Time for heat tape again...but should I use RG6?

Our attic is insulated as much as physically possible. But since the attic is living space, we still lose a lot of heat through the roof. Grand Rapids has gotten something like 3 foot of snow in the past two weeks, and that means that there is one thing on my mind--ice dams.

I've discovered something, though--the heat loss isn't nearly as bad as I once believed. I need to get some expanding foam to fill a couple of holes that I realized heat is oozing through, but when you get right down to it, our problems are less heat loss and more roof design. Our roof is a gable design that, if you look at it from the top, is essentially a + sign. That means 4 giant valleys in the roof. The ice dam problem is primarily in the valleys--but the valleys are so large that they collect water from a good portion of the roof. The dams build out from the end of the valley. That means that I don't need to address the entire roof--I need to address the valley.

I learned this from what might wind up being a potential solution--our new HD Satellite dish. The new dish had to be roof mounted, rather than wall mounted like our old dish. So there are cables coming down the roof from the dish, across the facia, and back into the house. And it turns out that the ice dam on that part of the house stops at the cable.

I don't know the specifics of the electrical properties of satellite cable. But it appears that the current on the wires are generating a little bit of heat. Just enough heat to melt the ice as it reaches that point of the roof and lets the moisture flow off of the roof. The fact that the dam stops at that point reassures me that the whole roof isn't melting--just selected areas. But, more importantly, if the low voltage current on the RG6 is generating a little bit of heat, that means that it might be useful as heating tape.

Heating tape is expensive, and you've got to get an electrical power source for it. RG6 isn't nearly as expensive, and being a low voltage source, I don't have nearly the concerns of getting power to it. But the best part is that I might not have to pay for the power at all--maybe the cable company already is.

Here's my theory--if the satellite cable is generating heat, perhaps the cable TV wire might as well. The cable company is already providing a current to my house--the signal is filtered (since I don't subscribe to cable) but the connection is there. And if the power provided by the cable company is similar to the satellite signal, then it should work just as well.

I'll need to test it. My plan is to get a length of cable (probably 20-30ft; I think I've got a scrap chunk that size already) and bring it to outdoor temperature before I begin testing. I'll then put the cable on the snow without anything hooked to it. In theory, it should just sit there. I'll then attach it to the CATV block on the outside of the house and compare the results--if my hypothesis is right, it should melt through the snow. If it does, then I just need to arrange a length in each of the valleys. If it doesn't work, I'll need to connect some sort of terminator to the end of the cable; a full circuit may be needed.

The other two possible explanations for the satellite cable working are 1. The satellite system's electrical properties are different. If this is the case, I may still be able to use the cable, and just power it from a satellite receiver (I've got a couple of old ones). The final possibility is that the cable is actually acting as a conductor from the inside of the house--if that's the case, then I don't even need a power source--I just need a long enough length of cable inside of the house to provide heat to the length outside of the house.

I'll post back when I have done some testing.