After the dish controller rebuild, now I’m updating the X-Band downconverter.
One question that rounds over my mind some times is how good is the phase noise of the Ma/Com brick that I’m using in the downconverter as local oscillator. The last year I was puchase in eBay a nice Ferranti brick oscillator.
Phase noise test
The two units are locked to a 10MHz rubidium reference. After some tests and tuning, the Ferranti beats the Ma/Com, it is much clear:
Macom vs Ferranti PN
Test Seup
Starting the new season, I’m doing a lot of improvements in my system. Now I’m rebuilding the dish controller. The idea is get more mechanical precision and reduce the backslash. I hope improve the security too.
Dish Controller
The selection of the speed and motion of the linear actuators was controlled by a ADAM 4068 relay module. It has been changed by a ADAM 4052 Digital input/output module, to reduce the reaction time and reduce the backslash. Now the ADAM 4068 relay module is used as watchdog to stop all if the comunication with the linux server is lost. I added a Emergency stop push button to the controller box.
Inside Dish Controller
Finally I added a RFI EMI power line filter and some ferrite core filters to reduce the RFI noise that was generating the controllner in HF.