Amplifier is based on a Motorola app note. Looking for 100MHz 50W average or so. Amp's sink must be forced air cooled.
I used 6 1206s for the divider. You can see them in the first picture. They would dissipate around 1/2W with a shorted output. Should handle 3/4W. This is the limit.
Spent a little more time trying to flatten it out. Around 0.3dB now. Last picture is 10dB/div. 0dB center, 10dB offset. Red is basically at -40dB in far left. Cursor is at 300MHz where it gets pretty bad.
Using a small fan with 50VDC applied and half the sink, temp gets to about 80C. With the sink together, around 50C.