User's Manual
120 20170-200 Paragon
PD
Technical Manual51
6.4.3.5 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:
-
VHF (T837) = 800 mW ±200mW
-
UHF (T857) = 1W ±300mW
6.4.4 Power Amplifier Module (T859 or T839)
-
Re-install the exciter module into the Paragon
PD
rack frame
-
Connect the Exciter module to the Power Amplifier.
-
Connect the Power Amplifier output to the IFR T/R connector or to a stand-alone BIRD
style power meter, terminated with a 150W dummy load.
-
Forward and reverse power alarm set (control) are identified on the PA cover.
6.4.4.1 Power Amplifier Power Output
-
Key the transmitter on the exciter and adjust the PA output for 100W using front panel
power control. If power cannot be reached, refer to section 6.4.4.4 for T859 UHF model
or to Tait T839 service manual for T839 model. Cable loss should be included in the
reading.
6.4.4.2 Forward Power Alarm Level
1.
Power up the PA and adjust front panel power control so that the output power is at the
alarm level required, usually 20% lower than nominal value (e.g. 40W if the PA normally
operates at 50W).
2.
Adjust the forward power alarm set (T859: RV48 or T839: RV101) so that the forward
power alarm LED lights.
3.
Adjust front panel power control (T859: RV63 or T839: RV109) for the normal operating
power level
6.4.4.3 Reverse Power Alarm Level (Optional)
1.
Power up the PA and adjust the front panel power control for the normal operating power
level.
2.
Place a known mismatch of the required value (e.g. 3:1 VSWR) and adjust the reverse
power alarm set (T859: RV52 or T839: RV105) so that the reverse power alarm LED
lights.
Example:
A VSWR of 3:1 can be simulated by connecting an unterminated 3dB pad to the
PA output. This will result in a return loss of 6dB.