I’ve been a HAM since Summer of 1989. Earned my General in 1992. Never had an Elmer till finding your channel. Thank you, David! 73!

Brilliant explanations, they're comprehensive, yet at the same time concise and clear enough even for non-scientists.

Slowly but surely these concepts are starting to open themselves to me. Thank you so much

Well Dave you finally did it. I’m dusting off my antenna books. Probably stay up all night immersing myself in theory.

Oh man. This one is thick. Gonna watch again tonight.

@DeltaXray444

3 жыл бұрын

Sure is, I've watched it twice already and I'm still lost at certain points, but it's about learning yes.

So much good info in this episode. Thanks for sharing with us Dave. I’m gonna have to learn more and come back here again to fully understand it all. Hearing that the loading coil helps keep things in phase was helpful.

Thank you. Great explanation. BTW, we do the same thing for 60Hz power lines. Motors are inductive and reduce the SWR or Power Factor (PF) to current lagging voltage. Equipment must be de rated, bigger unit, larger wire used for smaller job, when the power factor is bad. Also more heat. PF correction capacitors are inserted to compensate for this. Ever wonder why the power company puts forty thousand dollar high voltage capacitors on power lines ? Yes, they are switched items. Capacitors come online during the week day and go off at night because business add and subtract inductive loads. Mr. Casler, please do more presentations like this that bring multiple parts into play concurrently. 73, we hear you 5 by 5

Your videos are gold, David. Thanks for investing in this wonderful field / hobby.

Dave, people understand concepts visually better than any other way. One thing that would drive the point home about your definition of a dipole would be a diagram of the voltage distribution for a half wave antenna when a resonant RF frequency is applied. This would show one end having a positive voltage and the other end having a negative voltage. I think you've shown this kind of antenna physics in the past, but it may bear repeating. A dipole of any kind is exactly that, positive and negative charges separated by a distance. Even at the molecular level. Many people may remember discussion of charge distributions on molecules if they studied chemistry. Molecules having separated distinct positive and negative charge centers are called dipoles. So it goes for macroscopic antennas.

Nice job Dave!

Good presentation clarifying what folks often imagine/visualize in want to understand various implementations. It's as if we want to compare electrical energy/RF to light... antennas aren't flashlights or light sabers. :O

Love it. Love you Dave!! 🙏

Excellent, as always.

THANK YOU! I enjoy all of your videos, but at this point in my life this was one of the best. I really do need more technical education in this area. Mr. Casler, do you have any other videos you've done in this antenna theory you can recommend I watch?

A short antenna is capacitive and it has a radiation resistance which is small. Adding a loading inductor may bring the element into resonance but it does nothing to the radiation resistance. It stays low. So adding a loading inductor does not make the element electrically longer.

so does the resonance factor model into lumped-parameter representation for modeling/mathematical purposes?

Could that Isotrone antenna then be an extreme case of coil loading and a capacitive hat?

Hi Dave, may I respectfully disagree regarding the placement of the series loading coil. Taking the shortened quarter wave vertical example a loading coil at the base has by definition the highest current flowing through it, a more efficient solution is to mount the coil further up, at the top leads to a narrow "SWR" bandwidth but about half way up is a good compromise between efficiency and bandwidth. (In a practical antenna with a realistic coil). Naturally the bandwidth is related to the circuit Q which changes a lot with moving the inductor. Keep up the good work, 73

Wow - you are so helpful, Dave! I was a ham in high school in the late 60's, now getting interested again. I've been watching physics and optics youtube channels and then stumbled into yours. Amazing - better than most of the physics professors stuff. My question is about salt water as a ground. I am on Puget sound waterfront & could run a long line (150 ft or so) down to it. Would this be helpful in anyway? Many thanks, Retired Biologist Rob (long retired & obsolete WB6VAG ham)

You did a great job of explaining antenna theory!!! Thank you. After watching this video, I understand why some electronic technicians consider rf circuits CRAZY and do not want to work on rf devices or circuitry. Thanks again. N0QFT

I can't figure out why I find this channel so interesting. I know nothing about either electronics or radio. But would like to learn. I feel like it's a very secretive group though. That or I'm just a dunce.

@jeffdyer2393

3 жыл бұрын

Get your ham radio license there is a lifetime of learning and fun. You won't find a better bunch to do it with.

@garrysekelli6776

3 жыл бұрын

@@jeffdyer2393 thanks guys. I just figure that if I can accomplish it. It has to be done on the renegade level. Where I build my own antenna and all. Without the gvnmnt liscence. I notice yall have some sort of fixation about that slip of government cheese though.

@jeffdyer2393

3 жыл бұрын

@@garrysekelli6776 im as antigovernment as they come but if you do it illegally it won't end well. Hams are self policing they won't let you play with out the license. I promise the evil government knows where you and I both live ha. Its easy to get the license they won't require any info they don't already have. Just take the test .

@jaynone9262

3 жыл бұрын

If there is one thing ham radio operators like to do is talk. I am a general for 15 years . I know almost nothing about antenna theory. That video was way over my head. The only thing I know about an antenna is how to make a half wave . I memorize the Questions and answers. After that you learn by listening and asking questions . Its good to know these things but you don't have to.Almost always a hot topic and Dave explains it very well. Go get your tech and see how far you want to go in this hobby. We need all the amateur radio operators we can get.

@garrysekelli6776

3 жыл бұрын

Hmm. I think its a fake. A bait and switch. A brazen hoax. All of it. Don't bother buying the local currency. Unless you are a circus actor. Then for display they Will pay you to wipe ur bum.

Sorry, Dave, you misspoke... the Q goes up as the bandwidth gets narrower. 11:55

Ouch! THX.Dan.

welcome to the penitentiary

David: Your resistance becomes ... Me: Futile? David: *smacks back of my head* Shut up Trekkie. No. Ohmic! Me: Ooohhhmmmm. *ducks and runs*

@HitchHiker4Freedom

3 жыл бұрын

😄😅

Inductance