Spectran HF-8060 V5: Signal at 1.4 and 2.4 GHz
I have recently received a new Spectran HF-8060 V5 device. During my initial tests, I have noticed that a WLAN signal at 2.412 GHz reappears at 1.408 GHz. It is definitely the WLAN signal, as I can turn it on/off to validate that. This occurs with the RTSA Suite Pro, and on the handheld device itself. I have tested three different antennas. Furthermore, I noticed that changing the JTFA setting affects the presence of the signal at 1.4 GHz: it disappears if I use "frequency", but is visible when I set this to Standard or Time.
So, first of all, what is that effect? Second, how can I be sure that any signal that I observe is actually occuring at the current frequency?