Question on AM BCB reception

[datainmotion]

I was driving through Glenwood Canyon here in Colorado today, trying to listen to 850AM out of Denver. Due to the distance from the transmitter and surrounding terrain, the reception was tenuos at best. As I approached a very large crane (with its boom nearly vertical) on the shoulder, the reception changed dramatically for the better (almost zero static). Technically - what causes this to happen?

 

[ka3jjz]

I suspect the boom was inadvertantly reradiating the signal, acting as kind of a passive repeater of sorts. It probably had spikes in the ground to aid stability, and this would have acted as an admittedly inefficient, but some, kind of RF ground.

I think the neighbors would mind putting something like this in your back yard to improve your MW reception, hi

best regards..Mike

 

[Tom_G]

Sounds like it was a capacitive-coupled BIG vertical antenna....

 

[SCPD]

I did this by accident last week. I had my shortwave portable (Sony 7600GR) outside near my coax to my HF antenna system.

When I got within a couple of feet of the coax line I got this incredible rush of RFI. I thought my coax was causing it.

It turns out the RFI was from a real but distant source. The Sony's antenna was coupling with the shield in the coax to make one big antenna. (The coax alone is 100ft long.)

 

[k9rzz]

Just like a parasitic antenna element found on yagi antennas.