Resonant vs Non-Resonant Antennas (#538)

My son asked what that thing was over your right shoulder..had to explain the typewriter to him..he was perplexed..could not under stand that the printed paper came out immediately..I had a good laugh!!!!

I don't think his question was really answered. I think he simply wants to know if the antenna will radiate as good say for example with a non resonant 6 meter antenna using a tuner to a perfectly tuned 6 meter antenna.

Thanks Dave. One thing you didn't mention is the change in pattern between resonant and non-resonant, particularly with large antennas at higher frequencies. Thanks for all you do.

It might be easy to say the current is low at the feed point of non resonant antennas is because the Impedance center feed point would be very high creating a high voltage and forcing the current to be low. (P=IxE) voltage goes up Current has to go down for a given power. The losses are low on balance line because the capacitance between the 2 lines is low compared to coax reducing the losses for long lengths of open line vs. coax. Now it doesn't matter where the tuner is located at the antenna or at the transmitter end because the line losses are very low. There is a great book by Walter Maxwell called "Reflections Transmission Lines and Antennas" that took all the magic out of transmission lines and tuners for me"

Dave, Thank you for the YouTube programs and your QST articles. I look forward to both. I'm in an apartment with severe space restrictions. I wanted to see if I could possibly work HF on multiple bands using 100 watts or less. Center fed resonant antennas and verticals with radials just weren't feasible at my location. I now use a 71' non resonant sloper going from a 25' balcony down to a 6' wooden fence, a 9:1 unun at the high feed point, two 15' counterpoises on the balcony, 50' of coax, common mode choke at the and of the feedline going to a manual antenna and into the transceiver. Using this setup and 80 watts LSB from California on 7.204 MHz, I was able to work VK4KW in Australia on 10/1/21 at 10:30 UTC (3:30 am PDT). I've made made many contacts using just 1 to 5 watts. I regularly check into nets using 20 to 100 watts and have had extended QSOs on 80, 40 and 20. The SWR indicator on my little 100 watt amp and also on an external SWR meter shows 1 to 2 or better on all HF bands after careful antenna tuning. I've also tried a MagLoop but the non resonant antenna works better for me. My point is there's plenty of fun available on HF even for those of us with severe space restrictions if we're willing to learn about and experiment with antennas. Keep up your excellent work!

I guess I missed the part where you answered the question "Why bother with resonant antennas if a nonresonant antenna and tuner are just as good."

Would a cob web antenna work if it is mounted in a vertical orientation instead of horizontally?

Really good question?. My mfj269c has me resident and the swr reads 2.3 but the vswr reads 3.0 which is correct

EXCELLENT PRESENTATION

Thanks so much for the wonderful videos Dave. Your channel is a treasure. On this video, I feel like I’m missing a key point though. Say I have two antennas, resonant and non-resonant. The non resonant antenna has a tuner directly on the antenna base. Is there any reason besides tuner component cost that I should prefer the resonant antenna? I feel like your answer in the video was that they are equivalent. However, I never read about someone using a one foot random wire and a very expensive tuner to do DX 160m. That makes me think there is something besides matching impedance for low SWR that I’m missing. Thanks so much!

Appreciate your videos!

For a strictly receive only antenna does it matter if it is resonant or not?

Thank you sir!

Dave, would you please explain ", especially in connection with antenna efficiency and bandwidth. Listening to all these YT videos about different kinds of antennas, I usually hear that the antennas have low SWR, but rarely do I hear anything about how efficientt the antennas are. My dummy load has an SWR of 1.0:1. There are also "cloud burners" and "ground warmers." So, what is antenna efficiency, how can I measure it, and does it really matter? Thanks in advance David SV0SGS. PS I enjoy your videos and have learned much from them.

Thanks so much

Dave - Why do people say a nonresonant vertical shouldn't be resonant on any band? What's the downside to using a 1/2 wave 33ft vertical on 40 meters and higher frequencies? (With a transmatch/tuner)

I didn’t know you were working on Sunday!

Congrats on the QST gig!

thx, 73, dg2r?

Thanks for the info Dave - more for me to chew on as I mess around with wire antennas. I do things by gut/trial and error rather than theory and math and enjoy my successes and failures. I am now deep into playing with traps and seeing the effects they have on long lines both resonant and non-resonant together with un-uns ranging from 9:1 to 49:1 in value, together with ATU's. Some surprising results are emerging. As Yoda said - Do or Not Do ! 73 . M7BLC