[R-390] R390(and "A") antenna question

[Flowertime01 at wmconnect.com]

John,

You can hang any antenna on your R390 any way you want.
Do not fool with Mother Nature, however. If the antenna is not in use, 
observe good operating practice, unhook the antenna from the receiver and ground in 
a way that will keep your home insurance agent happy. Lighting strikes are for 
real.

Hooking up two antennas at once is not a real problem. The type C connection 
by passes the first stage of tuning. You get a wider band of signal plus noise 
applied from the antenna into the first RF stage. While we would expect the 
next stages to filter that excess out of the mix before it gets to the ear, 
strange things can happen. This will not hurt the receiver. you may or may not 
get poorer desired signal and more noise. If its not there to cause 
interference, of course it will not cause interference. But it some strong signal is 
lurking around your megahertz of choice, you could get more noise than you have to 
listen to.

Even when you consider the antenna impedance mismatch going into the balanced 
input with one wire and the other side grounded, you often get a better 
signal.

Signal loss through a simple knife switch is not so much you can tell the 
difference in your ear. A relay or simple switch between receiving antenna's 
works well.

Loading the signal in from the balanced input antenna with the antenna from 
the C connector is not a real problem. Receivers were used with this type of 
antenna setup at times. There is a load from the second antenna presented. If 
you can tell the difference in your ear with your selected signal may or may not 
be a healable problem.

John, do you have the Y2K manual? 

Do you know how to run a single ended antenna into you balanced antenna input?

Roger KC6TRU over 56 and understand your memory problem.