In this section I will describe the modification of the driver section of an ANDREWS UMTS unit to be used for 2320Mhz.
The smaller PCB contains following components:
Using the multippole connector the various connections can be found here: Connections
First test of this section of the board was on the DC levels and currents. Following settings were found to be more or less optimum for the time being:
Ir = 400mA ( U17 & FLL57) ( this value is heavily influencing total gain!!) Ir= 280mA ( MRF21045 )
After some modifications I have wind up with: 10mW input => more than 10Watts output Gain: 30dB
20 jan. 2012 Re-installed the aluminium cover to avoid oscillations and re-tested gain / power. 27 jan 2013 Removed the driver section from the original unit and installed on seperate ALU cooling block. Be sure you copy all the holes in the new cooling block, otherwise you will be faced to various shorts on the underside of the PCB. Re tested total driver section with supply voltage for MRF to 24volt. Results: 13dBm input => 20Watt ( 2320MHz) 15 mar 2019 Retested the driver and found both U17 and FLL17 died for unkown reason. Modifed the input to arrive directly at MRF21045
|