We measured the TTFSS OLG, I didn't save the data but will attach several photos here. There is a feature that looks like it could be unstable at 1.68MHz, there are about 3 untiy gain crossings around 500 kHz. The FSS has a gain between the test points that mean that unity gain is at -10dB in this measurement.
67253 Craig mentions that the FSS OLG was 350kHz, we'd need to reduce the gain by 3dB to get back to a 350 kHz ugf.
Scans from the FSS after reducing gain.
In Marc's files above the A one should be magnitude for 100kHz to a few MHz frequency span, B should be phase for that measurement. C should be magntiude zoomed in on the 1.7MHz region, D should be phase for that measurement.