What is not good is to run the antenna close to parallel metal rods, such as all metal push rods going to the elevator and rudder. That seems to be a general rule of thumb.

And, as already stated, running the antenna straight as possible out of the receiver is what is best. The antenna length is somewhat critical in all of these systems. 72 MHz, for instance, uses a quarter wave length antenna which is 40.74 inches. (72.450 MHz). Antennas are normally cut for the mid frequency range of the band. So, never cut an antenna 'to fit' because it needs the entire length to operate properly.

On my 90 size pattern plane, when I was running 72 MHz (Airtronics RD8000 channel 11) I ran the antenna along the bottom of the fuselage. What I did was drill a small hole right behind where the wing saddle is, and passed the antenna through there and through a 'strain relief' so that it did not pull against the receiver. I then ran it along the bottom of the fuselage stretching it so that it is 'tight', then put a piece of either matching covering over the length of the antenna or a design color strip of covering. I then hit the covering with the iron. It looks good, and you cannot see the antenna, AND it is out of the way. See the diagram.

CGr