Transmit 7.5 MHz center frequency

I’m not trying to get into a pissing match but you are wrong about several things. To “transmit” is to send signals in the air. Signals can get in to the air even without an antenna depending on shielding and decoupling being neglected. The Federal Communications Commission regulates radio, telephone and Internet. If you are transmitting as you say you cannot do that there. Clearly you are not licensed because you are crossing commercial and amateur bands as well as using more bandwidth than anyone is allowed in those frequencies except possibly FCC Part 15 devices. You may be surprised to know that 1.2 watts the Lime can produce at those frequencies can potentially travel hundreds of miles. Further there are volunteer teams that WILL hunt you down and warn and or report you to the FCC. Willfully continuing constitutes multiple crimes in the USA. So get your story straight if you continue to transmit as you have described. It really depends on if you cause interference but what you described is exactly that. Best wishes.