[mikethedruid]

RGK20m3, You asked, "I don’t see how the 38-690 antenna input is balanced; although it has the 3 terminals (red, black, and ground), the black and ground are connected together and are connected to chassis ground. This is how my unit is wired, and is confirmed on the schematic." If you look at the schematic for these radios...
[Image: https://64.media.tumblr.com/defa8727b5ee...a70b99.jpg]
You will notice that the connection between the black and ground is REMOVABLE. It is a metal link between the black and ground terminals on the terminal strip on the back of the chassis. This hook up is the way it is used for a single ended (long wire) type antenna. This is OPENED, detached from the black lead so that the dipole antenna goes to both ends of the primary winding of the first antenna coil when connecting to a dipole antenna. In this form, I believe the link is switched to between the ground terminal and the number 4 terminal which is connected to the center tap of the first antenna coil. Don't let the switches throw you. Look carefully at the schematic and you will see what I mean. This is a 2 band radio, so it uses two antenna coils, one for each band, and switches between them. So, YES, the dipole antenna IS balanced. There ARE unbalanced dipoles, where one leg is longer than the other to make them better at receiving on different frequencies, but this relates solely to the construction of the antenna itself, and is not what we see here.