Specifications
167
Potentiometers
with the receive and transmit FFSK signals. To activate the test tones, enter the Software
Configuration Program and select FFSK Level Set in the Main Menu.
Table 12 summarizes the purpose of the pots on the transponder main board. After the
table, each pot is individually described in more detail.
The potentiometers are presented in the order of adjustment for a new installation.
Table 12: Transponder Board Potentiometers
FFSK OUT (R108)
This pot adjusts the output level of FFSK transmissions. The Model 6203 does not
normally use this control.
The Model 6203 FFSK output level for a radio communications interface should be set to
the radio manufacturer’s specification. It is normally recommended that the data signal
produce a 2.5 kHz deviation on FM or PM type transmitters. If you do not know what the
radio input level should be, stick with 1 Vpp (0.3 Vrms) unless the received signal is too
small at the other end. In that case, JP-5 may need to be moved to PWR. If the received
signal is radio born and distorted, use the RAD position for radio inputs which need to be
smaller than the level available with the TEL position.
Pot # Name Description
R108 FFSK Out This pot adjusts the output level of FFSK transmissions.
R62 FFSK In This pot is the secondary receive level adjustment for the
FFSK input.
R135 2-Wire RCV This pot is not used for FSA systems. In should be turned
fully counter-clockwise.
R107 4-Wire RCV This pot, along with R135, adjusts the receive signal level.
To start out it should be turned fully clockwise
R84 COR This pot adjusts the COR detect circuit.
R86 VOX This pot adjusts the VOX detect circuit and needs to be
adjusted regardless of the communication mode being used.
R63 MIC This pot adjusts the handset mic input signal level.
R61 TONE This pot adjusts the signal level of tones generated by the
Model 620x.
R137 AUX RX This pot controls the input level of audio coming from the
AUX RX input. Set it in the center of its range.
R87 VOICE This pot adjusts received signal levels that are routed to the
PA system and handset ear.
R64 EAR This pot adjusts all signal levels routed to the handset
earpiece.