FWD Power meter scaling
With this adjustment you can fine tune JUMA-TRX2 output power display to
show actual RF power output. Connect accurate wattmeter and dummy load
to your JUMA-TRX2. Select first TUNE mode and then PWR meter display.
Push PTT and read JUMA-TRX2 display and the external Wattmeter.
Example:
External meter reads 9W and JUMA meter 8W and calibration value is 23.
Divide 9/8 = 1,125 and correct calibration value with this. New calibration
value 23 * 1,125 = 25,875. Go back in the Service Mode and dial in new
calibration value 26. Save this and recheck the readings.
Drain current (ID) meter scaling
This adjustment is not necessary but if you like to check and calibrate your
JUMA-TRX2 PA ID current display do following:
First select TUNE mode and then ID current display. Push PTT, read JUMA-
TRX2 ID current display and measure voltage across R17 or R21 in the PA
board. Calculate drain current from the voltage = U / R. If you measured
0,209v divide it with R17andR21 value. 0,209V / 0,11R = 1,9A. If necessary
correct ID scaling Cal mult value. Procedure is same as in power meter
scaling.
See also PA board tuning instructions. Particularly bias current adjustments.
Return to the ”factory default” values
In case you want to return to the ”factory default” values select on the LCD
display:
Push FAST long =
Factory defaults
And press FAST button about five seconds.
