User Manual

120 20191-001 Paragon-III Technical Manual

5.2.3.4 Low-Frequency Balance Adjustment

Note:

• PGM800Win version 3.00 or later must be used. Electronic potentiometer (256 step) is

used to allow channel adjustment of two-point modulation (Low freq. balance).

1. Apply the following settings to the IFR:

– Receiver mode and Oscilloscope display (Source Demod out connector, DC coupled).

– 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, refer to Figure 17)

3. Transmit a square wave by using CDip (using a second serial port).

4. Press EPOTs button. Adjust IC220 via PGM800Win “reference modulation” to obtain the best

square wave, no damping, no overshoot. (You can use either the mouse or up and down arrow

keys). Record the deviation read.

5. For single-channel unit, proceed to step 8.

6. For multi-channel unit, select the highest frequency channel. Transmit a square wave via CDip.

Record deviation again.

7. The difference in deviation between the two channels should be less than ±300Hz. If not, re-

adjust IC220 to "average" the square wave shape on both channels until the spec is met.

8. To confirm the adjustment, select the active, or the lowest frequency channel. Compare the devia-

tion produced between 1000 Hz sine wave test tone and Random data test pattern

The difference between the test tone and the test pattern should be less than 1.9 kHz for

xRC16FSK modulation set

For multi-channel unit, repeat this step on the highest frequency channel.

9. Select the active channel. Transmit a TX ON (Modulated) adjustment tone via CDip. Make sure

that deviation level read on the IFR correspond to bit rate in use (see Table 4 at step 6). Re-adjust

deviation as necessary.

5.2.3.5 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 at the coaxial cable end

connecting to the power amplifier should be:

- T881 = 5W +0/-300mW (RV502, Figure 21)