Local Emergency Communications with NVIS - Let's Build an 80m/40m Dipole

In this video, we'll take a look at building a simple 40m and 80m dipole for $20 dollars. Then, we'll deploy it in an NVIS (Near Vertical Incidence Skywave) configuration for local and regional communications.
If you're new to the channel, welcome! I'm "The Tech Prepper" and I try to produce weekly videos on all topics related to preparedness. Thanks for supporting the channel! If you like the content, don't forget to hit the thumbs up icon, leave a comment, and subscribe to the channel. "Be strong, be safe and be prepared." -- The Tech Prepper
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[@KM4ACK]

NVIS is one of my favorite configurations. 👍

[@TheTechPrepper]

I can see why. It’s a pretty simple, effective configuration. Take it easy, Jason.

[@davidsradioroom9678]

Me, too!

[@wildlandoutdoors51]

KM4ACK any tips on determining wire size for max wattage

[@grampsradio]

HEY! Aren't you supposed to say 73!? Or if'n ya really take a shine to um, 146!?@@TheTechPrepper

[@brooksgreen4910]

4. ❤К🎉ри ​@@TheTechPrepper

[@OH8STN]

Here's a couple of ideas for you. Rather than spreading it out like a dipole with a center mast, put one leg of the dipole between two trees, and fold the other leg of the dipole underneath and in parallel with it, laying on the ground. Also try taking the length of wire the same total length of your dipole, and placing it underneath your dipole on the ground. This is what's known as a passive reflector.

[@TheTechPrepper]

I appreciate the alternate configuration. I think I'll give this a try and see how it performs. Thanks, Julian!

[@Deacon72]

Julian is the man when it comes to portable nvis ops, I've learned so much ( spent alot 😉 ) from watching his videos. While I luv his ops I really enjoy building battery packs!

[@W-733_KWX]

Just something came to my mind: the reflector on the ground, hasn't it got to be 5% longer than the radiating element?

[@MrLahunter29]

@@W-733_KWX yes +5%

[@W-733_KWX]

@@MrLahunter29 thanks for your reply, I wasn't sure

[@1polonium210]

No question about it! The dipole is an easy, inexpensive antenna to build, and it is very reliable. I've built several, and for NVIS, I think the 40-m is ideal. Very good video! 73 KI5KET

[@jameshennessy6143]

Infantry RTO here. Your hasty antennas are spot on. Keep up the good content!

[@TheTechPrepper]

Yes! I'll take it. You might get a kick out of the improvised field comms series I did last year. I built another NVIS antenna out of scavenged wire (coyote electric fence wire and chicken coup mesh) in the back yard, a 2m jungle antenna, and even improvised at 19" 2m vertical for the HT. Thank you for your service.

[@KE0UEO]

Excellent. Very informative.

[@donaldsmith3048]

some good ideas! thank you for the ideas!

[@Mr1MOA]

Great video, going to make a 40 meter dipole this weekend. Very simple design, very doable.

[@MyTube4Utoo]

Very interesting. I'm gonna have to build one. Thanks for the video.

[@timlewellen9041]

NVIS as far as I am told was first stumbled upon by the army in WWII we operators on the Gulf coast have been using it since the 90's for after storm Emcomm work since pretty generally the trees are gone or broken. Also as you have found 4 to 5 foot works great, we are deploying it as a go-kit item for Winlink stations to relay messages from VHF stations in a 25 mile radius to the state EOC in Austin and it makes the hop easily and can be used on low power to conserve battery. You are doing a good job keep up the work de WX5GC ARES district 9 Southeast Texas 73

[@davidsradioroom9678]

You say you are a newbie to amateur radio. You come across as an old timer. Great going! 👍

[@TheTechPrepper]

Thank you for the kind comment. I've only been on the air since March of last year and just recently upgraded to General. Trust me, I struggle continuously in this hobby. It's a fun learning experience and fun sharing the info as it comes. 73

[@davidsradioroom9678]

@@TheTechPrepper You're doing great! Keep up the good work.

[@rlm975]

Great video. Not showy. Not overtechnical. Frugal. Good base knowledge.

[@TheTechPrepper]

Glad you enjoyed it. I had a hard time with NVIS until putting it into practice. There was a follow-up video I made on the same subject not too long. NVIS on 40m/75m/80m has been a game changer. 73's

[@dennistate5953]

Thank you; well done!

[@TheTechPrepper]

Glad it was helpful!

[@randlecarr3257]

Dude this is PERFECT. Thanks!

[@TheTechPrepper]

Glad it helped!

[@neubert500]

You are doing an EXCELLENT job of being an Elmer! GREAT JOB. Thanks for your efforts and Videos.

[@TheTechPrepper]

You’re very kind. Hopefully this little inexpensive build will help other new hams make the jump into antenna builds or at the very least help them get a better idea of using NVIS in practice. Take care!

[@sire24657]

Thanks much for sharing; I need to get into NVIS and more comfortable with HF in every aspect. Greatly appreciated

[@TheTechPrepper]

It's my pleasure. I appreciate the view and comment. HF is a lot of fun and NVIS is amazing. I am considering operating 80m from a valley to really test local communications. 73

[@richardkennedy815]

NVIS has long been a special interest. I had never tried to actually build my own antenna's, and I've been doing this for years. Thank you. Great job.

[@TheTechPrepper]

Glad to hear that you've already been using NVIS with good success. 73's

[@fm71450]

Thank you for all of your videos. My 40 meter dipole was different in that I used a 1:1 balun (somewhat heavier gauge wire, also)=. So much material that I read showed the balun that I thought it was a given. With more research, I found people like the DX commander doing wire antennas WITHOUT a balun. The balun adds weight and cost - whether it has any benefit I will test by doing a side by side comparison. I am new to ham radio, and am learning every time I get on the air. Keep it up!

[@betterbprepared]

Great build and very informative video. You have inspired me to build an 80m as well. Thank you and 73!

[@TheTechPrepper]

Good luck with your build. 40m is great for regional communication during the day. I've been using it daily with my group in the Southwest. Works great.

[@eduardopower5254]

Excelent Job Gastón! A small contribution from me, adding a 1:1 small balun to your dipole will help in not radiation of the coax, a bit less noise as well. Great videos man. 73

[@TheTechPrepper]

Thanks a lot for the contribution, Eduardo. Please keep them coming. Do you know of an inexpensive 1:1 balun build? I have the PackTenna In-Line choke and will start to use it with this build, but it is a bit on the pricey side for people interested in a low cost antenna system. 73, KT1RUN.

[@RadioAdventurer]

Great vid! I use NVIS fan dipol (80-40), works great. 9A3GVD Radio Adventurer.

[@TheTechPrepper]

Thank you! Good to know. The fan dipole or linked dipole seems like the next logical evolution for this build. Thanks for sharing.

[@virgilioleandro]

I really liked this antenna! Very simple, practical and functional

[@TheTechPrepper]

Glad you like it!

[@thewheelchairprepper8070]

FIRST…THANKS FOR MAKING THIS WONDERFUL VIDEO…I HAVE BEEN A HAM SINCE 1978 AS IS MY WONDERFUL WIFE…I TOO AM NOT VERY TECHNICALLY MINDED I LOVE HAM RADIO BUT WE HAVE A VERY COMMON PROBLEM…MANY HAMS MAKE HAM RADIO TO DIFFICULT FOR OTHER HAMS ESPECIALLY NEW HAMS! I AM SO GLAD TO SEE THAT YOU AND OTHER NEW HAMS COMING INTO THIS HOBBY…YOU ALL ARE A BREATH OF FRESH AIR AND VIEW POINTS! YOUR EXPLANATION OF THIS SUBJECT IS EXACTLY WHAT IS SO LACKING…CLEAR AND SIMPLE PERIOD WITH NO BS! SO REFRESHING TO BE SURE…THANK YOU AND I JUST SUBSCRIBE TO YOUR CHANNEL …WELL DONE SIR…I ALSO SEE A FEW FRIENDS THAT ARE HERE KM4ACK JASON IS JUST ONE OF THOSE…I LOVE HIS CHANNEL ALSO…73 AND KEEP UP THE GREAT WORK!

[@anthonymarino4260]

well done

[@Slade677]

Excellent video. I've been a ham for 40 years and have always been interested in NVIS, but never tried it. I'm going to put this together and give it a shot. Thanks for the video!

[@TheTechPrepper]

Thank you! You want to watch my most recent video where I demonstrate NVIS from within a canyon on 5 watts. 73

[@Slade677]

​@@TheTechPrepperI can't find that one. Can you post a link?

[@TheTechPrepper]

@@Slade677 "How to Make a Travel Comms Plan" kzbin.info/www/bejne/g5qrdZmuapyJa80

[@Slade677]

​@@TheTechPrepperThanks. Another excellent video. How do you find specific people to contact via NVIS? Do you belong to some sort of club?

[@TheTechPrepper]

@@Slade677 Great question. These are friends and people in my network.

[@kevingoshe4371]

Nicely done, sir!

[@TheTechPrepper]

Thank you! Still shocked how well this little project turned out.

[@KS6DAY]

Excellent video. Many thanks.

[@TheTechPrepper]

You're welcome. You may like a couple of videos in my No Random Contacts series. There are three with real-world NVIS examples. 73 de KT1RUN

[@Cr0cket20]

Just got my general and spent the first week on air using a 40M and 20M antenna following your video instructions. I've been very interested in the NVIS configuration and both antennas have worked great. I've actually been surprised at how far I can get out given how close to the ground the antenna is. Greatly appreciate the info.

[@darrinpearce9780]

Great video. Constantly get 300-900+ km on 40m running JS8Call 10watts with 40m dipole 5 feet above the ground. NVIS rocks.

[@TheTechPrepper]

Wow, that is so cool. Thanks for contributing to the discussion and helping demystify NVIS with your experience. It’s very helpful to know that your setup works at 5’ as well.

[@darylsawdy3910]

Enjoyed this video alot! New General myself and I am trying to build this antenna myself. Thanks! From Milan Tennessee.... formerly of Payson, Arizona 🙂

[@TheTechPrepper]

Cheers from Arizona!

[@thequarantinecatholic]

I like that you do not use 3D printer - great video!!!!!!!!!

[@TheTechPrepper]

Use what you have. ;-)

[@Marty48034]

This is a great start. Thank you for the info. Time to get my General.

[@TheTechPrepper]

You're welcome. Good luck with your upgrade. Here's are more recent NVIS video that was a bit more real world: Offgrid Regional Communication - No Random Contacts Series kzbin.info/www/bejne/r6GwfmOpeLp5kK8

[@Marty48034]

@@TheTechPrepper Good stuff again. Thank you. Taking notes. (Radios are spendy, but the antenna apparently doesn't need to be.)

[@markwhittington5020]

Thanks, I have been researching this subject myself, and your overview is the most helpful overview I have found. Your right, the information out there on NVIS is overly complicated. It is great to see a common sense explanation with a real world example.

[@TheTechPrepper]

It's amazing how overly complicated the literature is on NVIS and potentially off putting for myself and other hams. I am glad you found this video useful. This channel is all about practical preparedness and real-world testing. I appreciate you taking the time comment. I hope you stick around.

[@Widderic]

Man this is so cool! It's daunting though!

[@keithsafford3056]

Great job Tech Prepper! I have been using VHF for a while and just bought my Xiegu G90 and am looking at a number of antennas. I bought a couple, but want to make one on my own and learn abut antenna theory. This antenna is on my "Gotta To Do" list. Again, awesome job.

[@TheTechPrepper]

Excellent attitude. A simple build like this is a great way to experiment and get a little antenna theory under your belt.

[@binder098]

Good job.

[@TheTechPrepper]

Thanks. You may also like this newer video where I demo 80m NVIS using the same system. The other stations were running a kilowatt and I was running 6 watts on the FT-818ND. kzbin.info/www/bejne/Y6GufY15qryNj5Y

[@hangonitsgettinreal]

Thank you Gaston! It was because of your videos that I decided to upgrade to General. 73

[@TheTechPrepper]

Congratulations! General is the sweet spot of licensing. 73

[@geizhals0815]

very impressive demonstration!

[@TheTechPrepper]

Thank you! Cheers!

[@adilaui3293]

I enjoyed watching your videos, this one was spread through the club members here in Morocco as we conducted our 1st time ever EmComm drill. 73 from Africa

[@TheTechPrepper]

Thank you and hello form the US. How did your exercise go? You may enjoy last weekend's NVIS test. This one was targeted and planned for a very specific comms window: kzbin.info/www/bejne/r6GwfmOpeLp5kK8 Have a good one.

[@adilaui3293]

@@TheTechPrepper hey there, I have seen that one too, Our exercise was the first time ever, and we did it in closed network since the legislation is not there yet to allow cross comms with authorities. The video is in french, but you'll get it for sure. kzbin.info/www/bejne/hoOniKVsnstgqZo Looking forward to try the EmComm tools (December I guess). Have a good one . 73

[@TheTechPrepper]

@@adilaui3293 Glad to see that your exercise was successful. I understood a couple of words...VHF, for example. EmComm Tools is very much delayed as I have had not time to work on it for several months now. I hope to have it out next year.

[@adilaui3293]

@@TheTechPrepper I appreciate your engagement and the information explained in a very simple and clear way. Looking forward to hear about the EmComm tools next year. Sorry for the french in the video, it is our first foreign language, I guess it was better understood than Arabic version. Take care and be strong, be safe and prepared.

[@dandypoint]

I have had great success just past the ground wave distance on 40 with very low dipoles. I will note that wires in very close proximity to the ground have a lower velocity than antennas at more normal heights and therefore the resonant frequency will be lower quite a bit. I once had an 80 meter inverted V and could change the resonant frequency from the SSB to CW band by lowering the ends! I also take advantage of this with my Beverage receiving antennas by putting them directly on the ground. 73 de N4DJ

[@brian.7966]

love it just love it well done.

[@TheTechPrepper]

Thanks. You may enjoy a recent follow-up video I did with another NVIS antenna on 75m. Glad you enjoyed it.

[@possumpopper89]

I am trying to learn about ham radio. You helped make the building of an antenna more easily understood. I just bought the ARRL book to study and plan to test in the next month or so. For me this is a dual learning curve, learning the jargon as well as learning the technical aspects.

[@TheTechPrepper]

I like your style. I am a big fan of approaching amateur radio the way your taking it on. Keep up the good work and good luck with your license.

[@tjman4943]

Extremely cool video, thanks!

[@TheTechPrepper]

This was my "aha" moment. NVIS finally clicked. It's time for an update video. Glad you enjoyed this older video.

[@tjman4943]

@@TheTechPrepper I did enjoy it, and have been watching all I can about antennas. It seems there's as.much to learn there as there is about the radios themselves. And budget friendly options keep me a float in this game

[@joeyperez8581]

Outstanding

[@TheTechPrepper]

Thank you. I activated a summit with this antenna not long after I made this video. There was quite the pile up. There was a video on that trip. Radio fun starts about mid way into the video: kzbin.info/www/bejne/hmfYoKqBjNmKmLs

[@BargainBasementHamRadio]

Well done! You could also put the 40m and 80m antenna wire on the same BNC-Banana plug as in an inverted V configuration, it would look look like an inverted X though.But you would have both bands ready for NVIS. 73!

[@TheTechPrepper]

Thank you. Great tip. I’m actually planning on modifying the 80m version with a link so that I can cover the voice and digital portions of the band. 80m is wide band. 73

[@MarcMcClure]

Good demo!

[@TheTechPrepper]

Thank you. You have a fantastic beard.

[@maple1600]

Great video!

[@TheTechPrepper]

Glad you enjoyed it. It may time for an update video. I have learned so much more about NVIS since this was made.

[@Cardassiaprime]

Great video, worked well, them bnc/post adapters are excellent for easy dipole centres. I built mine with one from Claude’s VE2DPE Design using 300ohm ladder line, linear loaded by shorting each end, reducing the total length by 33% , 44ft instead of 66ft. Mounted in a flat horizontal config. Worked very well at about 8ft above the ground. 73 de M7PBX.

[@TheTechPrepper]

I need to try this design. I like the idea of being able to deploy it in a smaller space if needed. Thanks for sharing this design. 73

[@thed8229]

Nice. Just ordered those binding posts so I can play too. Kansas eludes me on my WAS. Gonna give this a go. Thanks.

[@TheTechPrepper]

Enjoy the experiment. While not NVIS, I just made a version for 17m. I'm hoping to try SSB for the first time on a WARC band.

[@thed8229]

@@TheTechPrepper I like those blocks. Lots of options to be had with those. I love options. One of these dipoles (just bring precut band lengths) along with my Atas 25 ups my portable game. Worthwhile vid bud.

[@TheTechPrepper]

The ATAS-25 was my first antenna. I didn't think anyone else had one.

[@douglasvamateurradioandmore]

Keep up the work. You’re a bit further in licensing than I. Keep learning and being curious.

[@TheTechPrepper]

You as well. Best of luck with your ham journey. This comment was timely as I have been reading the "AM 1" manual for MARS (January 2021). It has perhaps the best overview of NVIS. A google search turn this up.

[@cwqrpportable]

I really enjoy all your videos Gaston, but particularly this one involving NVIS communication. Thanks for the work and dedication to making these videos, you do a superb job and your presentation style is brilliant. Videos like this encourage amateurs and bring out their resourcefullness. I subscribed today and gave the ol' thumbs up. If you ever find that the legs of the NVIS dipole sag a little on bands like 80m, you can always use some 5-6' wooden stakes with a small notch cut out on the tops of each of these stakes. Pound them into the ground a foot or so and lay the legs of the nvis dipole into the notch cut out on the top of each stake. The stakes can be placed every 20' +/- down the length of each leg and then guy the ends of the two antenna legs with some light cord and a small stake pounded into the ground (a form of guying I guess). I typically use fishing barrel swivels tied to the ends of each leg and then use the interlocking snap on these swivels to attach to some light line like fishing line tied to the stakes. More videos like this concerning your experiences with NVIS would be cool! 73, Brent

[@TheTechPrepper]

Thanks for sharing your tips. Well, you may enjoy this NVIS video. It is part of my No Random Contacts series: kzbin.info/www/bejne/r6GwfmOpeLp5kK8

[@paulhastings3109]

NVIS works great. If you run another wire 1/8 wave below it more grain straight up

[@TheTechPrepper]

I've heard this several times. Is there away to measure the performance improvement with any tools? Or is it a matter have just benchmarking both configurations via signal reports from other stations?

[@joejoslyn9745]

great video!

[@TheTechPrepper]

Glad you enjoyed it. My group and I are utilizing NVIS deployments daily across the Southwest daily.

[@riazahmed7200]

Thanks.........

[@TheTechPrepper]

You're welcome!

[@timshotwell2806]

You are crazzzzzzy, But you are my kind of crazzzzzzy... Good Job..

[@TheTechPrepper]

I'll take it. This video needs an update. I have learned a lot more about NVIS in practice since this came out. I am using it daily for regional communication at home, in the vehicle and while man-portable. Thank you for the comment and view!

[@rkaag99]

Here's a 'cheap-ham' tip. Next time you use a fairly wide zip tie, save the cut-off for wire insulators. Very strong. Drill 'em out the same way you did the Cascade Pod plastic.

[@TheTechPrepper]

Fantastic tip. That would have been easier and stronger. Thanks.

[@gearlab734]

Clever, well done.

[@TheTechPrepper]

Thanks! Still using this little build with good results.

[@gearlab734]

@@TheTechPrepper Yes, I'm thinking of getting an NVIS antenna up myself. I think in a crisis situation, NVIS coverage would be the most useful and local UHF etc too.

[@TheTechPrepper]

I would add to 2m SSB to the list. It's a very effective mode.

[@gearlab734]

@@TheTechPrepper I see, thanks for the tip.

[@andrewfisher1051]

A 3D printer would be awesome to have, but there is nothing wrong with recycling something like the Cascade lid. Cool video.

[@TheTechPrepper]

Actually, a good friend with a 3D printer would be better. Glad you enjoyed the video. I hope you stick around. I’m filming a new video right now on the PackTenna Linked Dipole. It’s going out on its maiden voyage tomorrow during a SOTA activation. 73

[@HamRadioOutlet]

Great video! Love the mouse pad! :-)

[@TheTechPrepper]

I figured you would. ;-)

[@paulhastings3109]

With things being what they are. Wire for 40 and 80 is great. Just off the ground and not getting 6 to 7 feet. Out in the swamp it's great 👍

[@TheTechPrepper]

Paul, thanks for sharing and contributing. Everyone seems to be chiming in with their NVIS success stories. Keep them coming! It's great that you're having luck too at these lower deployments.

[@LouDiMattia]

Great video, thanks! 73

[@TheTechPrepper]

It’s my pleasure. Thanks for the view! 73, KT1RUN

[@aaronsmith22]

Great video brother! Love the channel! W6AEF!

[@TheTechPrepper]

Thanks, Aaron. It’s fun sharing the journey. I’m blessed to have a great group of viewers like yourself.

[@stewartrv]

You might want to have a search in YT for Speaker wire antenna, quite similar to your configuration without even needing the coax!

[@beemcbike]

Nvis is my way to communicate from valley tp valley here in the mountains of Switzerland 👍 Recycling is the better way than 3 d printing 👍🇨🇭 Great. Video thanks and 73 de HB3XBL 👍🇨🇭

[@TheTechPrepper]

Glad you enjoyed it and hello from the USA! I actually work for a Swiss company. You guys make excellent employers and have the right attitude around work-life balance. It's great being able to build simple antennas with recycled materials. 73 de KT1RUN

[@andyM7XTT]

New subscriber,great video thankyou

[@TheTechPrepper]

Welcome to the channel. Good timing. I'm planning on doing another video on the 80m dipole, but this time to have more targeted communications with a known group of people in my home state. This video was mostly random contacts. Enjoy the content.

[@RelentlessHomesteading]

Loved it. I've been too busy with other items to get an antenna going for an HF rig I was given. All the options were too time consuming and/or expensive. Decided recently to just get something simple up. Looking at going the octopus hamstick route - pretty cheap. But not really NVIS. But having both would be cheap and cover the necessary emergency basis I am looking for. I'm like you - I JUST NEED IT TO WORK. I'm not looking for bragging rights - but about acquiring desired capabilities for an undesired future need. RH

[@TheTechPrepper]

You're my kind of ham. Do the best with what you have. Good luck with your setup. I recently did an update video on this topic. And, it is still working great. 73

[@RelentlessHomesteading]

@@TheTechPrepper Yes - Wish you were my neighbor ! My wife and I have a saying around here: "It is what it is" -- ...implying -- so what are you going to do about it? This usually means leaving the perfect solutions to others, and just getting on getting on - in doing what we can with our available time and resources. Our highest goals are always with spiritual preparation, ...but too many forget that "presuming upon God" for their safety and well being is also a sin. We are to pray like God will do it all, then work as if its all up to us. God gives us the ability, talents and resources - if we choose to squander those, then He may not be as anxious to deliver us in time of need. RH

[@W8MJL]

I've been getting ready to put one of these together for a while and now that the snow is gone i can get out more to play with this stuff. Glad to see someone putting it into action and getting good results. 73 de W8MJL

[@TheTechPrepper]

That’s great, Michael. It’s a nice solderless build. It is still serving me well. I use it daily to check my Winlink email and have taken it out successfully on a SOTA activation. I’m bringing it out today for another SOTA activation on 40m. If you do the build, I would be I interested in your experience. It’s great for go-kits.

[@W8MJL]

@@TheTechPrepper I'll let you know for sure. I'm building a last ditch emcomms kit based around my X5105 and this antenna will go great in it.

[@TheTechPrepper]

It’s perfect for a go-kit. Good luck. How do you like the Xiegu X5150? I’m considering the G90 and X5150 for a go-kit.

[@W8MJL]

@@TheTechPrepper I love it, it's a great piece of kit. I've been eyeing them since they first came out and finally pulled the trigger on one last month. Thing that got me was it addition of the antenna tuner and analyzer, that and it didn't break the bank. I was going to get the G90 but i felt the screen was too small for my older eyes, but i know several operators that swear by them.

[@malenve6vid]

Great stuff. A lot of theories regarding NVIS that are iffy if you ask me. If it works, go for it. NVIS is suitable for portable / SOTA. Just a thought, it would be very easy to make it linked as well.

[@TheTechPrepper]

Thanks, Malen. On thing I learned is not to get hung up on theory. Even if your antenna is in a less than ideal area/configuration, try it. If it works well enough, use it. The next iteration will be linked to support 80m/75m. I want to run digital and SSB voice on the same deployment. I am thinking about also making it a fan dipole at the same time to cover 40m.

[@DougNetherton]

I remember another NVIS item that putting a reflector wire directly under the NVIS antenna enhanced the vertical component of the antenna signal like a yagi. You might need your driven element to be further off the ground to be more effective though. Doug, VE3MCF, AK4HB

[@TheTechPrepper]

Thanks for the comment. I've tried adding a reflector wire that is 5% longer underneath for all versions of this NVIS antenna (40m, 75m, 80m) and I have personally noticed no difference. The receive signal reports are about the same. It tested this with WSPR.

[@DougNetherton]

@@TheTechPrepper I suspect you need to have your driven element to be high enough that the reflected signal gets added to the driven elements signal in phase for this to work. Maybe just adding a reflecting element underneath a dx antenna world convert it to an NVIS. Easier than lowering the DX antenna to become an NVIS? Doug, VE3MCF, AK4HB

[@RuckProductions35]

Love the visualization with the water, those types of examples help knuckle draggers like me 😂

[@TheTechPrepper]

You're welcome. I'm a knuckle dragger, too. It clicked after I started thinking of HF propagation in simpler terms. Happy Holidays.

[@charlesrogers7275]

Thanks for this posting of this relevant ARES/EMCOMM topic. Based on my modeling using the EZNEC Antenna Modeling software of the original antenna design by Dr. Carl Jelinek, N6VNG (SK), the following info may be beneficial: Using his original mast height of 15', an 80M antenna leg length of 38', with the antenna end heights of 2.33', and a 40M antenna leg length of 25' with the antenna end heights of 6.67', the results for 80M shows an antenna gain of -3.29dBi. For 40M it shows an antenna gain of +1.25 dBi. There is a resonant frequency at 5.8 MHz with an SWR of 1.16. Making modifications only for the resonant frequencies used for EMCOMM in my state of 3.9MHz for 80M (57.5' leg length) and 7.2MHz for 40M (30.75' leg length), and not changing any of the center or end heights, there was a slight increase in 80M gain to -2.01 dBi and in 40M to 2.57 dBi. Making additional modifications using the same resonant frequencies with the 80M leg length still at 57.5' but raising the center mast height to 30' and changing the heights at the ends of the antenna to 12.33' above ground, the gain is now 3.15 dBi. A greater than 6dBi increase from the original. With the 40M center also at 30', the leg lengths have now changed to 29.25', and the end heights have now changed to 16.67' above ground, the results shows a gain at 5.65 dBi. A 4.4 dBi increase from the original. In summary, even with the low signal-to-noise ratio exhibited by a received NVIS signal, improving the gain can allow the antenna to radiate more in the vertical direction. Charles NM5CR

[@TheTechPrepper]

Charles, thanks for the brilliant overview along with your modifications. I like your design quite a bit. What’s your preferred wire and mast for your version of the build?

[@charlesrogers7275]

@@TheTechPrepper The antenna wire that I prefer is the Davis RF Flexweave in 14 gauge. The EZNEC calculations are based upon this wire size. My mast for 30' is a fiberglass military surplus and for 15' I use 1.5" PVC. Your comments are greatly appreciated.

[@MrTalaue]

Best antenna height for high angle propagation is an antenna height of 0.15 to 0.25 wave length.

[@ChrisBullock1978]

I also know that NVIS can do long distances if you mount the antenna about 10 feet off the ground

[@00Widget]

Your intro got a subscription from me . Lol and I’m interested in nvis antennas ..

[@TheTechPrepper]

Welcome aboard! Check out this video in that case: kzbin.info/www/bejne/r6GwfmOpeLp5kK8

[@GreatRockRealEstateDenver]

Great video, thanks for sharing this technology. Clever demonstration with the hose. Can you also share a link to the soft case you used to package it up for portable use, please?

[@nPcDrone]

Adding this to my survival set up. Gotta upgrade my license to get on the HF

[@TheTechPrepper]

Good luck with your upgrade. You'll never regret the effort studying. I've used many antennas, but boy does this work remarkably well. It's a keeper in the kit and easy to repair in the field. Next month I'm starting an HF NVIS mini series for target contacts. Here's a video with that same antenna running 4' off the ground. It's somewhere near the middle: kzbin.info/www/bejne/hmfYoKqBjNmKmLs

[@nPcDrone]

@The Tech Prepper so much to learn. Prepping is more than a water filter a rifle and 5 gallon buckets of rice

[@tomperone9338]

We deploy NVIS antennas quite frequently in our State Guard, as we're not really interested in communicating much beyond 300 - 400km or so. It's a remarkedly effective technique.

[@TheTechPrepper]

Excellent! It always amazes me how effective this technique is in practice.

[@georgeriedel9357]

Good Vid son, I echo OH8STN, Julian, place a REFLECTOR Wire directly under the xmitting wire as a reflector, works great

[@TheTechPrepper]

Thanks for echoing the suggestion. I think I’ll try this today. That little antenna has been working great for the past few months, but it will be nice to see if adding the reflector wire will help. 73

[@greghovland9227]

@@TheTechPrepper Did you attempt the reflector? If so, did you notice a significant change?

[@briantheminer]

Put round terminal connectors on the wire, saves the post trying to crush and cut through the wire Loved your video

[@TheTechPrepper]

I've been doing this on all new antenna builds for the last year. I actually found some terminal rings that have heat shrink on the connector. I think they first started appearing in my Improvised Comms series. Great recommendation.

[@briantheminer]

@@TheTechPrepperI didn’t realise video was 3 years old ! Wow

[@TheTechPrepper]

@@briantheminer Yep. I've been sharing the journey along the away. If you're up early, I am doing live stream for our 50K subscriber giveaway. Cheers!

[@phatforrest]

These simple antennas work absolutely great. They're cheap, portable, and lightweight. Get a few BNC binding post adapters (cobra heads) to keep with your gear. If you're going to buy one, might as well get a few. Grab some wd-1/tt field wire for antenna wire. For around $100 bucks, you'll have a kilometer of wire that's got a tough jacket, copper and steel strands for appx 200 pounds of tensile strength, and is easily soldered. Don't forget about 60 meters either, it's a great band that has some of the best characteristics of both 40m and 80m, and there's usually not a lot of chatter on it either.

[@TheTechPrepper]

Thanks for taking the time to comment. I never heard of wd-1/tt field wire. It seems very popular with military’s around the world. After a quick search, I found some Swiss surplus field communications wire. What a great deal-$45 for 656’. This really drops the price for this simple build. I’ll give 60m a shot. At these prices, I can have a dipole for every band. Although, I’m experimenting with manual links.

[@Inkling777]

Fair Radio Sales in the U.S. has various types of military field wire in different lengths. They're also an excellent source of military surplus electronics.

[@tunnelrabbit2625]

More Hams need to know this stuff. I attempted to get my local friends interested starting 10 years ago, but they had no time for it. Even as survivalists, they are still not interested. Younger guys will have to lead the way, and there are precious few young guys who are serious about survival comms. NVIS propagation will be essential if repeaters go down. If using terrain advantageously, DFing is nearly impossible. And that is a fact few are aware of, or appreciate in this day and age. If using 160 meters, there are other advantages as well. They may have to learn the hard way. Be ready to reintroduce short skip propogation once the time is right. For now, most Hams will stick with the narrow bandwidth and ideas that define amateur radio.

[@TheTechPrepper]

Yes, HF and NVIS is critical for real grid down comms. This video is a bit dated, so there will be an HF mini series specific to using NVIS for targeted comms. This series will start next month once the manpack series is complete. I'll even touch on this topic at a high-level in the manpack series once I get to the first set of a HF-capable manpacks. Cheers!

[@johnwest7993]

Add small metal disks to the ends of your antenna to broadband the antenna.

[@jeffsecules184]

Like some 1” washers? Can someone explain and verify this? I would like to make my dipole more broadband if I could.

[@Brandon-dg8zn]

Though the antenna is an important part of the overall NVIS configuration, you have to be able to pick the right frequency. There are resources out there for this, especially for NVIS. Remember, NVIS comms rely on the signal being reflected back down at very acute angles. Choose the wrong frequency and the signals will go straight through the ionosphere and not be reflected back. This is why you see most military HF rigs only go up to 60mhz (or so).

[@daveN2MXX]

7:30 nice wire stripper which doesn't damage strands of wire, as opposed to the pos used on some other youtube channels!

[@TheTechPrepper]

Thanks. I believe in having the right tools and I think I payed $25 to $30 for this and use it on every project where wire stripping is involved. Thanks for pointing this out.

[@chrisscott1547]

Your efficiency will rise at somewhat greater heights, up to about 1/8 wavelength. If you also run a slightly longer wire on the ground under the dipole, you can lessen your nominally -3 dB loss heating soil. Note that your swr bandwidth will be less leading you to believe it's not doing as well - but that's only because the resistive soil isn't swamping out the antenna impedance as much.

[@TheTechPrepper]

I've read up more on the literature since this video was made. Army MARS has a great introduction into deploying a NVIS dipole and your suggestions are very similarly to their recommendations. I appreciate you sharing your tips with myself and the community. I'm working on getting some permanent masts to give myself quite a bit more height. 73

[@WadeAbout]

Super light coax say rg174 is fine for those freqs and would fit in that kit

[@TheTechPrepper]

You're 100% right. I typically run RG316 for HF in my field kits.

[@jimcoulter5877]

Yup, we can tell you are in Southern Arizona by the Plants behind you!

[@TheTechPrepper]

Dang plants giving away my location. 🤣

[@grampsradio]

You’re silly but I like you anyway. That’s why I subscribed. 11:35 and here is where the Tech Prepper got himself into trouble!

[@TheTechPrepper]

I wish I had something funny to say. I have nothing. Welcome to the channel!

[@jeremytanzer279]

Good stuff! I'm supposed to be giving a talk on NVIS to my ARES group. Like you, I'm fairly new, but I think NVIS is a great method.

[@TheTechPrepper]

Another new ham... fantastic! Try this little build out. Try 40m in the mid to late afternoon and 80m at night. Good luck with your talk.

[@M7BCN]

Excellent Job. I’ve got 10m, 20m and 40m working well but missing a capable antenna for 80m. That’s about to change now. Thanks and keep up the good work. M7BCN

[@TheTechPrepper]

Thank you. It’s not the best antenna, but works well enough especially for the price. I re-trimmed the 80m version for the digital portion of the band. Works great for getting into a local Winlink gateway. Good luck with your build. 73!

[@M7BCN]

@@TheTechPrepper Made an 80m Dipole that’s sitting just below the top of my 6ft fence. It bends around my garden and I’m blown away at how well this thing works.

[@TheTechPrepper]

​@@M7BCN I receieved alot of email from more experienced hams indicating that this would not work. Glad to hear it's working.

[@M7BCN]

@@TheTechPrepper I’ve uploaded a video of my first contact using it. kzbin.info/www/bejne/oJnLdJ-ZnKmegJY Thanks again. 73.

[@TheTechPrepper]

Thanks for sharing your QSO, Brian. Looks like it works nicely. Great signal report. 73, KT1RUN

[@cdevidal]

Another advantage of NVIS is it makes it harder to triangulate. Signal is coming from the sky.

[@TheTechPrepper]

Correct. The signal looks like it's coming for everywhere.

[@WJ6FRadio]

Outstanding video! I enjoy using NVIS, and used to discuss it quite a bit on the website I used to own (Doomsday Prepper Forums.com).

[@TheTechPrepper]

Thank you. Interesting. Are there any good resources that you would recommend for NVIS? Any other antenna options?

[@kc7js]

If I seen you your video sometime ago I would have already shared my experience with nvis. Several years ago I was estate director for navy-marine Corps Mars living in North Dakota. It had been snowing for sometime and I needed to call the net SD/ND. My g5rv antenna spell the ground it was lying on top of the snow(6"). What the heck! I called and it anyway. To my surprise Communications? FINE! I hope it worked as well for you Jack KC7JS/NNN0ZBE

[@TheNoCodeTech]

#ThNHR #TeamReplay for the win!

[@TheTechPrepper]

What would we do without #TeamReplay?

[@jamescookad9bu]

I'm new to building antenna do you trim off the excess legs or do you just keep them wrapped around?

[@BrantleySmithNC]

I'm really enjoying your channel! I'm a new ham as well and working towards my General license now. If one were to setup a properly-tuned end fed half wave antenna in a horizontal configuration do you think you'd get similar results?

[@TheTechPrepper]

It’s always nice to meet a new ham. I’m very new to NVIS and have not tried deploying an EFHW in this configuration. I’ll try my PackTenna Mini 20m EFHW soon and see how it performs. I have a feeling it will work. Good luck with your General upgrade. You won’t regret it. 73

[@johnwest7993]

A very amusing analogy. I don't know that weak-signal digital modes aren't making those contacts using other atmospheric modes than NVIS. SSB contacts at 60 to 200 miles make it clear it's NVIS communications.

[@DeltaWhiskeyBravo13579]

Good performance on a $15 dipole. Can't argue with the results. 73 de K9DWB

[@TheTechPrepper]

It’s surprising how well it works. I made my first Winlink connection with ARDOP on 40m over the weekend and have been able to successfully check for messages the last two mornings. I was talking to a fellow on SSB yesterday and he made the point that the antenna would not work and that I have to move it to 30 feet. At any rate, I’m happy with my little $15 antenna. Thanks for the comment. 73

[@chetpierce1507]

Brand new Ham here. Love the videos. I am focusing on NVIS as my first set up unfolds. I have a question regarding mobility of the system. Will it remain functional to mount this type of antenna on a loom type rack, maybe 4 or six inches between each pass of the wire and mount it on the roof of a car or truck? My thoughts are to remain truly mobile with the system.

[@TheTechPrepper]

Welcome to the channel, new ham. Good timing as I am experimenting with this same setup again, but on 80m. I'm not sure about your experiment, but try it! I have also played with this setup for a mobile deployment while stationary. If you have a receiver hitch on your vehicle, get yourself a flag pole mount that fits in the receiver. I also found 16-24' painter's poles to work great when dropped into the flag pole mount. If you check out my Instagram feed you can see some of my NVIS work that's in flight now. I will do a video soon on this topic.

[@beauxgaloo9621]

That’s a slick ass move ass move

[@TheTechPrepper]

Thanks ;-)

[@gambon4220]

Hi, I was looking into how the banana connector works and from what I see one side is the wire in the coax cable, and the other side is the ground. Why do we connect a wire/antenna on the ground side? Does it also contribute to the signal? What would be the difference between that and only connecting a wire on one side, not on the ground?