Spectra Engineering MX800 - TX Line Input Level and Nominal Deviation Alignment; TX Limiter Gain Adjustment; TX VF Gain Adjustment; Nominal Deviation Table

MX800 Transceiver Technical Manual
© SPECTRA ENGINEERING 2006 Revision 4.2.3
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JMP8 set to 1-2. This input is located on the rear of the MX800, on the Line
I/O connector pin 13 of the DB15F connector
Procedure:
1. PTT the transmitter.
2. Set the transmitter modulation frequency to 1kHz, 1Vp-p injected in
through the WB/ DCFM input, CN1 pin13 with JMP8 set to 1-2.
Note that signals injected into this port must be A/C coupled (1UF
cap) as this point is biased at 2.5VDC.
3. Adjust TX Limiter gain RV2 to obtain the nominal deviation. .
OR
(T98 Adjust TX Limiter gain RV2 until onset of clipping of waveform
peaks)
The potentiometers RV4 & RV1 sets the TX VF line input level and nominal
dev respectively. The transmitter modulating audio for this test is connected
to the TX VF input. This input is located on the rear of the MX800, on the
Line I/O connector pin 9 of the DB15F connector
Procedure:
1. PTT the transmitter.
2. Set the transmitter modulation frequency to 1kHz, at nominal line
input level (-10dBm is default level) injected in through the TX VF
input.
3. Adjust TX VF gain RV4 to onset of compression
OR
For T98 option adjustment.
Set the transmitter modulation frequency to 1kHz, at 4db above
nominal line input level (-6dBm for -10dBm default level) injected in
through the TX VF input. Adjust RV4 for the onset of compression.]
4. Set the transmitter modulation frequency to 1kHz, at nominal line
level (-10dBm) and adjust RV1 to obtain the nominal deviation.).
The third potentiometer RV3 sets the TTR Gain.
Procedure:
1. Remove TX PTT.