Thursday, December 16, 2021

Advantest R3361B Spectrum Analyzer shows two side bands 10KHz apart from 0Hz (aka: PSU recapping)

I was having fun performing some modulation measurements on my sig-gen (HP8640B) by using my R3361B as a modulation analyzer ...when started to note a tedious 10KHz AM modulation on all signals, even in CW (I mean with all 8640's modulations settings turned OFF). Using a different S.A. I verified that there is no modulation whatsoever in the 8640's CW signals. The sig-gen is not the culprit.

So I went trough section 4.3.1 of the R3361B's service manual to check the side bands around 0Hz of my S.A. Pictures show what to expect and the actual I've got. It seems like my L.O. is AM modulated @10KHz making precise measurements (low SPAN and low RBW) difficult if not impossible..

   

The problem has been fixed with a full PSU recapping. Here is the result:

Monday, December 28, 2020

An Italian VOM: Chinaglia "Cortina Major"

I own one of those superb VOMs.

It features 40kOhm/Volt both in CC and AC, not a so common feature.

Googling around I realized that the schematic diagram is not available on the net.

Here it is:

Chinaglia Cortina Major
Please note the galvanometer specs: 17.5uA FS!!

Enjoy.

Emanuele.

Thursday, April 2, 2020

how to recover a ck77 3.3V camera module from a scrap PC

Got a ck77 94v-0 3.3V (model 5SF001N2F) camera module out of a scrap ASUS K550V. It shows a Realtek RTS5806 chip on board.



ck77 94v-0 3.3V (model 5SF001N2F)
ck77 94v-0 3.3V (model 5SF001N2F)


There are plenty of instructables posts and videos out there teaching how to recover webcams out of scrap PC.
Unfortunately none of them covers the webcam module I have got so I had to find myself the pinout needed to successfully connect it to a USB port.

Here are my findings: