Resonant Frequency of Antennas - Jim W6LG

Update: I have read the article and enjoyed reading the explanation of using the dummie load as example of zero radiating but having a good SWR. Also the example of a folded dipole of having 160 ohms while having a good swr for example . One word popped into my head for a solution to reduce resistance down closer to 50 0hm's, and that was the use of a (balun) at the feed point. TU I believe I have a clearer understanding now.

Good read with some practical math.

 

I have not heard that term but, since this is a new year, we may hear a new term or two this physical year.

 

Hi,
I am Jim W6LG and I have a couple of quick comments. I think it is being implied that I mispronounced a word. I said 'resonant' many times. I did not say resident. I will go into more of an answer to that below.

For many, part of ham radio is learning about how things work. Those who do not have an engineering background will learn from others, by studying and by doing. They may very well have studied the answers to the exams and not understood the concepts of very simple things related to ham radio and electronics. They just wanted to pass the exam and get the license.

Many YouTube videos have lots of incorrect information. I try very hard to not make mistakes. But, I have made errors in videos. There is one glaring error in my narration that I will correct in a subsequent video.

When I would testify under oath, I had to think for a second when the clerk would say "raise your right hand. Do you swear...." I am very disphlexic(sp).

With respect to resident, I don't know where that comment has any basis. After I recorded the part 'in front of the antenna' I was taken to the Emergency Room and five days later had emergency surgery. While recording that video I was in terrible pain and just trying to make it go away. One guy wrote to me that I looked 90 years old. That is probably true. I do have the bones of a 90 year old because of severe osteoporosis. So he was right on. I use oxygen and a walker due to multiple pulmonary emboli that have damage my lungs and heart.

With respect to what I am doing, many guys have helped me over these last 58 years on the air. Often a very good friend would offer a simplified explanation about how something worked. So I am trying very hard in a friendly way to explain how I think things happen the same way. I do a lot of research for each video and often build prototypes or experiments. I consult with others as much as I can. But I still make mistakes.

Thanks for reading this and 73, Jim W6LG

 

Jim,

You did a fine job.

You didn't say 'resident'. That someone thought you said it indicates the origin of that issue. Not you.

Reactance is a mystery to most hams, who kind of get 'resistance' , partly because everyone knows about resistors, '8 ohm' speakers, and so on. They don't hear the term 'reactors' (that is, inductors and capacitors) so they make a huge disconnect and sweep the importance of reactance under the rug.

Resonance is a concept that is both important and irrelevant. That is because hams rely on SWR and do not understand that a conjugate match is often done to acheive resonance at the port. Many hams think that SWR is the be all and end all of antennas, which is a pity.

If you come up with a good way to describe 'electrical length', and ' radiation resistance' I am sure many here would enjoy such a video (for example). I would personally enjoy seeing it.

Keep it up and best to you in 2022.

73
Chip W1YW

 

Thanks Chip. Perhaps you and I could talk about that potential video. I would enjoy doing that with you.

73, Jim W6LG in Rocklin CA

 

Or the English Channel?

 

I watched the first minute................................................................. yawn

 

Having read through the comments responding to your video. In my view, the noticeable absence of constructive observations, underscores the need for additional videos.

Take, for example, this comment:

"Resonance is a concept that is both important and irrelevant. That is because hams rely on SWR and do not understand that a conjugate match is often done to acheive resonance at the port. Many hams think that SWR is the be all and end all of antennas, which is a pity."

Putting aside how poorly written and conceived this paragraph is. (And I could have chosen other quotations).

The crux of the issue is, when we're transmitting on any particular band, it is the operator's prerogative to deliver the maximum power to the antenna.

This can be achieved different ways. By carefully building, trimming, and tweaking your most recent home brew antenna masterpiece.

Or alternatively, an antenna that presents inductive or capacitive reactance can be canceled with the implementation of a matching network.

In either case, the 50 ohm output of the transceiver sees a low SWR, whether the matched impedance is transformed or (close enough to) purely resistive.

Both SWR and the concept of resonance are important considerations.

I remember watching your videos before I was a ham. I remember making contact with you when I was a new general on HF. One of your videos from Wolf Mountain was highly instructional in getting started in digital modes. With a practically antique Yaesu FT-747GX, and home made interfaces I was soon active on WSJTX. I remember watching your extra exam question videos when I was preparing for the test.

The main point I'm submitting here is that it's easy to criticize from the proverbial peanut gallery. It's a lot harder to produce videos that garner a 40,000 subscriber base.

Happy new year! You have my very best wishes in health.

And I look forward to ongoing future videos.

 

I subscribe to your channel primarily for the clear articulation and unique demonstrations. I didn’t notice any mistakes.

 

Would be my pleasure.

 

Hi Ben,

I am a high voltage kind of guy....

I am humbled by your characterization (of me) as ignorant, illiterate, and peanut-minor prone. The facts are otherwise.

Why don't you take a different tact and concentrate on facts rather than manipulating a narrative to attack people?

At no time did I criticize Jim on this thread. If that is your belief, I invite you to quote the statements that support this false assertion.

Now technically, for example, a dishy fact--

The insertion loss of a tuner more than offsets any minor increase in power afforded by mismatch, when the SWR is less than about 1.5:1 to 1.7:1 --so your comment is false in fact.

A tuner exists because solid state equipment uses transistor power amplifiers which require low SWR values, usually less than 2. In the era of 6146's, 6HF5's, and so on, a tuner was a relatively rare device for use with a transceiver . In fact, I did not own a tuner until more than 20 years of being licensed, coinciding with my first solid state transceiver. That experience is typical and not anecdotal.

Here is your comment on my prose...

"...how poorly written and conceived this paragraph is"

As to my solecistic (alleged) demonstrable incompetency: I invite you to rewrite my paragraph (in red, above), post the edit here, and then demonstrate how a professional editor should properly write that thought and capture its meaning to a wide audience,through your superior corrections. Feel free.

73
Chip W1YW

 

The term "73's" (not 73) was used exclusively during the first few decades of amateur radio. I have a collection of over 200 QSL cards from the 1920s. I've attached examples showing the use of 73's in 1923.

Perhaps we're wrong in suggesting that the double-plurality of "best regards" is wrong? I'll stick with the term used by our forefathers - grammatically right or wrong.

Paul, W9AC

 

Thanks to you Chip! I did have a tuner a few years after I passed the General Class Exam at the FCC Office in downtown Los Angeles in 1964. It was a Johnson Viking Matchbox. I had constructed an open wire feedline using ceramic insulators and installed it up the hillside in Burbank to a Mosely CL33. I had installed tower on City property behind our home on Amherst Drive. The City looked the other way because I was part of the Civil Defense organization. That antena worked until I set the some cloth on fire where I had passed the line through an open window. It was a metal casement crank out window. My next door neighbor was a Catcher for the Dodgers; Norm Sherri. He saw the fire and began yelling at me as I tried to stamp out the fire before it burned into the brush. Two doors up was his father-in-law Don Brockway 6PL. Don got Norm to calm down and not tell my parents about the fire. SWR meters were pretty much unknown to me at the time. A wattmeter was out of the question. In any case, I often learn a great deal by doing something. Those learning experiences may set something on fire. In this case, I learned about standing waves the hard way. 73, Jim W6LG

 

On the QSL card it says "Best 73's" and this is incorrect. It was the number of a message as you know. So what he had printed would be best best regard's. I know that you it should be simply 73 as listed on the chart on the wall of the telegraph office. I had an original chart for years but it was lost in my recent downsizing. Paul from me 73. Jim W6LG