I have been dealing with interference on a receiver with noise problems. Using a hand held Kenwood TH R6 receiver and laptop with SDR Council A3 software using a Funcube pro + sdr. I found a signal at 166,377.350 MHZ. This signal falls with in the band pass of the CTT receiver using the funcube sdr. The Funcube is tuned 166,376.007MHZ in the CTT receiver using Funcube FCD Frequency Control Program V2.002 software. It appears to me that signal is causing my noise problem. The source of the problem is a Cirrus 3560 LAN Switch located about 50 feet from the antenna and CTT receiver. The problem this is the switch router that provides the wifi signal to the Motus receiver.
The IT people in control of the switch do not see a problem since the switch is providing wifi to the area. I problem comes from the switching power supply in the switch that provided the various voltages to run the switch. I have test other switches ,routers and they do not emit the unwanted signal. I would like to replace the switch. I think this will have to be solved with people above my pay grade, I am a volunteer buy the way.
I also had noise problem with this station caused by old LED light. There are new LED light that do not emit RF signals. I also experienced a RF noise problem from a ventilation in near by building. The fan was replaced with a new one.
I am currently installing another Motus Receiver Station. I have surveyed the site and found 166.380 MHZ clean. I found a signal near the the 434 MHZ frequency caused by the DSL internet modem cable. I replace the un shielded cable for modem to wifi route witha shield and RJ12 shield cable. That did reduce the signal a bit. The problem is that the internet signal is provided by telephone wire cable. Fiber connection would eliminate the problem signal. The 434MHZ signal are more immune to noise because of the modulation which is Frequency Shift Keying.
Just my experience and I am still learning and may not have all my ideas of the noise problem correct. Fell free to contact me if you see any errors observations.
Glenn Pollock pollockg@cox net Omaha Nebraska.