lected; when connected, the high output range is selected. Default: OFF. (low
output range)
J9: ( GPS input) This header provides for selecting AUX port pin 3 as either an
A/D input (position 1) or as GPS data input from an external GPS unit (position
2) . Default: Position 1.
J10: (input impedance) When placed on both posts (i.e., connected), this 2-pin
jumper sets the input impedance of the modem to 620 ohms. When the two posts
are not connected, input impedance is 10K ohms. Default: ON.
J11: (key output select) If an opto-coupled relay (RLY1) is installed and jumper
J4 is in the “Key” position (position 2), this jumper is used to select the relay out
-
put (RLY) or the FET open-drain output (OD) from Q2. When installed, this re
-
lay provides an opto-isolated “single pole single through” (SPST) switch for
keying external voltages of up to +/- 300 volts to ground. Maximum keying cur-
rent must be limited to 100 ma. Default: Open drain (OD)
J12: (EEPROM option) Not installed. This jumper would be used when the
EEPROM option is installed.
J13: (AGC disabled) Not installed. This jumper is metalised on the board to
give normal AGC operation. If the metal trace (top side of board) is cut, the AGC
circuit becomes simply a unity gain input buffer if R24 is 150K. The need to do
this would only occur in a special situation where a fixed input signal level was
available (about 1vpp) and AGC is not desired. Different signal gains could be
set with R24.
J14: (positive PTT option) Not installed. This jumper is metalized on the board
for normal (negative going) PTT operation. In some circumstances where posi
-
tive going PTT is required, this metalization would need to be cut. R40 and Q5
would then need to be installed.
J15: (test/hard reset jumper) When placed on both posts (after turning unit
power off), the processor will perform a “hard” reset once power is turned back
on. All command parameters will be set back to factory default values (parameter
settings and mailbox messages are lost). Default: OFF.
J16: (FSK/TXD select) When jumper J6 is in the FSK/TXD position, J16 is used
to configure the FSK data output signal to be either an FET open-drain (FSK)
signal or a true 0 to +5V digital signal (TXD) with 600 ohms drive impedance.
See J6. Default: FSK.
KAM’98 Jumpers Appendix B: Advanced Information
KAM’98 v 8.3 343 User’s Guide
To Next Page