Thanks for all your responses!

First off, I am attempting to auto switch/scan between two frequencies on AM. I have FM and internet streams sorted. The tuner is a Cambridge Audio hifi tuner with an RS232 interface for scanning. I don't recall the exact model number. The tuner can't be relocated as the server is controlling the frequency scan.

Obviously I didn't attach it to the FM coax input! I do have a small amount of common sense.

The coax cable was already installed, I assume it's standard CT100 75Ohm.

the loop was just one of those cheap plastic things they bundle with tuners.


somebody mentioned impedance matching, Thanks! I'm going to look into this if I can't already find a ready made 50-75Ohm antenna.

somebody else mentioned overloading with an active antenna....this is central London so there are all kinds of local AM stations....what kind of damage can be done??

again thanks for your input, you have given me something to work with.