The input cable of your 'scope has a capacitance to ground that cuts high frequencies when the output impedance of the circuit is higher than with the low output impedance buffer.
Ya, but, it a 300ohm... ya, but nothing! 15pf at 10 MHz is 1,061?s.
2.95 volts into a 330?--1061? voltage divider is 2.3 volts out.
I didn't post it here, but I have 2.95 volts output at 1MHz and 2.3 volts
output a 10MHz. That's a pretty close correlation!
Hmm, maybe my other amp was OK.
Well how the heck am I going to be able to measure this thing.
I guess I just need to stick the Diode Detector on it and see
how linear my output is with frequency.
The parts on your pcb are too far apart that adds stray capacitance.
Stray capacitance around the parts also cut high frequencies.
I could probably tighten it up some, but if I'm going to do that, I might as well go to SMD.
Back to the bench.
Thanks very much for the advice, I was aware of this, but I'm so used to working at 1MHz, that
I didn't even consider that could be the problem!
Thanks, Mikek