I have an Eclips 7 with the Spectra modual and after 1 year of flying (alot) have never had any pary of my transmitter get warm to the touch. I cant comment on the different type of receivers due to I only fly with Hitec receivers. Like most other replies the modual getting hot is not normal and I would ground that transmitter until Hitec checks it out and repaires it. There service is top notch.