That manual is pretty clear about it:
* there are two antennas: primary antenna (external), RX2 antenna (internal)
* RX2 antenna port is RX only.
Both do an impedance test for open/normal/short, both expecting ~10kOhm impedance to be in normal state.
It's possible that after disabling the primary antenna, because the RX2 antenna still receives a good signal, it thinks it has strong signal strength, even though it cannot transmit. (It doesn't know it can't transmit, and all it can measure is what it receives)
So you're reading the secondary RX2 as the internal, not a second external? Hmmm. You raise an interesting point.
If the internal antenna is not
capable of transmission, then that's very relevant to the privacy concerns. I read the manual's comments on RX2 as well (regarding receive-only), but I read that as applying to the secondary
external antenna connection.
The displayed "signal strength" icon (X out of 5 bars, small antenna icon, 4G symbol) on the screen is indeed a black box - no definition of what it's actually measuring. (TX/RX, 4G, any cellular signal, etc) I'll just call it "measured signal" here.
The secondary thing that leads me to believe there are 2 external antennas is:
- The base measured signal (from a parked reference location) is
3/5 bars with nothing connected to the cellular antenna ports on the head unit.
- The purple FAKRA connector (clearly primary) raises measured signal to
5/5 bars when connected by itself with no other connectors attached to the head unit.
- The pink FAKRA connector (I was assuming secondary RX) raises the measured signal to
4/5 bars when connected by itself with no other connectors attached to the head unit.
This may not be conclusive, but it would be odd if the pink FAKRA connector repeatedly improved the signal strength if it
doesn't serve as a secondary antenna.
