I was artificially limiting my PLL range by directly driving the Marconi with the IF output of the mixer - this restricted it to ~500mV range.
The input range of the Marconi is (measured to be) +/- 2V (~ 8x higher than the mixer output I was using. Free-ish lunch here.
We might have to wait until we're cold to have low enough drift to use the Marconi in any truly low noise way, but I believe it's no longer limiting at even room temperatures. Beat noise spectra tomorrow. |