Broadband amplifier from 50 to 450 MHz

For my newly build 50-70 MHz amplifier I needed a suitable driver. I needed about 5W drive. I started with a CATV module, the BGY888. This module was able to produce 2.5W over a wide frequency range. At 2,5W it was going into 4dB of compression. It was enough for the initial tests. But I needed a bit more. The superb website of Paul W1GHZ offered a broadband design with a BLF2043. Found HERE

This was quickly build and was found to be working. Although the amplifier went in saturation very quickly, per advice of PA0WMX the output was changed to a 4C6 core with 37 Ohm coax ( 2 x 75 Ohm in parallel), this gave 7W on 50 & 70 MHz, 6W on 144 MHz and 5W on 432 MHz. Perfect for my needs. A 0dBm input driver for my 50-70 MHz PA!

Some tries to increase the inductance of the chokes gave no improvement.