The MFJ-1708SDR T/R switch uses a relay, which switches from transmit to
receive mode. When no power is applied to the unit, it is in the transmit mode.
Once power is applied the relay switches on and the unit is in receive mode.
When the unit senses RF or the control line is grounded from a keyer or PTT
switch, it switches the relay off and the unit is in transmit mode.
The delay adjustment allows you to change how fast the relay switches back to
the receive mode. It is adjustable from 0 to 2 seconds.
The MFJ-1708SDR T/R Switch requires 12 VDC or 110 VAC with MFJ-1312D
Power: 2.1mm Coaxial power input jack with center pin positive and
PTT: RCA input jack
Delay: Controls time delay for switching
Radio: SO-239 Coaxial connector
Antenna: SO-239 Coaxial connector
SDR: SO-239 Coaxial connector
Remote Antenna Switch Ports: Two, SO-239
Remote Antenna Switch RF Input: Single, SO-239
Remote Antenna Switch Power Handling: 100 W key-down
Remote Antenna Switch Control Connector: External
Remote Antenna Switch Frequency Coverage: 1.8-30 MHz
Relay Unit Control Cable Connection: External
200 W PEP/100 W CW.
These switches are not weatherproof and are not for outdoor use without a user-supplied weather enclosure.