PA ZTE DP11 Made in China for COFDM on 460MHz with two transistors MRF 9210 -> conversion to 432MHz by OK1VPZ

Power has increased from 40W to 250W with 55% efficiency.

                                     Power supply could be increased to 27V DC. Input abt. 2.5 - 3W

                                     Lambda/4 cables could be replaced by teflon coax 25 Ohm

                                     The key part of 70cm PA conversion is the inductance L between transistor collectors - we used Cu strip 4.5mm wide, 16.5mm long and ca 4.5mm above the PCB. Both ends of the                                      strip inductance are bent down to the PCB

                                     Completed June 2018

                                     pic: original transmitter PA unit

                                     datasheet MRF9210  https://www.ok2kkw.com/info/mrf9210.pdf