Quick update on the 3047A software:

(1) Implemented the beat note search for low frequencies – using the 3562A analyzer. This is now working just great, using a zero crossings algorithm.

(2) Implemented the loop correction (including the “Difcorrection” method).

(3) Implemented the phase detector slope measurement for low frequencies – using the 3562A analyzer.

(4) Implemented loop characterization for below 20 Hz. This utilizes the noise source of the 3562A, and both channels, to measure the transfer function. Actually, sounds easy, but took quite some effort to get it to work properly.

That’s the latest version of the source.
main – 150329 backup

A quick test with the 8782B – and, it seems to work!

Will put it to a test with a very narrowband PLL soon.