Wondering when to use a 4:1 vs 9:1 balun?
Use a 4:1 balun when matching a 200 ohm load to 50 ohm coax and transceiver.
Use a 9:1 balun, on the other hand, as your go-to for 450 ohm antennas setups.
⚡️It’s all about getting your antenna impedance down closer to 50 ohms.⚡️
#balun #ham #hamradio #amateurradio #hf #rf #radio #k4ogo
Hi,
I was wondering why antennas need to be matched to 50 Ohm, since the impedance of free space is around 376 Ohm.
Care to elaborate for a interested RF-Noob ? 😄
By convention, the impedance of the final amplifier stage in radio transmitters is 50 ohms. You get maximum power transfer from the amplifier to antenna when the load and source impedance match.
I'm familiar with impedance matching and the resulting efficiency. But still - If free space is 376 Ohm then why not match it to this impedance?
Good point. I believe that 50 ohms was selected because it was efficient and practical to build 50 ohm coax.
Antennas are actually designed to be matched to free space intrinsic impedance of 377 ohm. They are basically working as a matching network that converts that 377 ohm down to 50 ohm. Good question!
Great video. Thanks! 👍
