I started an AM receive antenna installation by laying out 200ft of RG6 coax. It's good coax with braid plus foil shield. The coax is on the ground, I shorted the end and connected the other end to my radio, there are no ground connections. The coax has 3 to 6 S units on my local radio stations. I want my coax to pick up as little signal as possible, because I want to install directional antenna on it.
Next, I tried grounding the far end to a 5ft copper rod, this increased signal strength.
Then I grounded the shield just before it enter the house, this increased signal strength.
Removing the far end ground and having just the ground near the radio didn't help.
I tried 3 different Chokes on the Coax at the radio, one monster choke is a very large potcore that I wound 15 turns of coax on, it has 25kohms of reactance at 1MHz. The chokes didn't help.
I wound a 1:1 Isolation transformer installed at the radio. That didn't help.
I could invest in some Quad shield cable, but nope. I already have over 1000ft of RG6.
The quietest so far is just the coax, no grounds. The chokes and transformer didn't seem to hurt, but they didn't help either.
I also changed the short at the far end to a 75 ohm resistor. That didn't help.
Anyone have recommendations on how to quiet the coax?