You raise the issue here of how to generate a signal with very low source resistance.
How about this idea.
Consider a signal source feeding a resistive divider consisting of Rs (source) and Rl (load).? This gives the relationship? Rs/Rl = Vs/Vl-1. So Rs approaches 0 as Vs and Vl become equal.
If you introduce an ALC control loop that monitors Vl and attempts to make Vs and Vl equal then the effective Rs becomes small.
A worthy idea or not ?
I played with this a bit recently and could quite easily get Rs down to one ohm at 50MHz.? Its part of an idea to modernize the old Boonton 250 RX meter.?
Bill
