14-4-2018 updated Above the low noise preamp 50 - 4GHz ebay 6€ Tested 2 small porto antennas 1 Baofeng UV antenna left 2nd best signal on PI2NOS 2 eBay DIAMONDSRH805S wide band 144/432/1200 it works for its size as expected 3 piece of wire : best signal in the setup... Unit under test at workbench. It was stable 50mA at 5V few days, but sudden the current went up to 100mA And i could no longer adjust it with the negative bias Voltage. The - Voltage went to zero and the SPF input port became low Z. This SPF5189z was broken no oscillations, no input overload just it broke while i was receiving the PI2NOS 430.125 using a small antenna at the workbench. The specs of SPF5189z say it has an internal circuit regulating the bias current. Replaced . again with an other of the 5 spare SPF i have. The new one again could be adjusted at 50mA 5V The current raises to 150mA when removing the negative gate voltage. Where is that internal bias cir
Ham radio in JO33hg31 53.15N 6.35E