Hello Peter,

But more important, it works better at a lower supply voltage.
So, for use with a 9V battery, the BFQ19S is recommended.
At 12V you will not notice any difference.

In this case the antenna interface can be omitted.
It is best to place the battery at the foot of the mast.

There are more options, like using CAT5 cable, isolating transformers etc.
However, it all depends on your specific location.

73,
Roelof, pa0rdt