Rather then trying an antenna modification that might not work, consider adding a cutoff relay to your receive antenna. There are two places where you can access a transmit indication from the K3. One is the KEY OUT jack on the back of the K3 which may already be in use for an amplifier. Another is pin 10 of the ACC 15 pin connector. The former is rated for 5 amps while the latter is rated for only 10ma.
There is also a $38.00 RF limiter available from ICE that may solve the problem. Model 196.http://www.iceradioproducts.com/rfswitch.html#1
Let's think about this. He said:
My question is - Should I put a coax choke-like a ugly balun- on my inverted vee antenna. I am having trouble with it interfering with my Beverage antenna. What I mean is when I transmit above 50-100 watts of pwr it I hear my rx antenna board clicking in the back of my K3. I figure the rig is protecting itself from receiver overload. It only does this on 160 meters. My Beverage antenna goes from the base of my tower to the northeast 1000 ft.
My advice would be to get the Beverage away from transmitting antennas and tower. Here is why:
1.) 1000 feet is pretty much a waste of wire length. Earth losses under the antenna would make current at the far end almost nil. You'll actually do better with it between 600 and 800 feet long for 160.
2.) If you brought the end to the tower, and near the HF antennas, you are working against the goals of the Beverage. You g brought the end right near where it will couple to everything and pick up noise. Even 200 feet from a resonant 160 antenna can be a problem for a Beverage, in some cases.
3.) If you disconnect the Beverage, better be sure it always works. It takes a heck of a signal to trip the relay in the K3. I have RX verticals 200 feet from my TX antenna, and I can light a neon bulb on those antennas, and they don't trip the relay in my K3.
If it was my setup, and I had a Beverage attached to a tower and right under TX antennas, I'd move the feedpoint even if it was not bothering the receiver. That's just a bad way to install the Beverage. At least get it 100 feet or more from the tower.