Recently I have had a rash of interference problems, to the point of nearly losing two different planes. I am seeing the problems on four different receivers and two different channels. I have always had one area of the field where I got a momentary glitch, but now the problems seems to be in 3 distinct places- two of which are on final. The problem is compounded now because I am flying tail heavy 3d designs. What would be an almost un-noticable glitch with a sport plane is a near wreck with a tail heavy 3d ship. Some other 3d fliers have reported these issues as well. I am sure that the fact that 3d planes have such extreme throws makes them much more sensitive to glitches, thus the 3d guys are the first to notice these problems.
Last month, I experienced complete loss of control on a pattern ship that lasted for about 4 seconds. I spent some time with an Icom R2 and a Hobbico Frequency checker and I have some results I'd like some informed opinions about.
With the R2 and a rubber ducky tuned for C.B. use, I just happen to hear some chatter on the very two frequencies I fly. On one of the two channels, I can plainly hear a higher noise level with the R2 in FM mode. If I put the R2 in AM mode the noise is almost intelligable. If I put it in wide FM mode I can hear two radio stations, sometimes intelligibly. The primary offender transmits at 91.5 FM. The Hobbico checker shows nothing at the field, although I have yet to try an external antenna there.

The field is roughly 3 miles line of sight from the transmitter farm for 3 local T.V. stations and a couple of radio stations.
I live about one mile from these transmitters. At home, the Hobbico checker is seeing the interference one channel away from both of the channels I fly without ANY external antenna. With a 12 inch antenna it is seeing activity on about 1/2 the 72mhz RC band. With a 36 inch antenna the entire band lights up. My Icom "hears" the same radio station (in AM or WFM mode) on almost the entire RC band with the C.B. rubber ducky. I can set the squelch at the highest setting and it still hears the station in any mode but FM.
When flying a park flyer near my home I can only get about 100ft. of usable range as well.
I am flying JR ABC+W single conversion FM receivers. Dual conversion users seem to have minimal problems.
I have purchased a 770 pcm receiver in hopes of alleviating the problem, but I am planning on changing channels as well. How much should I read into the "interference" I seem to be seeing with the R2 and Hobbico checker? By evaluating which channels "trigger" on the hobbico checker with Varying antenna lengths could I determine which channels are the cleanest?
I have a pattern contest to attend in a week and I need an immediate solution. My last five practive sessions at this field have all been a loss due to the issue I'm having. Any advice is greatly appreciated!