Aerial placement

[JewelHanda]

Hi...the warning states that during the adaptive frequency run the minimum frequency range that you set ((freq_max-freq_min)/60) was reached.
In a first step I would suggest that you check plot the results as a function of frequency and make sure that they make sense - e.g. S11(f) should not be greater than 1.
If you want to investigate further, you can try rerunning the simulation using a smaller minimum frequency increment and compare the results to see if they are the same.

prototype pcb

[ray schrauwen]

The length of an antenna is 1/4 the wavelength of the desired signal to receive. The older transmitters, running 500khz or so, needed at least a 20" antenna. As the frequency increases, the antenna grows shorter. I agree that you could modify a coax for GHz reception. But that wasn't the point Paul was making. You still need 1/2 a 1" unshielded portion even for GHz. That would be trick to raise the reception point over the boat and still make it effectively receive the carrier. My reciever has the antenna inside of it on a PCB strip line. It's attached with Velcro on the under side of the deck, pointing up. I'm getting full range for a boat, but wouldn't trust it in a plane. Your cell phone has the same type of antenna. The benefit of a PCB strip line is that you can set the capacitance of the antenna, and make a better tuned circuit. I have designed antennas for a living, working for Wilson Electronics. If you use a coax, you should be well versed in antenna theory or you could easily make a unidirectional antenna out of it, something you really don't want. These antennas need to be omnidirectional in RC craft. Some of these problems being posted could be suffering from that.

What about Tactic radios? Many of their Rx's have no antenna. One friend uses Tactic for everything and even in a carbon hull racing ovals no problem.

[MadProps]

What about Tactic radios? Many of their Rx's have no antenna. One friend uses Tactic for everything and even in a carbon hull racing ovals no problem.

I put a tactic receiver with 1/2 antenna in my race quad and it flys 100yds and falls out of the sky, tried another with same results
cheapo flysky works better