Router uses either internal antennas or external ones.
Selection is automatic, but there could be also setting for manually locking it.
You might get some signal improvement just by turning router to point different directions.
At least that could tell direction of closest 4G transmitter, if you don't yet know it.
When first opening LTEWatch you'll likely want to change language to English.
One of the buttons opens settings, where you'll see German flag in selection list box.
Also might need to change that first setting from standard to password.
Then just check and if necessary correct router's IP address and give password. (default should be admin)
After few seconds it should start giving values with those graphs being especially good for checking changes in signal level.
Different cables have very varying attenuation.
Page is in Finnish but it has good table showing attenuation (decibels per meter of cable) of different standard cables at various frequencies:
https://www.satshop.fi/liittaminen/3g-4g-gsm-wlan-kaapelit.html
That RG-174 would really suck.
If you have antenna with 5dB amplification, three meters of RG-174 nullifies that at 1800MHz.
Must be some long resistor instead of signal cable...
