Vertical Antenna Efficiency - A Basic Rough Guide

[@acestudioscouk-Ace-G0ACE]

This is excellent! Very well delivered and explained, as only a professional educator can. Great graphics and well laid out. The information here would be the precursors for chapters in a future book by any chance. Could and should be. You have certainly changed up a gear here! Thanks for your hard work.

[@timg5tm941]

Wow, thank you! Glad you enjoyed! 73

[@hectorpascal]

Excellent tutorial, Tim. I shall point my Uni students towards parts of it when we cover antennas.

[@timg5tm941]

Thank you Hector, that is very kind! 73

[@8thspirit]

Amazing. There is no words other than that. Best content around.

[@timg5tm941]

Thank you that’s very kind 73

[@hoggif]

Thanks for a vary informational video! Very clear and easy to understand and it included a lot I've never thought of or understood about antennas. Looking forward for the future episodes! 73

[@timg5tm941]

You're very welcome and thank you! 73

[@MM0OPXFieldRadio]

First class Tim. I've wanted to do a similar video for some time but always put it off for fear not being able explain it right. Look forward to the follow ups.

[@timg5tm941]

Glad it was helpful Colin - thank you!

[@PatAutrey]

Thanks for this ! I always wondered what determined efficiency.

[@timg5tm941]

Glad it was helpful! 73

[@tombaffa9374]

Well done! Easy to understand now. Thank you

[@timg5tm941]

Great to hear Tom thank you 73

[@oldfartonabmx2122]

Great video Tim, I look forward to the sequels. I'm planning on building a vertical antenna using a squid pole to mount on top of my all steel shed (approx 14x10 meters, American barn style). I'm hoping it works well and I'm hoping I can get it up one day while the wife's at work and hoping that the old "seeking forgiveness rather than permission first" idea works !!!! I'm also thinking or building a big, low, loop antenna to use as a receive antenna in conjunction with the vertical. 73

[@timg5tm941]

That's a great idea - get it in the air and then pray!! 73

[@TomG2NV]

Nice Job! you've made a complex subject very accessible. I'm looking forward to the follow-up videos. I have long had my doubts about ground mounted verticals, out in the clear, a hilltop in the countryside fair enough but in an urban/suburban setting, surrounded by Brick buildings/ tin potting sheds ect one can't help wondering how much radiated RF is soaked up by domestic surroundings!

[@timg5tm941]

Awesome Tom - thanks mate.

[@g0fvt]

Very well presented, and unusually I agree 100%. It is very handy to have a low SWR antenna particularly for those of us that remote control or radios. But there is precious little point otherwise. I think my HF antenna feeder maybe as short as 50ft, if my SWR was 4:1 on the 40m band the additional loss in the feeder due to SWR would be about 0.2dB. My original radio system (very limited) measured at about 20 ohms. So as per your example the efficiency due to ground loss alone woud be down to somewhere in the region of 60% driving a quarterwave vertical. Extend the vertical to 3/8 wave with a series capacitor and the low angle radiation will improve by more than the SWR loss in the coax plus the ground loss will be reduced. Efficiency should now be in the region of 90%. close to a 2dB improvement despite the high SWR...

[@timg5tm941]

Great points - thank you!

[@evertwenderpirt6328]

your initial equations have the 100 in the denominator.

[@WECB640]

Tim, this is your BEST video ever! Full stop. I'm elated to see this discussion and subsequent education of your viewers. Thank you also for not jamming every aspect into one video, but instead making this a multi-part series. The information is vast and needs to be broken down into smaller bits., and I know you'll do a great job at that. Can't wait till the next part is ready for viewing. 73 OM

[@timg5tm941]

Wow, thanks! I am glad you enjoyed it. I have really enjoyed the research 73

[@qutips33]

good video. interesting this with loss in an antenna and ground loss, but how about using a gp antenna for 40 to 10 meters with coils so that it does not get so high and with radials then you get the ground plane up in the air and no loss towards the ground and tun the antenna for your frequencies you are going to use it must then be a very good antenna

[@timg5tm941]

Yep - elevated radials are pretty efficient and you need fewer of them

[@ouijim]

Currently experimenting with TRUELADDERLINE Doublet Antennas. Using formula dimensions from L.B Cebik W4RNL, specifically 44 feet Antenna and 50 feet feedline, performance is the best I've had (by reports and receive signal) in comparison to EFHW and Random Wire antennas and Random wire vertical. Also used TRUELADDERLINE 22 feet doublet antenna with 50 feet TRUELADDERLINE feedline portable at much higher and open area and results were outstanding yielding 3 S units increase signal (Transmit and Receive) using 27 watts from FT-891 or about Half Power used from Base Shack. Doublet is best antenna for me this side of Yagi-Uda Antenna ; )

[@timg5tm941]

Very useful information James - thanks 73

[@alanjones3873]

great vid, yes more please. I know my antenna is inefficient but not by how much. 10.6m endfed in inverted L (about 3 up 7 along at 10m high 50m mixed length radials) . So on 160m it cant be good but my 991a tuner matches 10m to 160m . How much gets out? EMF calcs say I need fo keep people away but if only a few watts get out is it below EMF regs! NB FT8 I get all Europe, EastUSA and have hit China and Japan.Cant wait for more.

[@timg5tm941]

Thank you - I hope you enjoy the others too 73

[@leonardogalloiz3atv474]

Radiation resistance has a special definition. “The total power radiated in all directions divided by the square of maximum net (or effective) current causing the radiation” This implicitly means that the radiation resistance should be referred to a current node. Further, the radiation resistance is a consequence of the geometric structure of the antenna. This is the reason a vertical half wave dipole has the same radiation resistance of an end-fed half wave antenna.

[@timg5tm941]

Indeed

[@francoguanziroli7867]

Hallo Tim, excellent video! My goal is bettere performance on 10-15-20m with 2 vertical EFHW with 49:1 transformer elevated from the ground using fishing poles: the first 10m long for 20&10 and the second about 7,2m for 15m band. Do you think that 2 resonant radials for band is a good solution for loss optimization? PS: now i'm using an 8010 EFHW ground mounted with 49:1 and 15 radial @4m long

[@timg5tm941]

Hi Franco - those two antennas will work very well!

[@hamshackleton]

Hi Tim - you could include an explanation of why a Minus number of DB's is better than a plus number - I never did understand that! To my mind, a minus number is less than zero, so how can a bigger minus be better than a small one?

[@timg5tm941]

Is it? I need to revisit my video to see where that was

[@bitemykrank1970]

Efficiency is simple, add another few kW of power into the antenna and you get out better. 4-5kW on CB AM ch19 is standard in the US now, you can hear it in Australia most days.

[@timg5tm941]

That's one way!

[@markramsay6399]

Great video Tim ! Mark, 2E0MSR

[@timg5tm941]

Thanks for watching Mark - cheers!

[@andrewhill4226]

A little heavy going, but I believe most of it sank in LOL. Thanks Tim.

[@timg5tm941]

No worries - thanks for watching 73

[@briantrask8173]

Tim, great video, I will be looking for the follow ups. I do have a question regarding making a mono band 1/2 wave antenna for the 10 meter band. You mentioned having a L C Network at the base. I was wondering how I could go about doing that. Is that something I could buy already made or do I have to make it myself?

[@timg5tm941]

That is correct Brian - there is a manufacturer in the UK - UK Antennas who make high quality LC mono band half-wave antennas.

[@PatrickKQ4HBD]

I seem to have more questions than answers now. I've clearly got to do a lot more study.

[@timg5tm941]

Ah the joys of the hobby!

[@moozoowizard]

So dig a 1m deep 40m by 40m hole. bury a large amount of chicken wire then buy bags of salt and cover the area with it.water it in then cover it all up and put your vertical up in the middle it's should work great... Right :) I'm kinda wondering if anyone has tried this crazy idea.

[@timg5tm941]

If only it were that simple!

[@brianfields4479]

Not quite that scenario, but because I just wanted to get on the air without all of the reading. I put up a 5m painters pole and layed out some radials, just to see what would happen. It's still there and it works dx everyday, zl to eu , so sometimes it's simpler to suck it an see. Well done tim for all his work for those with more patience than me, 73 zl3xdj

[@samgrieg]

Salt really works, that's why it's suggested as a solution to improve ground rod conductivity. Should work same for radials.

[@hamshackleton]

@@samgrieg - but it will kill all the XYL's plants! :-(

[@M0RMY]

Sounds like a great idea, but sadly chicken wire rusts faster than a Friday afternoon Vauxhall Viva. However a copper based mesh is a great prospect.

[@markwhittington8198]

Hi Tim - Top video! If you haven't seen it you might also be interested in the presentation that Ted Rappaport (N9NB) gave at this years Dayton Hamvention Antenna Forum (kzbin.info/www/bejne/iIu8qmdqpsabe6c) Keep up the good work and thanks for the QSO recently. 73s Mark (G1VGK)

[@timg5tm941]

Thank you Mark! I will check this out. Good to work you 73

[@sc20910]

Cringing every time you show the x100 in the denominator

[@timg5tm941]

You’ll get over it 👍