On Sat, Mar 5, 2022 at 02:32 PM, Jinxie wrote:
@Ozan
That is a very valid observation if indeed the wave is digitised further down the line. However, whilst that would certainly work fine as-is for digital purposes, is it realistic to suppose that a company like HP, with all its attention to detail, would allow a VCXO into production that produced a dirty signal like this? Is it not more likely that this distortion might be indicative of some underlying issue elsewhere which could be fundamentally related to the YTO unlock error?
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Hi Jinxie,
Could you put screenshot of the waveform in a photo folder, or attach to the posts if the image is not large? Also note how you are measuring (50-ohm terminated, with a scope probe etc). What may look like a bad signal to you could be OK for its purpose. Perhaps one of the group members can compare with their 8566B. I do have RF section of an 8566B bought for parts but I don't know if my reference generator works.?
At a high level: A7A1 has its own lock signal which can tell you if there is an issue in that area. Are you sure reference section has an issue? Do you have 100MHz counter to measure the 100MHz output?
As Bruce said there are lock indicators on M/N block. I attached the picture on mine that shows green LED for lock. I believe different PLLs lock at different spans but as I wrote above I don't have a way to exercise them (yet).?
Ozan
