Re: QCX antenna

George Korper

I'm building a QCX now for 20 that has a built in 49:1 transformer instead of the BNC
connector. NO COAX, just a lug to attach a wire  half wave end fed. 

I yearn to go way in the woods far from the stress and turmoil of noise.  And the TV. And the CV. And the politicians. 

Under a tree, i will hit the button and call CQ. If no one hears me, I will enjoy a picnic lunch,
stick it back in my pocket and stroll home. The micro switch will be fine for me as a key. 


Almost Heaven.....

On Tue, May 12, 2020 at 11:21 AM David Birnbaum <dbirnbau@...> wrote:
You are asking an interesting question that helps understand why an antenna is not just a piece of wire.  One way to look at this is that the antenna is not just some wire but behaves as if it were a complex impedance load at the end of the coax.  The cable then behaves the same way as it would if actual resistance and impedance were attached at it's end.

Another way to look at the combination of coax and antenna is to think of how the energy flows from the transmitter.  The RF generated by your rig travels up the coax and continues onto the exposed antenna wires.  The physics that describes this process make the energy flow essentially entirely within the coax until it reaches the antenna.  When it flows out over the exposed wires the physics shows that there is an electromagnetic wave flows away from the antenna carrying energy with it.  If the antenna dimensions are consistent with the frequency then essentially all of the energy from the rig is carried away by this wave, hopefully reaching whomever you're trying to reach.

Hope that helps


Join to automatically receive all group messages.