Campbell Scientific RF320-Series Ritron VHF/UHF Radios - Manual (Page 26)

RF320-Series Ritron VHF/UHF Radios
For a number of the following procedures, it will be necessary to manually key
the radio’s transmitter. Campbell Scientific’s push-to-talk switch accessory
(CSI# 13588) is used for this purpose. Connect the push-to-talk switch to the
middle 10-pin connector of the radio-to-modem interface cable.
Ensure that the radio is properly connected to an antenna or a
suitable dummy load before activating the radio’s transmitter.
Operating the transmitter for extended periods of time without an
antenna or dummy load connected could degrade the service life
of the radio. NOTE
8.3.1 Input Voltage Checks
8.3.1.1 Input Voltage Range
Disconnect the DB-15M connector of the radio-to-modem interface cable from
the radio and, using a DMM configured to measure DC Volts, verify that an
input voltage of between 9 to 17 Vdc can be measured between Pin-6 (+) and
Pin-15 (-) of the DB-15M connector.
Since the contacts of this connector are male pins, this
measurement may be more easily accomplished using a gender-
changing adapter or a mating connector temporarily connected to
the DB-15M connector. NOTE
8.3.1.2 Input Voltage Load Regulation
Verify that the radio is installed and connected in accordance with the
interconnect diagram (FIGURE 6-1). Configure the DMM to measure DC
Volts and connect it between the red and black leads of the radio-to-modem
interface cable at the point where the leads connect to the radio’s power source.
Depress the push-to-talk switch and verify that the measured voltage does not
drop below 9 Vdc with the transmitter activated.
8.3.2 Radio Current Drain
Disconnect the DB-15M connector of the radio-to-modem interface cable from
the radio. Disconnect the red lead of the radio-to-modem interface cable from
the point where it connects to the radio’s power source. Configure the DMM to
measure DC current and connect the positive probe of the DMM to the power
source and the negative probe of the DMM to the red lead of the radio-to-
modem interface cable. Reconnect the DB-15M connector of the radio-to-
modem interface cable to the radio. The receive/standby current drain displayed
by the DMM should be within the range of 20 to 30 mA with an input voltage
range between 12 to 14 Vdc. Depress the push-to-talk switch to measure the
transmit current drain. The transmit current drain should be within the range of
900 to 1200 mA with an input voltage range between 12 to 14 Vdc.
8.3.3 RF Output Power Check (Dummy Load)
Verify that the radio is installed and connected in accordance with the
interconnect diagram (FIGURE 6-1). Disconnect the antenna cable from the
radio’s antenna connector. In accordance with the manufacturer’s instructions,
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