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Technical Manual
MX800 Transceiver T19 Option
1.5.1.2
Status Tone Encoder & Decoder -TX Alignments
1.
PTT the transmitter.
2.
Using a signal generator, apply a 1 kHz Tone with the line up level as required
(default -10dBm), injected into the rear RJ45 connector, pin3 & 4. (Balanced audio)
3.
Disable AGC on Option Board JMP13 (Position 2-3)
4.
Adjust TX input line gain RV5 to obtain 1 Vp-p at IC13 pin 1.
5.
Monitor TX modulation depth and insure it is equal to the nominal deviation level. If
not adjust RV4 on the motherboard to obtain correct level.
6.
Enable AGC by linking in Jmp13 in position [1-2]
7.
Using a signal generator, apply a Key tone to Audio level @-10dB.
[–10dBm0] (Default –20dBM)
8.
Adjust RV7 so that the combined audio and key tone signal are set to the required
onset compression level.
1Vp-p at IC13 pin 1. (JMP9 2-3)
(Default compression level are, audio -20dBm and key tone signal is set to -30dBm)
9.
Monitor TX modulation depth and insure it is equal to the nominal deviation level. If
not adjust RV4 on the motherboard to obtain correct level.
1.5.1.3
Status Tone Encoder & Decoder- RX Alignments
1.
Using a 600ohm termination monitor RX line output level. This output is located on
the rear of the MX800, RJ45 Line I/O connector pin 1 & 2 (balanced audio)
2.
Set the receiver modulation frequency to 1 kHz and the FM deviation to nominal for
the particular RF receive frequency of the test channel. At a RF level of –60 dBm.
3.
Remove JMP20 and adjust Line Output level RV4 to obtain nominal line output
level (-10dBm is the default level).
4.
Fit JMP20 in positions [1-2] and remove JMP7.
5.
Toggle RF signal ‘on’ and ‘off’ to ensure key tone represent mute status.
6.
With the key tone present, adjust RV1 so that the ratio of Key tone to Audio level is
@-10dB. (–10dBm0)
7.
Fit JMP7 in positions [2-3]
Two wire Mode only
8.
Using an oscilloscope, monitor the audio on IC4 pin1 also insure that Pin1&2 of
SK5 Terminated to a 600ohms load.
9.
Adjust RV2 for minimal Audio level on IC4 pin1. (Aprox <5mV)
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© SPECTRA ENGINEERING 2010 Revision 1.0.4