connections near VR1 and C42.
ANTENNA: Center of SO-239 connected at "RF OUT" near C63.
CHANNEL SWITCH: Row of holes numbered 1 through 12. The switch
wiper (moving contact) is wired to +5V near "1."
EXT AUDIO: must be jumpered per options to enable pin 4 of J1.
2. TEST POINTS:
+12V, +8V, +5V, +8R, +8T permit checking for presence of those voltages.
+8R = Receive mode. +8T = Transmit.
TP1: For checking of VCO control voltage during alignment.
TP2: For checking VCO frequency with counter.
TP3: For checking U3 prescaler output with counter.
3. OPTIONS:
+12V, GND, +8V, +8T, +8R: provide supply voltage for accessories or
modifications designed by you. +8T and, +8R are near L9 and U4.
Jumper Options for Packet Operation: SPKR to EXT AUDIO: Speaker level
audio for packet (J1). DISC to EXT AUDIO: FM discriminator output for
packet.
COR: "Carrier Operated Relay" output from U1.
Binary Programming Holes: The row of holes alongside the Binary
Programming labels permits installation of ribbon cable for external
programming devices designed by the innovative amateur radio community.
switches or interfaces, or a row of internal DIP switches.