Ed Breya via Groups.Io <edbreya=yahoo.com@groups.io> 於 2018年6月11日 上午12:58 寫道：

I picked up this 500 MHz SA for cheap, because the CRT display is very dim, although it appears to work otherwise. I was hoping that some internal adjustments would fix it right up, but no. The unit is labelled Atten Instruments, model AT5005, and appears to be a Chines knockoff of the Hameg HM5005 - or maybe they're all made in China anyway. I couldn't find a manual for it, but did find the one for Hameg 5010, which includes schematics and more. It looks like the basic units are the same, especially the PS and CRT circuits, so I have what I need to check it out eventually. This is low priority, but it could be a handy toy SA for limited field use and such - it's definitely more portable than the good old real SAs I'm used to.

Just wondering if anyone happens to be familiar with this unit and common problems with it, to maybe find a quick fix. I haven't made any of the usual internal checks yet. One thing I noticed is that the focus adjustment needs to be at one extreme for a sharp, but barely visible display. I'm guessing there's something wrong in the CRT HV circuits, rather than the CRT having gone bad - unless that's one of the common problems with these.

Ed