Part Three RF Chokes: RF Man Discusses Long Wire Antennas, Unun's, RF Chokes, and Antenna Tuners. 

Great information. Well done with the diagrams and demonstrations. It would be more pleasant to view with a fixed camera. Thank you for your explanation.

Excellent video, thanks! I appreciate your work in experimenting like this and sharing your knowledge. Cheers!

Great information--working on end-fed long wire...unable to tune

Thanks for the presentation. Enjoyed it..:)

Surprised. A fairly accurate tutorial.

Great video. Very useful information. Thanks for posting. Barry, KU3X

Thanks for the likes!!

Good content. Would have enjoyed it much more if I had taken my anti-motion sickness medicine first.

Thank you for the videos. I am fairly new to the hobby and have a question: I am running a G5RV. To eliminate all RF, would I use a 1:1 balun at the antenna feed point and also a 1:1 Unun just before the tuner? The G5RV confuses me a bit.

Great job with all your videos. Is there any benefit to gluing 2 or 3 ferrite donuts 43 and 61 together in the 9 to 1 other than increasing the power you can put through them. I have heard of coax line isolator that uses several different ferrite numbers. I'm going to build my own 9 to 1 unun for a multiple band end fed and coaxial line isolator / rf choke. To save a lot of money i hope and get better quality. Thanks again. AA4CP Chuck Port Salerno FL

It would be nice to see the amount of reactance verses resistance generated by the shield, perhaps look at a Smith Chart sweep plot. You don't want the choke reactance canceling any reactance introduced by your coax run from the choke to your load (transmitter/receiver). That could increase the common mode current. Am I thinking about this correctly?

I was hoping to gain some understanding as to how it is that my home-brew EFHW antenna, cut to 80 M gives me better than 2:1 on all the bands, 80 thru 10 (havent't tested the new frequencies as my older radios don't support them). I am not complaining, but it throughs a wrench into the way I understood this. The EFHW, with the infamous 49:1 UnUn, was only supposed to resonate on harmonics of 80 M. 73 es TNX, Marc

Would there ba an order in how these are inserted into the coax line ? Subscribed today, just found you. Great info

You may have said it and I missed it, but which ferrite mix are you using here, the 31 or the 43? I see the extreme dip to - 60+ db at approx. 15.4 mhz. What causes this? I have a monoband vertical (Solarcon 99) that gives me rf in the shack that I would like to attenuate sharply at the desired frequency (27 mhz) but I don't have the necessary test equipment like you have in your video. I'm wondering if the number of turns through the toroid determines the specific 'maximum dip' frequency. Or maybe how tightly it's wrapped? I never had any trouble with thia antenna at my previous QTH, where I had more room, but where I am now I have to have to have the antenna close to the house. And semi-hidden (HOA). I wish I could put up my homemade yagi again, but that ain't happening here! Any help would be appreciated.

I have watched videos where they used plastic coated 18AWG wire (non shielded) wires connected into a PL239 - would you expect to have high attenuation on both wires and not just the shield? What would that do for your TX/RX into the shack?

If I use 2 conductor wire would it add impedance to the center conductor since it is not shielded like in coax?

Your balun and unun shown at the 6 minute mark in your video is the same thing! By switching form 2 seperate wires to zip cord doesn't change a thing in the operation. Your 1:1 unun would be much better off being wound with Teflon insulated coax instead of zipcord. Also, a 9:1 unun isn't designed to feed a random wire, it is designed to feed a 450 ohm load and is most efficient when feeding a 450 ohm load. A random wire may be 450 ohms on a few frequencies, but the impedance varies sometimes greatly as you move from frequency to frequency and band to band. Yes, the tuner may be able to match it, but coax is also most efficient when operated into a matched load and putting the tuner in the shack with a long run of coax, the losses can be quite high in the coax and the unun and you end up with a not so efficient antenna system. Yes you can make contacts with it, but you may very well be missing a lot of signals to!

Question, can I stack a 43 and a 31 together and make 10-12 internal passes without screwing up the intent of the choke performance?

I've always understood that a 1:1 ratio indicated an RF choke, with no impedance transformation, while a balun would have a transformation ratio of 4:1, 9:1, 49:1 etc. Now I'm confused.

Is there any way I can get a diagram of your UNUN RF Choke? I need to build one.

In the first part you said most tuners are t networks question could you use a tuner for your input and output circuit for a tube amplifier I'm wanting to do this if you could do a short video explaining some of how to do this I would appreciate any information on this.

Rookie

Would a type 61 core be OK for the choke? Thanks again!

*

The drawing at 6:30 and 17:00 appear to be wrong. Am I wrong?

Un

Unwatachable. Constant camera motion caused motion sickness at about 8 minutes. Sorry . Narrative was good.