Hey, Jason. The antenna you have will work, and it will work well. You just need to tweak your methods a bit. First, you have to be familiar with Maximum Usable Frequency (MUF). At our current point in the Solar Cycle, 80M is generally better than 40M during the day. Here's a great propagation prediction website: www.voacap.com/hf/ Move the cursors: one to your location, the other somewhere within 50-100miles away. Set the antenna heights for both stations to 17ft dipoles on 40,60,80M. Choose your mode and power. Click on the Prop Wheels to get an excellent graphic of the percentage of success between the two points around the clock. It's not a perfect match, but it'll get you on the right track. For NVIS reading: www.universal-radio.com/catalog/books/5444.html This book is a compilation of articles LTC Fiedler and others wrote for the military. It is an excellent resource. Also: Army Field Manual FM 24-18. Read Appendix M: Near Vertical Incidence Skywave Concept. Ocean County ARES in New Jersey has used an antenna design similar to yours to communicate all around our region -- from 15mi out to 308mi (and all over in between) using SSB and various Digital modes. When you play with the VOACAP page compare 100W SSB to 5W CW/Digital with all other settings the same. You'll see why Digital is far more efficient for EmComm than SSB -- but I guess that's no surprise. As for vertical whip antennas. Again, you have to look to the military. I'm sure you've seen whips tied down over jeeps and Humvees. That's not to get under bridges. It's to raise their take off angle from low to nearly vertical. Now if you read their manuals you'll find that while that works, it is a compromise. The whip radiates best when bent off the BACK of the vehicle. However, it's not practical to drive with a 16ft whip sticking out the back, so they bend it over the front when moving and off the back when stationary. I've experimented with bending a 75M Hamstick on a spring off the back of my truck. It's a huge compromise, but it does work. I've gotten ~75mi away with 30W SSB. So anyway, I hope this helps you on your NVIS quest. Like I said earlier, you're well on your way with your wire antenna. Check my QRZ page for more info on the OCARES ANA-1 NVIS wire antenna that Ocean County ARES uses. It's cheap and easy to make, light weight, super portable, easy to deploy and tear down, can be used on 40/60/80M and....It works! This is not to say that you can't add reflectors or raise the height or slope it or whatever else to get some better performance out of it -- or better yet just get an endfed inverted V or an AS2259 dipole. But for our portable needs in ARES, it works great as is. Good antennas don't always have to be complicated. Best of luck, 73 NJ2N

Thanks to your video I was motivated to experiment with my Little Tarheel 2 during the recent OH ARES NVIS Day. Using a modified quick disconnect to SO239 connector and ran 50ft of coax out at 10ft in the air. (The coax cable is what I normally carry in my go kit, 10 ft up using the mast sections and mounts I normally carry, plus cargo straps and a handy tree). Had good results on 80M copying the state EMA at 40+ and they received me at 57. It would not tune at 40, I think the coax was too long as the Tarheel only came up as far as it normally does at 20M. Didn't think to check tuning on 160. Need to check that next time, along with experimenting with shorter coax runs to get it tune up on 40M. Thanks again for the idea! 73 Randy KAØAZS

Tennessee here also (W4TJP) 🙂 Keep on doing the work. Enjoy your content.

Great vid. Answered a few simple questions I’ve had for awhile, and found few answers. 73’s y’all

Nice video. Thanks for taking the time to test it. With the new band hopping scheme on wsjtx, there is an order that is no longer random to optimize when stations are listening and transmitting to maximize the number of stations on a band at a time. It may have been that some stations in your area weren't on 40 when you were TX. Adding a ground screen of horizontal elements will help in general because of the amount of loss of signal into the ground. What most antenna modelling doesn't show is the radiation pattern into the ground. In Ground Penetrating Radar, GPR, we use that energy, which is significant. Thanks again Brandon W0GPR

I was planning something similar with an FT-857D in my pickup truck. The plan was a 3/8" mount on the edge of the pickup bed where I count mount an MFJ HamStick for DX or an end fed dipole with an impedance matching box for NVIS. I'm due for a new truck so I postponed that installation. Thanks for the WSPR testing.

Great stuff!!

Portable vertical antenna still works NVIS, but a horizontal wire off your feed point, I have a icom AH4 tuner installed on the truck

I guess the key measure of success is to determine if you've eliminated the skip zone.

Interesting results ? Good comments on here also from other viewers. Thanks for putting this together Jason. 73 de 2E0IEH

Nice test. Thanks. I use a 96" whip on a Chameleon base. When I want to go NVIS I bend the whip over my roof and tie it to my luggage rack. It works quite well. 73, Charlie - K0CKH

I use your EFHW kit parallel to the ground about 6.5’ above the ground and can communicate across the the State of Hawaii with 6W. The closer stations about four miles away on Oahu works fine, albeit a bit weaker than the stations in Hilo on the Big Island. An HF Kit EFHW set in an inverted Vee is both an excellent NVIS as well as DX to South Africa 12K away.

That was my go to antenna for my vehicle. Ground reflector was also incorporated. I'm local to you, will have try making contact.

That airplane was flying in a circle because he left his blinker on lol! :) Fun vid!

Maybe someone has already mentioned it, but foF2 was 4.65 MHz at the time of the video according to the nearest Lowell Digisonde I found (looking at an ionogram), which means the 40m band would not have worked for high-incidence skip-zone-free comms. 80m would have worked great, right at the sweet spot, there was even a double hop trace above it in the 80m portion of the band. Nice setup though!

I love your bloopers. VA2SOB - 73.

Good stuff Jason , would definitely be interesting to see what a large whip antenna would do like a 102". Glad you were able to get past the airplane attack !!

I suspect WSPR is so sensitive that your results are skewed indicating they are similar. I agree that SSB voice would result in a more significant difference.

Sure you can build a towel bar antenna and it will work too

Great and informative video Jason. Have you tried to lay another wire on the ground below the antenna wire, like a reflector? I have heard this gives it more of a "cloud warmer" type of take off angle.

Hi Jason. In wspr you can add delimiters such as VK1MIC/A and VK1MIC/B etc. saves having to wait.

Interesting results. Not what I expected, but I love the experiment. What mount are you using on the Jeep? I’m picking up an FT-857D and ATAS-120 this weekend. You have no idea how much I appreciated your out takes. It’s part of the content producer game. 73

"Turns around a point," it's a thing, hey, even prospective pilots have to have a little fun too!

That's /P NVIS (portable) as you can not drive with a wire in a tree ;)

Outstanding, many thanks for that. 80m may be a better choice for NVIS depends on what part of the world you reside in. The important thing is that you get out and try it which is exactly what you have done and made a very interesting video at the same time. Good stuff.

I do not think a mobile is a true NVIS antenna. I think that is where the problem is. The true NVIS antenna has a crazy elevation angle, pretty much straight up. I've not done much personally but have read some, and see examples of NVIS antennas with huge metal "reflector" arrays under them. They are not ground planes, but instead reflectors. That seems to be crucial for a good NVIS antenna. Antennas really are taxing from the brain power side, and the programs which try to help in computers can be a direction to go to. Great to experiment with an attempt at using ft8 or ft4 mapping as a results graph, couldn't do that 5 years ago.

The "incessant Cessna" is what I call those low, slow, and noisy aggravations to the out-of-doors. When they get stuck in a headwind, they hang up there forever! Is 20m too high in freq for NVIS? I should work up a mount so I can deploy my half-wave all band from the car. Thanks for vid.

Would a ATU be needed for 80M on your wire which you manually tuned for 1/4 wavelength of 40M?

Shouldn't that counterpoise be connected to the vehicle ground ? Didn't see if you did that

How long was the antenna wire you used. That was not mentioned.

Great video, I've wanted to do the same test with my Yaesu ATAS120. Does adding the whip back on top of the wire create an L type or does it mess things up because the screwdriver portion and the whip would put the wire in the middle?

unfortunately this is a portable configuration, not a mobile configuration, but an excellent video. I am looking for something that will be truly mobile when off roading

Did you take into account that you changed the whip length and in doing so changed the SWR? And the resonant freq. Cut the wire to a 40 or 80 meter freq and put it on without the coil.

3 questions: When you removed the whip and switched to the wire, did you retune the Little Tarheel? I have that setup in my truck with a IC-7000 and use a Turbo Tuner to adjust the LTH. What length of wire did you stretch out? And, lastly, do you have corrosion issues with that quick disconnect? Even in dry Arizona I have had issues.

Another excellent video. I looked too fast and I read NCIS oupsssss. Did you have time to have a solution for the Raspberry Pi 4 ?. 73 VA2SOB - 73

For some reason I can't consider this to be "mobile". Just because the antenna is mounted on the car and the radio is in the car doesn't mean it's mobile. Seems to me that to be considered to be mobile, one must be able to operate while driving down the road. If one can drive down the road, stop, and continue operating without making any station changes, it could be considered fixed mobile. But there is nothing mobile about this. Take the Tarheel and mount it on the hood of the car and lean it way over the top of the car. Does that work?

How would an inverted V fan dipole work out you think? 73 de ke4ooo

When you see a HUMV running around with its antenna pulled forward and tied to the front bumper, they are operating NVIS, usually digital. Also, those funny bars over the top of WW-II German Army Command Cars were not for RollOver or Rain Protection but was an NVIS Antenna which was in standard use along with their ENIGMA Code Machines via hand sent CW. The German Army was using NVIS at least as early as the 1920s as were German U-Boats during WW-I when close to their shore bases. Out to sea the same antennas used Skip at higher frequencies. All during WW-ONE! Many National Guard buildings have a 40M Dipole NVIS Antenna about 20 ft above the metal roof of their building operating Digital/SSB. In the 80s I used 40M and 80M Hustler Resonating Elements folded over the roof of my Ford StaWag on the installed hinge mount while both Mobile and Portable. I also used a 20M Resonator with a length of wire clipped to its top and stung out to a tree to operate 40M. I made many 40M NVIS Contacts using both setups with a TS-430 and a few on 80M, all SSB Phone. At this QTH I have an 80M EFHW Slopping Inverted ELL going up on a 40 foot SpiderBeam Mast and slopping out to a tree limb 100 ft away. Works NVIS SSB like a champ and occasionally a marginal SSB phone from NH out to MI/OH. A 40M or 80M EFHW is a multiband antenna. I can hear good on 20M but haven't been able to make a solid contact yet. Drats! Must cut a 20M EFHW wire and try that as a virtical W/WO a few radials. 73 OM KA1RUW.....

Nice video (perhaps the airplane was looking for other activities in the woods...). 73, kk4zuu

Thanks for the video. NVIS propagation can really be different from day to day and lately it seems like it's been a little on the long side. Last week I tried to make a 40 meter QSO with a station 150 miles away and couldn't do it all day or the next but on the third day it worked great. Switching to 80 meters fixed the problem and I could make the contact all day long every day. So right now at least, 80 meters is a much better bet for NVIS. I've found this website very useful for checking on realtime and historical NVIS conditions. lgdc.uml.edu/common/DIDBFastStationList I pick the Austin station as it's closest to me. Then go through each page picking your date and time. When you finally get to the report page look at the top left "foF2" number. That's the highest frequency that was shot straight up and came straight back down again. If you want true NVIS distances you need to operate at that frequency or lower. At the bottom of the page gives you max frequencies for 100, 200, 400, etc NVIS ranges in kilometers. I have found it to be pretty accurate to real life communication abilities. Your antenna setup will work fine for NVIS as it will radiate a good chunk of your signal up just as it is. Lengthen the wire some and drop to 60 or 80 meters for our current conditions.

Ever thought of a roof mounted fold up magnetic loop?

Great video Jason. It inspires me to do some more experiments. If I had a big van I would do something like in this SGC 231 manual page 19, 20 www.sgcworld.com/Publications/Manuals/231man.pdf Maybe this is what Ronny Julian s talking about You could use your antenne base instead of the SG231

The title was a little misleading. If you're tied off to a tree you're not "mobile," you're operating portable. I was hoping for ideas on how to get NVIS performance while driving down the highway.

Your propagation is still NVIS

Other NVIS..."OH5ZN´s mobile magnetloop 3 - 16Mhz"; www.dropbox.com/s/8sasnor7gxu1igz/mobile_mag_loop.jpg?dl=0

What would it do if you did a full 1/2 wavelength center feed?