Why is my Model 43 getting hot when I key up my radio? I am using the correct 100A element, (100W, 25-to 60 MHz), but as soon as I key my radio I check with a temperature gun and it instantly reads 160 degrees F. What is happening?
After consulting with one of our engineers on this, and he explained that your antenna is connected to some coax which is an unbalanced transmission line. He went on to say that normally, an antenna has a transformer inside that converts from unbalanced to balanced and he suspects that your antenna does not have this. As the coax starts to radiate, there is a current or voltage node at the 43 that is heating up.
One suggestion he had to fix this is to take a piece of 1.5" diameter PVC pipe. On the output side of the 43 wrap about 20 turns of coax around the pipe. This is a crude way to create a balun. If this doesn't work you may need to use a torroid to build a better balun.