DX does have the aluminum tubes for building a directional antenna, the 20 meter I’m building is cheeper to build than to buy , about 1/2 the cost and teach my son patients ,accomplishments and maybe the value of a dollar..thanks for the DX tip.

There are so many details that matter here, each situation is different and generalizations often break down. For example, ground is not a zero ohm RF sink, it has considerable resistance at RF, so current will divide, some will still flow toward the radio. Each time current has an opportunity to go two different ways, it will divide based on the impedance of each path. Adding beads or baluns will reduce the current flow on that path, but depending on the actual values of the path and balun impedances the current will divide, and substantial current can still flow, especially with loops of coax or a few beads which are weak and present minor impedances to the flow. As the frequency (wavelength) changes the impedances change substantially along the conductors, so something that works in one part of the band may not work in another part or on another band. Some tuner designs are much better at balanced outputs than others. The fun and magic of radio. 73 de w6akb.

With my coaxial end fed half wave (EFHW), I use an Alpha Delta lightning surge protector affixed to the outside station ground rod . Never had any issues with common mode currents. Thanks Dave for the technical tips and good videos. 73, AC3HT

Thanks, Dave for another video that taught me something!

You probably shouldn't rely on just the lightning arrester to block common mode. That'll waste that current by warming up earthworms, with a little bit of it radiating from the coax itself. Stopping the current at the source will put that energy to better use, sending it back into the antenna and/or transmission line, where it'll actually radiate (perhaps after a bounce back to the transmitter).

Hello Dave and thanks for this information. I had somewhat of an understanding about common mode on coax but was in the fog about it on window line. You cleared that up. One question has been when using a dipole with a window line (450 ohm) feed, it seems the recommendation is to use a tuner with a 4 to 1 Balun. Since the system is a 9 to 1 mismatch why not recommend a 9 to 1 Balun. I have to be missing something. Thanks for sharing your knowledge. Tom

@richardwesterman5773

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Transformer baluns make lousy baluns for several reasons. Use a 1:1 current balun.

Agn a good vidéo "OG". 73

Dave. Do you have any scholarly papers on common mode RF Feedline currents?

Is there a better way to suppress common mode currents on balanced feedline than letting the tuner absorb them? And equipment is electrically grounded (not RF grounded) so that may not 'drain' all CMC before it gets into everything else in the shack.. Great content, Dave! So much appreciated.

Hi Dave, I feel very sorry to make my contention on the contents of this video. Please prepare well and present the correct information. Many people have very high hopes that they would be informed right. De VU2RZA

@narquattslagg9708

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Your comment is not very helpful. Please provide corrections.

Don’t change your music. Please