I am just getting into radio, so bear with me. This is a very simple question about antennas. I have an AM 1 Mhz transmitter that I built. The antenna I am using is just a random wire antenna end fed. The wire is 18 gauge speaker wire that I have cut to what I thought was the right length for 1/4 wave operation (246 feet). Another antenna length site I looked at told me it should be 234 feet, so I am a bit confused. My problem is that it seems like the antenna has way too much reflectance because when I turn on my transmitter anywhere above half power, it starts to have feedback. The amperage draw of the transmitter begins to bounce up and down and then it stops working. I'm afraid it's going to damage it. I need a way to make the antenna less reflective (I think that's the problem). I have read about loading coils, but I thought they are only necessary for tuning an antenna that is not the right length. I always thought if the antenna is the right length it isn't necessary to have a loading coil. How close to the right length does the antenna have to be? Is a few feet ok or do a few inches make a big difference. Any help?
Thanks.
Thanks.