Vehicle Mounted Regional Comms - Part 1: ATAS-120A

The military has been using vehicle-mounted NVIS antenna deployments for decades to support offgrid, local and regional comms. In this series, I am going to try several antennas. We'll see which ones work and which ones fail.
Here's my first attempt using the Yaesu ATAS-120A.
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#thetechprepper #nvis #jeep #atas120

[@longtonailtrdwtr8715]

I use a Tarheel antenna little Tarheel. It’s mounted using a similar style trunk/lid mount on the rear driver door, about midway up. This put top 3 inches of the coil slightly above the roofline with a 58” antenna vertical above the roof. I believe this is effectively a 12-13’ vertical and I’ve worked from Kentucky to NC on voice at 10w. I semi reliably get SSB contacts at 10w. This past weekend I used a 100w radio and was easily making SSB contacts. I think a lot of it is overcoming the severely compromised antenna on HF with propagation and wattage.

[@WeaponsJunkie]

Keep working. This is great. Excited to see a solution for the same challenge as well.

[@racerveza4904]

Wow, good timing. I opened YT to look for ATAS-120 reviews, and here you are. I've got the same objective as you - quick deployment of a stationary, vehicle-based station. I can get on the air in about five minutes with my CHA-TDL mounted to a bracket on my receiver hitch. Looking forward to your next experiments. 73 de W9DNE

[@TheGeekiestGuy]

I'm always looking at different atas mounts. Thanks for the inspiration, brother. We went to do a POTA today, and the main club radio didn't have its power cable, so we ended up using another members 818. It didn't go very well, but lessons were learned. 😆🤙🏾

[@vironpayne3405]

You might stand up the loading coil vertical. Then clip a wire to the tip of the whip. Then connect the other end of the wire to a fiberglass pole on the rear of the Jeep. In essence you would have an Inverted-L antenna that is base loaded on the vertical. Jason KM4ACK does something similar for his portable HF operations. Others also have done similarly. The proximity to the roof will be an issue, especially if it is varying while you are underway mobile. I used 102" CB whip on top of a homemade loading coil fed thru an SGC antenna matching unit at the base of the loading coil. The whole arrangement was on a bicycle carrier that mounted in a trailer hitch reciever. On the interstate the wind pushed the whip back to where I got good NVIS performance on 40m and 80m.

[@TheTechPrepper]

I typically run the ATAS vertically on both the Jeep and the RV, but I get a lot of skip, hence this experiment. However, trying to run that traditional configuration with as an inverted-L is intriguing. In the end, that will be too much work as the goal for what I am setting out to do is to have reliable NVIS propagation in under 90 seconds. I think the ATAS 120A can be made to work, but it is not enough juice for the squeeze. It's time to move onto another antenna systems that has less deployment challenges. If the FT-818ND supported the ATAS, then it would have been a different story. I appreciate you thinking out of the box on this one.

[@DrFredism]

Thanks for the experiment!

[@TheTechPrepper]

Any time!

[@IndependentNewsMedia]

If you utilise a longer whip which is long enough to reach the boot [UK] or trunk door [US], you will get NVIS'ish, try to get a much of the whip section over the flat roof. Note there will be nulls due to the body of your vehicle, try to find the nulls they are useful; when you have local'ish interference, you can drive and turn the vehicle with trial and error pointing the null in the direction of the interference and increase the reception quality, works OK'ish on HF, and however VHF/UHF can change from s1 to s5. Keep up the good work, God bless.

[@rufusrizzo78]

You could go expensive and get an ICOM AH-740 Mobile HF Auto-Tune. It may reach past the bumper...

[@jayzee1968]

Good stuff man. I’ve been thinking about the same lately, how to setup for HF comms between vehicle and home stations. Nvis was on my mind also for that 150-300miles range. Looking fwd to see what you got setup next.

[@thuff3207]

I do enjoy your videos and I have a tarheel on my jeep similar to your antenna. I am not sure what year your jeep is but mine has an aluminum hood that will not support the K400 without bending it. I opted for using a light mount on the a pillar to mount my antennas. I hope your hood is steal and not issues.

[@JohnTarbox]

If you look at the tests the US military has performed, they have had very good luck with vertical whips mounted on the back of humvees, where they use rope to pull down the whip's tip behind the vehicle. This would be easier when parked rather than in motion. DE WA1KLI

[@DavidS-iw4ei]

Nice setup. Try the Yaesu FC-40 and a 102" whip. You will see that, as you change the freq on the radio. The FC-40 will follow the freq as it tunes. The FC-40 is about $275 dollars.

[@TheTechPrepper]

Great recommendation on the FC-40. I've been considering that unit for years. I've never been a fan of tuners, but I may have to make an exception here.

[@Swamp-Fox]

Can't wait to see what you have up your sleeve with your next whip style deployment. The only way you can find out what works is to try it!

[@TheTechPrepper]

Here's a bit of spoiler. The test will be using a 3/8 adapter on the K400 mount, a Hustler 40m mast, and a Hustler 40m resonator. I'll fold it backward when in motion and forward when stationary.

[@robertengel8342]

Keep up the great content

[@TheTechPrepper]

Will do. Thank you for the support.

[@rufusrizzo78]

I have been shocked at how well HAM sticks work. I have done well with 20m and 40m hamsticks. They tune the whole band well. If you want NVIS a bumper mount may work better.

[@TheTechPrepper]

I regret selling a pair of 40m Shark hamsticks at the last hamfest. I had a terrible time tuning them for a vertical dipole deployment. I may pick up another one if my next experiment does not go well, but I think it will work out. I am testing a new setup using a Hustler Resonator. 73s

[@rufusrizzo78]

@@TheTechPrepper cool. The resonator look to be narrow BW, it would tune well for data. I'm looking forward to see how it works for you. I was shocked my 80m hamstick was very narrow band. It makes sense that's a lot of wire to cram on a 4ft fiberglass pole with a ~4ft whip.

[@codygingery1495]

The atas120 is a great antenna for hf

[@TheTechPrepper]

It's been handy. I primarily run it on the motor home as I have one heck of ground plane with all bonding that I did on it a few years back. I haven't done much with the Jeep yet.

[@codygingery1495]

@@TheTechPrepper ive been running it on my car for pota, and ive gotten italy, and alaska, and all over. So it definitely radiates well. Just interested to see how it works angled for nvis, concept looks like it should do well, similar to the humvees

[@donausmus4281]

I love mine! Have it mounted on a Ram 2500. Have 25 bonding straps connecting everything.

[@Subgunman]

Have both th3 Little Tarheel with a longer whip as well as the ATAS 100, the predecessor to the 120. Both are decent antennas. Have used the 100 as a base antenna with the accessory ring that has three different coil loaded whips for its ground plane. Works good in receive so TX will not be a problem.

[@TheTechPrepper]

Thanks for the info!

[@MrStanwyck]

I always enjoy your videos Gaston. That’s a nice looking jeep setup you have. Have a good evening…

[@wed_ward]

I'm doing similar tests as soon as I decide on the antenna(s). I was looking to start with some sticks (reg or mini) and mount them parallel and offset from the roof rack rail on one side and play with 40m. My issue is finding someone local to test with. I'm playing off the typical helicopter mounting to see if that will work.

[@dougdaniels]

Not sure what model that Jeep is, but if it's a JK, there's a great antenna mount for the rear license plate bracket. I got very good tx/rx with it when I had mine.

[@TheTechPrepper]

Yep, it's a 2016 JK. I'm experimenting with a number of mounts, including the one that you are describing. I plan to film each experiment and varition... success or failure. Stay tuned.

[@deerslayer767]

I thought about this antenna. But here up in western Washington I just feel like it would suffer damage. Lots of one lane roads with vegetation. I hear they are excellent antennas.

[@Cr0cket20]

I too would like to have NVIS setup in the truck. Interested to watch your findings.

[@TheTechPrepper]

More in the way. The truck is a much easier platform than my two-door Jeep JK, but the principles should apply. Take care.

[@JohnJones-op8uf]

The ATAS 120a I had was a pos.... I had to send it in for repair after only 2 months. And still it was unreliable. Radio was FT-891

[@Mark300win]

Mechanical hardware are prone and bound to fail! Army humvees have remote auto tuners with a whip for a reason

[@kc8owl]

lets try this one more time when you want - my base JS8 station was offline while I was experimenting with the manpack this morning. :-)

[@TheTechPrepper]

Roger. Let's do that. This will be my 4th test... It's not looking good. Also, note that the FT-818ND can't tune this antenna, so this setup may be a deal breaker. I should retest with the 857 manpack at 20 watts or more.

[@VeteransHamShack]

I have a 2015 Wrangler Unlimited Sport. I've been trying to figure out how best to mount an antenna since the Wrangler has the fiberglass top and mine has the factory plastic bumpers. That Diamond antenna mount looks like just what I need. @Blackabeard (Blackbeard's Radio) sent me over here to check out your videos on your Wrangler. Question - Have you had any issues with the antenna bending/denting your hood due to the weight of it and the sway in the wind? I read somewhere that could be an issue. Anyway good video, subbed. I've got an FT-857D that Ive had for probably 10 years and just drug out of storage. Looking forward to getting back into the hobby

[@TheTechPrepper]

No issues with the K400 mount. I have been running it for almost 4 years. The ATAS-120A is a heavy antenna that rarely runs the Jeep as it is usually mounted on my K400 on the RV.

[@crakkajakka15]

Question. You had a video i watched a while back where you printed cards with quick programming information that you kept with you radios do you have that template you used for that to share?

[@rheacecontracting]

Would I be able to do something like your manpack with the hytera hm782

[@bob45663]

Could you please give us the top 5 HT's that you would recommend?

[@DellFargus]

I'm not familiar with the ATAS, so I'm assuming (ass-u-me) that it acts as a vertical antenna with a spherical radiation pattern that is flattened by the ground plane created by the sheet metal on the vehicle. Would it be worth mounting it on the fiberglass roof of the jeep to remove the metal groundplane? The groundplane lowers the takeoff angle, so removing it may give you a desired NVIS effect.

[@timK0WTB]

A little off topic, but I have a JK as well and while HF works alright, I get a massive amount of RFI on 2M that goes away when I pull the stereo system fuse. I’ve tried to locate the offending component, but i’ve never pinpointed it. I am just curious if you see the same thing.

[@TheTechPrepper]

Interesting. I can't say that I have experienced this. I've been running 2m/440 for over three years off the same mount and Comet SBB-5 with the D710. Good luck.

[@LeopardAppaloosa755]

Reorienting it vertical should make a huge improvement.

[@TheTechPrepper]

That's how I always run it, but I get too much of a skip zone. I was trying to see if I could get some horizontal polarization so that I could hopefully experience some NVIS propogation. I am trying to experiment with some mobile options for regional and state level communication. I am pretty my next setup will do the trick. Thanks for the suggestion.

[@Superacerc]

I have success stationary angling the antenna away from the vehicle

[@TheTechPrepper]

I've had better performance with a telescoping whips (not this antenna) in the past, positioned away from the body as well. However, this ATAS-120A doesn't work well going off any angle--off the front or off the back. It only shines as a vertical. I was curious to test it since I have it. I tried several more experiments with this ATAS-120A this afternoon, but it's looking like trying to get high angle radiation from this antenna is a hard no-go for NVIS.

[@Superacerc]

@@TheTechPrepper I've never used the atas. Only other brand screwdrivers from high sierra(back around 2008) tarheel, and diamond.

[@timevans239]

Awesome video. I do have diamond mount on my jeep right front hood. Also i have a mount in rear of jeep were i can mount my ATAS 120 Antenna. Thank you so much for your videos. Kg7fxn

[@Flatus4La]

Hamstick with mag mount?

[@Flatus4La]

Gaston ... is 160 a good price for a FZ M1? Thx!

[@Superacerc]

The stinger is probably interacting with the metal body too much

[@TheTechPrepper]

There's not much metal on this Jeep, but, yes, it's likely interacting with the roll cage.

[@HardcoreFourSix]

are you looking for NVIS capability while in motion?

[@TheTechPrepper]

Not really, but that would be a bonus. The most performant deployment would require me to be stationary anyhow. The goal is to be able to pull off the road and deploy the antenna system in under 90 seconds, then pop back into the vehicle to hit a quick commo window. More tests are coming. This was just the first.

[@paulplack490]

@@TheTechPrepper How about a roof-mounted plastic reel with 66' of wire, banana plug on the end attached to the reel center, insulator on the far end, and a tuner? If you could park 70' from a small tree or other vertical support, pull the wire out, anchor the far end with a bungee, and plug the banana plug into a lead from the tuner, voila! Quarter-wave fed against the vehicle ground at NVIS height.

[@vironpayne3405]

What the military has done when they stop is they pull their HF whip into a horizontal position over the ground, not the vehicle. The only question is "How do you hold the antenna horizontal?" That is mostly a matter of preference. Jason-KM4ACK uses a quick connect on his Lil Tarheel antenna whip and alternate length of wire with a quick connect. The biggest factor is gaining efficiency by running longer wire. I would try close to 50ft on any loading coil and you should have good efficiency on 40m. Working like a NAZI hun you could accomplish deployment in 3min. Another option would be a 1 or 2 turn horizontal loop based on the 4 corners of your vehicle. Have posts mounted to keep the antenna at least 18" away from metal on the vehicle. Feed the loop with a wide range matching unit at the antenna. The loop on 40m would be close 1/4 wavelength and have reasonable efficiency. When designed well mechanically you should have reasonable efficiency and band agility when mobile. SGC mentions using their matching units with multi turn loops for indoor wall installions. I think they suggest up to 4 turns. In a few years you need more 5W and 60m or 80m. For car mobile there is no reason not to use your FT-857. You'll get something good going. Cheers!

[@cpt.moroni3092]

Any updates?

[@TheTechPrepper]

The ATAS-120A is a no-go. I'm having exceptional success the Hustler RM-40. There's a lot of updates on Instagram. The last video showed a bit of the Jeep updates. A full length video is coming soon.

[@danford7532]

With your antenna close to the jeeps metal, you're radiation pattern will be negatively impinged upon. Try putting the the antenna on your back away from metal.

[@TheTechPrepper]

I plan to try that with the next deployment. I have a mount that mounts above the license plate. This ATAS-120A is too much work as it requires automatic tuning by only a handful of radios (FT-857/897/891) that I have, but don't really run anymore. The next antenna is tuned manually. More experiments coming.

[@DominicMazoch]

​@@TheTechPrepperMFJ does have an adapter which converts the AH-4 Icom commands to ATAS.

[@DJCryptoStix]

OK good to know don't do that

[@glenng.8254]

Atas120 is junk.

[@TheShawna1]

I had the same jeep I used a windshield mount for mine worked awesome! i think i had taped the mount for the ATAS and it screwed right into it so the whole bottom face was supported for going offroad.jim KB1PFL