I’ve so enjoyed this series of videos Tim. As an engineer that finished university studies in 1984 you make me feel like I’m back actually learning something. Of course I’m a structural engineer (I design and build the towers). Thanks for sharing your knowledge my friend. It’s much appreciated.

@timg5tm941

Жыл бұрын

My pleasure Walt and thanks for watching !

Thank you for the series on verticals.

@timg5tm941

Жыл бұрын

My pleasure and thank you for stopping by

Its Dr Tim ! Your academic teaching style really stands out in your videos, you build on previous knowledge, and then take it in an interesting new direction - lovely stuff, thoroughly releaxing and enjoyable listening for a sunday afernoon/evening. :)

@timg5tm941

Жыл бұрын

Thank you Al!

Wow, that was spot to take in. Definitely having this in my favorites to come back to! Thank you sir!

@timg5tm941

Жыл бұрын

Thank you!

Thanks for the vertical video series. It was most inspiring and given me food for thought, besides presenting some hard figures. Now on to the job of putting theory into reality. 73'

Tim is series has been excellent, very educational. Thank you.

@timg5tm941

Жыл бұрын

Thank you sir!

I enjoyed and learnt a lot from this episode and the whole series... I'm sad it's come to an end! I hope you continue with similar series which bring so much clarity to the black art of antennas. Thank-you Tim. 73

@timg5tm941

Жыл бұрын

Thank you! I’ve enjoyed doing them!

Watched it 3 times. Brilliant! Thank you

@timg5tm941

Жыл бұрын

Thank you Steve

Thanks for the series Tim n thank god for school holidays as you keep us all busy :) great series and people should look at your back log as well worth a look 👍👍

@timg5tm941

Жыл бұрын

Thank you Andy

Thanks Tim, excellent video - has given me some ideas for optimizing my recently installed HF vertical :)

@timg5tm941

7 күн бұрын

Glad to help!

Great stuff Tim 👏 👍 The chart gives a great visual of lenth/band optimisation when planning an end fed....

@timg5tm941

Жыл бұрын

Thanks!

love the British sayings you inject into the commentary "all swings and roundabouts", "horses for courses", you have an excellent command of the queen's, oops I mean king's English! thanks for the consistent tutorials

@timg5tm941

Жыл бұрын

Thanks Pat!!

Ok, so I setup my new 20m shark stick this afternoon. I elevated it roughly 8-9ft off the ground on a wooden pole and ran 4 1\4 wave radicals that angled down and terminating about a foot off the ground. No idea how it was going to work out, but found swr below 1.5 to 1 across the band (it started to rise sharply at the very end, but didn't get above 2 to 1). Even though everyone was complaining about band conditions, my first contact was from Florida to Bulgaria. Got a Colorado and a California before I had to tear down for a thunderstorm. Noise floor was S3 or so throughout. Went from metal flag stake in the ground to 3ft aluminum pipe to wood mast. When I removed the a!uminum riser in the middle, swr went crazy so I put it back in. Didn't get a chance to see what would happen if I replaced the wood section with another aluminum section, thereby grounding the antenna. I was overall pleasantly surprised, however for it's first time out !

@timg5tm941

Жыл бұрын

Great job 👍👍👏👏

Tim - thank you for all that you do for amateur radio. Your videos are very informative. All the best, Dave K7CI

@timg5tm941

Жыл бұрын

Thank you Dave that’s very kind 73

Your amazing understanding of antennas is sublime - a great explanation of efficiency vs loss for each band. I ended up buying a 43’ commercial vertical. I wish I had seen this video before buying. Well, I guess if the higher HF bands are hot, one could remove sections to achieve a desired length for 20-10m. I’ve bought successive diameters of T6061 aluminum tubing to make several verticals. Experimenting from 23’ to 34’, I found that a 27.3’ vertical, fed by a 1:4 unun to be a great performer 40-10m. Your last gain chart for each band vs antenna length, taking into account loss, should be a screen saver!😂 Brilliant insight, Tim. I’d be honored to talk to you across the pond sometime. Thank you for your great advice on QRZ too! ~73

@timg5tm941

Жыл бұрын

Thank you! Experimenting with antennas is great fun and I’m glad you’re enjoying it. 73

Excellent method of explanation Tim , you remind me so much of our plumbing lecturer at college ,,, That's a compliment 👍

@timg5tm941

Жыл бұрын

Ah thank you! 73

Your videos are very informative!

@timg5tm941

Жыл бұрын

Thank you Andrew!

Great video Tim. Thanks for taking the time to share your investigations. Perhaps I do need to buy the Sotabeams kite one day.

@timg5tm941

Жыл бұрын

I’ll be looking at a 66ft vertical soon with a kite!

What a fantastic video Tim, just wished you lived next door to me!! 👍🏻

@timg5tm941

Жыл бұрын

Hey thanks Peter!

So I just found this video recently and really enjoyed it. For the antenna lengths depicted in the last slide, would those be considered to be end-fed half waves (requiring something like a 49:1 UNUN) or more like end-fed "random" length antennas (needing something like a 9:1 transformer)?

Great video Tim and of course very informative. It must be said of course for new ops or people like me that just want to get on the air, a non perfect vertical will still get you dx when conditions are good regardless of a bit of loss here and there, and my 40m 1/4 wave vertical with A old mfj tuner, no unun, tunes 40 -10m and works dx. I don't use maths too much these days, my equation is small losses vs getting on the air, getting on the air wins every time for me hi. Look forward to your next one tim, and maybe radials vs ground tuning unit. Cheers.

@timg5tm941

Жыл бұрын

Good points Brian!

Great information thank you 👍📻⚛

@timg5tm941

Жыл бұрын

Thank you sir!

As per usual, nice job! food for thought, my 12m spiderbeam pole with some ground radials down by the sea might be rather interesting on especially 20, 17 & 15m. looks like its worth a try for sure! 73, Tom

@timg5tm941

Жыл бұрын

Hmm … could do well near a certain coast!

@TomG2NV

Жыл бұрын

@@timg5tm941 You read my mind mate!

Great video series Tim! If I wanted to run a 12 meter vertical wire for the 20 meter band what would I need to match it? Is there something I can buy or do I have to make it?

@timg5tm941

Жыл бұрын

At that length it’s 0.6 wl long. Impedance is likely to be fairly high but low enough for a 4 or 9:1 unun to do the job. Depending how close you get the tuner to the feedpoint (closer then better)

Great video. Will the receive characteristics versus the quarter wave follow the same patterns?

@timg5tm941

Жыл бұрын

Yes, gain is gain and will be so for RX as well as TX. Thanks for the support 👍 73

I just felt that i needed to add another comment on how educational i found this video. I am at this very moment antenna less and looking to replace my 1/4 wave vertical that i used …. I have wished many times for a table to show distinctly the gain/loss when comparing antenna length v band. Your last table showed me exactly what i have been searching for. At present, looking at a 33’ vertical, but not sure if that is going to be just a tad too long for the neighbours to look at. Decisions, decisions 🤣🤣 … Peter (M0PGW)

@timg5tm941

Жыл бұрын

Thank you very much Peter! Yes I know about the neighbour thing. Maybe use a 10m fibreglass pole but only push up 7m and then extend it by a metre every 2 weeks, by that time they won’t notice! Remember to use more wire each time!

My approach - just stick it up and see if it works. I find tuning out noise is the key to good DX. May get back to some once I resolve some very local QRM.

@timg5tm941

Жыл бұрын

Nice one John!

Very interesting video, full of practical information, thanks. I will assume that all these non-resonant antennas need a 1:4 or 1:9 unun, don't they? I use vertical 1/4 wave wire antennas for 10m and 20m, but I mount them with four elevated, 1/4 wave radials. Feed point is 2.5-4m from the ground. I wonder what kind of difference it makes in terms of efficiency vs. ground-mounted radials.

@timg5tm941

7 күн бұрын

Some might need 4/9:1 yes or a tuner at the feedpoint. Raised radials are a touch better I agree.

Hello, Tim. Thank you for your videos! I have a brief question: what type of transformer (or balun) do I need for 12m. vertical for 17 meters with 16 quarter-wave radials (your setup for this video)?

@timg5tm941

Жыл бұрын

Hi Andrii either a 4:1 or 9:1 depending on the exact impedance presented. As it’s about a 3/4 wl on 17m I’d say a 4:1 unun as a 9:1 might transform the impedance too low?

@andriikolesnyk279

Жыл бұрын

@@timg5tm941 Thanks a lot! Will try this setup somehow. With radials into the salted water.

Hi Tim, I think that there might be a caveat re the first graph showing efficiencies: I believe that radiation resistance should be reckoned at the/a current anti-node in the radiator. I'm not sure whether that principle has been applied in your calculations of efficiencies?

A Verticle is a Verticle is a Verticle! But the 5/8ths (.64) is my go to.😏👍

@timg5tm941

Жыл бұрын

Almost as good as a 3/4 wave!

@andriikolesnyk279

Жыл бұрын

@@timg5tm941 Yes, the 3/4 is the best of them all.

@ericdee6802

Жыл бұрын

@@timg5tm941 Though my experience, "Geographical" makeup yes and no. The only verticles I have are for 10m, I get a little better recieve on a 3/4 but, with the 5/8th I get better DX capabilities.

Hi Tim. Very informative. I have what may be to some a daft question. When you say 16 x 1/4 wave radials, is that a 1/4 wave of the selected vertical height or 16 radials at each band you want to work?

@timg5tm941

Жыл бұрын

In this case it’s 16 1/4 wave radials for each band. I’m reality of course you’d perhaps aim for that many on the lowest band so that it would have even more than 16 on any higher bands!

@CharltonSupporter

Жыл бұрын

@@timg5tm941 Thanks for clarifying that Tim (G4ZRS)

Is than advisable for a fixed installation to use ladder line and a decent tuner

@timg5tm941

Жыл бұрын

It can be done with a vertical. But ladderline is designed for balanced mostly centre fed antennas. Otherwise it risks radiating with common mode and that opens up potentially a range of issues

Tim, I so much enjoy all of your videos! Question: In order to avoid the 2 dB “penalties”, have you done any experiments with vertical dipoles? L. B. Cebik, W4RNL (SK), was a fan, like in his “A Vertical Doublet for 30-10 Meters” article. The elevation patterns and general performance characteristics are very close to the same as traditional verticals with radials. To try to maximize efficiency, following Cebik’s advice, I’ve fed the antennas with ladder line. Given your wonderful experience with various verticals, have you had an opportunity to play with vertical dipoles? Thanks, again, for everything you do for all of us fans of your videos! 73, Eric KB1EHE

@timg5tm941

Жыл бұрын

No problem Eric - email exchange sent 73

Thank you for sharing your knowledge. This is awesome information. Keep it up! 73 BretC/AC0AE

@timg5tm941

Жыл бұрын

Glad it was helpful!

It might be instructive to see the sensitivity to the ground characteristics, versus the 'standard' MMANA setting. And did you try this, can you point to a video where this can be demonstrated? i.e. maybe using RBN to see if the predictions more or less pan out? Models are excellent (and are generally required) but without measurement, it's still speculative. I'm genuinely curious. Good video, thanks.

@timg5tm941

10 ай бұрын

Interesting points - will see about that. 73

What if this theoretical vertical were raised, say... 30 feet in the air, with fewer radials (half as many at most), for 40 through 10 meters?

@timg5tm941

8 ай бұрын

It would work.. but if non resonant you’d need to match it as close to the feedpoint as you can to minimise losses and aim to choke the feedline too as it becomes off centre fed.

So for 10 meter DX a 7 meter wire vertical would be best, but will it give you high SWR? Great Videos.

@timg5tm941

Жыл бұрын

Good question .. within 10:1 for sure .. I’ll check this one out

Very good series. Maybe you could extend it a bit? I may be wrong but I did not catch it if you mentioned the Brewster angle. Or the Pseudo Brewster angle that affects verticals? That may make the 5 degree elevation angle a bit optimistic. Discussions of this appear in many manuals but I call attention to the ON4UN Low Band DXing book 5th edition. ( earlier editions had some mistakes hat were corrected). Even though it is a Low Band book it covers the Pseudo Brewster angle from 1.5 to 30 MHz in figure 9-4. Below the angle the reflected wave subtracts from the direct wave, above the angle it adds and at the angle radiation is down 6 dB from “ perfect ground” patterns. It seems your reference point is the 1/4 wave vertical with 16 radials. The chart equates that to about -9 dB. I am not sure what the 0 dB point is. I have done lots of modeling of verticals and dipoles over the years. The vertical angle is quite significant and Lewallen in his EZNEC manual speaks to the problem of modeling low angle radiation from a vertical. I would like to know what the zero dB point is on your chart. I always like to use dBi as it is a universal reference point that is easy to understand and easy for modeling programs to calculate / use as a reference. I have always found that being broadside to a reasonably high dipole gave significant gain over a single vertical that was not over seawater. The seawater lowers the Brewster angle to near 1 degree over the complete 1.5 to 30 MHz range! It appears nearly impossible to have it at 5 degrees above 3.5 MHz and 10 degrees is even hard to attain where 15 degrees is almost always possible. I typically discount any results below 15 degrees in my modeling. I also model horizontal antennas at that same angle for comparisons. It seems to be a good angle. Maybe you could throw in a dipole for reference and also the elevation angle profile and lobes from the verticals. I know it’s a complicated subject and no antenna covers all directions and angles. We have to compromise a lot with antennas. A great DX antenna may not be worth a hoot at 1000 miles as I have seen first hand! 73 de N4DJ

@timg5tm941

7 күн бұрын

Thank you for these observations - much appreciated. 73

@dandypoint

6 күн бұрын

@@timg5tm941 I just emailed you a link to some good reference books. I have hard copies of several and just found the free electronic version a while back. Nice having them on my iPad!

Tell me iam crazy i have great luck with a 102 inch whip with 4 ground radials course bring a miny tuner with you ive used this going on vacation all of the times i get out great on 20 meters a d 40 meters them 10 meters it works very well ive worked stations from all over i was thinking making a rotatiating dipole out of the as well tell me if iam ok i have to carry a mini tuner with me it gets out you tell me its ok thanks

@timg5tm941

Жыл бұрын

Oh yes a rotating dipole at 1/2 wave above ground level would be nice!

Here is an idea what happens if we take 2 verticals 7m and let's say 12m and connect them like " fan" to the same coax, both using the same set of radials, could we than enjoy both worlds? 10m and 40m with minimum loss? will the antennas just cancel each other and tuning this system could be a nightmare? Just thinking stupid, any ideas? did anyone had a go doing that with a non-resonation antennas?

@timg5tm941

Жыл бұрын

Interesting

Which UNUN ? 49:1 ? for a 70% wave length vertical_

@timg5tm941

4 ай бұрын

Good question. Ay 70% you are close to a 3/4 wave vertical. Impedance is LIKELY to be in the 100-300 ohm range. Try a 4:1 maybe? You can them consider this for multi-band use. For instance, a 7m vertical will be fine for 30-10m and a bit of a compromise for 40m. Lengthen to 7.5m for a good 40-10m solution.

At 00:20 you said “higher rates of resistance “. Is this what you meant to say? (Or at least that’s what it sounded like to me.)

@timg5tm941

Жыл бұрын

I just checked .. it was “radiation resistance” so the higher the better

Wouldn't it be cool to set up a DX Commander with these revised 70% element lengths on each band from 20 m down to 6 m, of course the 20 m would have to come back down because it's so long but all of the others would fit on a 10 m pole.

@timg5tm941

Жыл бұрын

Indeed! Worth a go.

Considering there is about 6dB difference between S-units, you can see how little difference the length of the vertical antenna really makes. Not worth fussing over a change of 1 or 2 dB

@timg5tm941

Жыл бұрын

Oh yes that’s true. Of course, the video was about maximising the performance of a specific type of vertical, in this case a non resonant multi-band single vertical. As I said in the film, even when an antenna on a specific band is -2dB compared with a 1/4 wave version on say 5 degrees, you’ll still make contacts. Maybe not quite as many. 73

Look who bought a new microphone.....

@timg5tm941

Жыл бұрын

You spotted it!! LOL