Even if a glow igniter works with DC curent, if there is a loose conection or wire, there might be some sparking at that point...now a spark covers the entire rf spectrum, wich might cause your radio trouble...maybe you guys never heard of it, but a spark plug installed in front of your car, and connected to the engine is the best rf radar jammer there is...

The only other thing I can think of is a bad ground in your radio system...recheck your connections between rx and battery.