A: 1 Vcc
A: 2 Gnd
B: 1 RFGnd
B: 2 RFin
59mm
3.1mm
A
1
B: 3 RFGnd
C: 1 TXE(MOD TX_ON)
C: 2 TXD (MOD NC)
C: 3 AFin (MOD NC)
C: 4 RSSI
C: 5 SQF(MOD NC)
C: 6 AFout
C: 7 RXD (MOD NC)
C: 8 + 4.4V out
C: 9 0V
8.9 mm
Squelch adj.
Input gain.
C: 10 PGM
1
C: 11 P1 (MOD TXD)
C: 12 P2 (MOD RXD)
C: 13 P3 (MOD NC)
C
Unit height
10mm
B
53.3mm
Figure 3: VX2M Footprint (Top) view
Pin Description - VX2M
Pins
A1
A2
Name
Vcc
GND
Function
4.5V-16V
Ground
B1
B2
B3
RF GND
RF
RF GND
RF ground
To the antenna
RF ground
C1
TXE (MOD TX_ON)
Transmitter Enable. Low = ON, Open = RX mode. Internal 10k pull-up to
4V
C2
C3
TXD (MOD NC)
AF in (MOD NC)
DC coupled digital data input for 3-12V CMOS logic. Leave open if unused
AC coupled Analogue Input Limit to 1Vpk-pk 10% to keep distortion <1.5%
and peak deviation >2.5kHz
C4
C5
C6
C7
C8
C9
RSSI
SQF (MOD NC)
AF out
RXD (MOD NC)
+4.4V out
0V
DC level between 0.5V and 2.5V. 60dB dynamic range
Noise operated carrier detect. Open collector. ON/low = no signal
600mVpk-pk audio. DC coupled, approx 1V bias. Muted by squelch
Open collector output of data slicer suitable for Biphase codes
Regulated DC supply. 75mA max. drain. Present if unit is powered
Ground
C10
C11
C12
C13
PGM
Serial programming/configuration input at RS232 level
P1 (MOD TXD)
P2 (MOD RXD)
P3 (MOD NC)
Parallel frequency select inputs. Inverted logic, internal 10k pullups to 4V
Notes:
1. Carrier detect on VX2M mutes the AF Out and RXD outputs. It can be factory disabled.
2. All the open collector outputs must be connected to Vcc/+4.4V out via a pull-up resistor.
3. The software incorporates a 1200baud dumb modem, compatible with that implemented in TX2M,
RX2M radios (I1200 tones and format)
4. With 1200baud modem mode enabled, parallel selection of channel is unavailable as the P1-P3 lines
are used for modem input/output operations.
5. PGM and MOD TXD (pin 10 and 11) tolerate true ±RS232 levels. No buffering is required.
Radiometrix Ltd
VX2M Data Sheet
page 3