User's Manual

120 20170-200 Paragon
PD
Technical Manual36
6.2.3.4 Low Frequency Balance Adjustment
1. Apply the following settings to the IFR:
– Receiver mode and Oscilloscope display (Source: Demod Out Connector).
– IFR RX frequency to match the radio transmit frequency
– IF Filter set to 30KHz
– Zoom the Deviation window: select 10kHz Range and DC coupling.
2. Select the active or, the lowest (in the case of multi-channel base) frequency channel (via dip
switch)
3. Transmit a square wave by pressing the BDLC
PD
’s PF1 button and following the procedure out-
lined in section 3.2.1.1.2.2 or run on another computer the RIS program and press the Flatness test
button. Adjust RV-105 (REF MOD) close to the microphone connector, for best wave shape; no
damping, no overshoot. Record the deviation read.
4. If transmission has not ended by itself, press PF1 or RIS’ Flatness test button again to stop it. For
single-channel unit, proceed to step 7.
5. For multi-channel unit, select the highest frequency channel. Transmit a square wave by pressing
the BDLC
PD
’s PF1 button and following the procedure outlined in section 3.2.1.1.2.2 or run on
another computer the RIS program and press the Flatness test button. Record deviation again.
6. The difference in deviation between the two channels should be less than ±300 Hz. If not, re-
adjust RV105 to "average" the square wave shape on both channels until the spec is met.
7. To confirm the adjustment, select the active, or the lowest frequency channel. Compare the devia-
tion produced between:
- TX ON (Modulated) and
- Random data tests,
The difference should be lower than 300 Hz. For multi-channel unit, repeat this step on the highest
frequency channel.
8. Select the active channel. Transmit a TX ON (Modulated) adjustment tone by pressing the
BDLC
PD
’s PF1 button and following the procedure outlined in section 3.2.1.1.2.2 or run on an-
other computer the RIS program and press the TX ON (Modulated) button. Make sure that devia-
tion level read on the IFR correspond to model and bit rate in use (see Table 8 - Typical Carrier
Modulation). Re-adjust deviation as necessary referring to Checklist B - page 26.
6.2.3.5 Exciter Power Output
1. Apply the following settings to the IFR:
-
Receiver mode, Output T/R
-
IFR RX frequency to match the main radio TX frequency
-
IF Filter set to 30KHz
-
Select auto range in the Power reading window
-
Connect the coaxial cable from the IFR T/R to the Exciter output connector
2. Key the Exciter by pressing the module PTT button. The output power must be:
- 800 MHz (T881) = 5W ±300mW.
3. If 5Watts is not reached, adjust helical #L300 for maximum power output (which should be at
least 7W); adjust RV356 down to 5W.