I would have to say underground communication connections are risky business. The wiring in some cases can easily get crossed, resulting in flash-burn and depending on the density of the reciever and the bandwith of the transmitter it's really hard to say.
In one unique circumstance, the ohm readings of a reciever couldn't pick up the signals correctly while information/data was being transmitted through a filtering devise, resulting in a faulty interpratation of what was being sent, shortcircutting the reciever all together.
In other cases, if the transmitter is working correctly, and the reciever shows no sign of returning the signal,the trasmitter overheats and stops functioning, and the reciever blows a gasket in it's flux Capasiter once the transmitter goes out.
Then there is also the case of Old wiring that has simply rotted.
The best transmitter/reciever connections that I have found are at the tip of my pole and the palm of my hand