Operation and Maintenance Manual

RF Technology T220 Page 7
2 TRANSMITTER INTERNAL JUMPER OPTIONS
2 Transmitter Internal Jumper Options
In the following subsections an asterisk (*) signifies the standard (Ex-Factory)
configuration of a jumper.
2.1 JP2: EPROM Type
Condition Position
27C256 2-3 *
27C64 1-2
2.2 JP3: Dc Loop PTT
This jumper enables or disables the keying of the PTT function by means of a dc
signal passed down the 600
Ω
line input pair. When enabled, JP9-JP11 control how
the dc signal is configured with respect to an internal optocoupler.
Condition Position
dc loop connected (enabled) 1-2 *
dc loop not connected (bypassed) 2-3
2.3 JP4: Audio Input Source
Either the 600
Ω
or the high-Z balanced inputs may be selected.
Condition Position
600
Ω
Input
2-3 *
High-impedance Input 1-2
2.4 JP6: Input Level Attenuation
This jumper permits coarse input sensitivity to be set.
Condition Position
0dB attenuation 1-2 *
20dB attenuation 2-3