# Expanding range of RF sender (FS1000)

I send signals using the FS1000A, i.e. 433MHz. The module has a pin named "ANT", where I can solder an antenna, like a short piece of wire.

As the sender's range is not that far, I want to increase the range. Having basic knowledge in LC circuits, I thought that I could proceed the following:

According to the thomoson equation: I need ideal values for L and C to get best range for a certain (here 433MHz) frequency. According to the following circuit, the capacity is 7pF: So can I just connect an electromagnetic coil (i.e. coiling a piece of wire) having the right inductance L.

That would be true if it was a LC circuit. However, the antenna itself is a dipole antenna, so that I have to use other equations in order to determine the ideal parameters of the antenna. I know that the minimum length is λ/2 and every k*λ/2 (k in ℕ) works well. How does k influence the range? It is better to connect a electromagnetic coil instead of just a piece of straight wire, right? How do i determine electromagnetic coil's parameters (length, ...), as I cannot use the equations above for this purpose, can I?

• The circuit you have titled FS1000A shows a monopole antenna not a dipole antenna. Beneath all the misguidance I think there is a good question here such as, "A monopole antenna is resonant at 0.25 wavelengths and has well-known characteristics but, if it were 1.25 wavelengths, how well would it perform as a transmitting antenna (or a receiving antenna". Maybe you should ask that? – Andy aka Apr 22 '17 at 14:55 