Yaesu ATAS-120A Part 2 (Installation and First Contacts)

I was gifted a Yaesu ATAS-120A by one of the members of the Patreon support team. Needless to say, I am very grateful. The members of the N4HNH Radio Patreon team are a cut above. I started offering the Patreon support option in late September of 2020. Some have supported the channel, via Patreon, since October of 2020, making it possible for you to watch this video today.
I have recommended the Active Tuning Antenna System, based upon the results of people I know, but I haven’t had the opportunity to use one myself. The feedback from those who have installed one for their mobile operation has been great. I look forward to getting one installed on my truck.
This video shows the installation process and some initial testing of the Yaesu ATAS-120A with my Yaesu FT-891.
I hope you enjoy this video and find it helpful. If you find my channel informative and entertaining, I hope you will consider joining my support group by clicking on: www.patreon.com/N4HNH There are 3 levels of support, including exclusive content. Patreon team members gain insight from our technical discussions and internal polls. They also have the opportunity to view certain videos before they are released for public viewing.
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73, de N4HNH

[@tpobrienjr]

Looks good. I have ATAS-100 and FT-100D and will try your setup on Explorer XLT!

[@n4hnhradio]

I like this setup very much.

[@dwaynefradd85]

I've had my Atas-120A for years and love it. It does quit working after a couple of years but all you have to do is take it apart & clean the sleeve & it works again.

[@dwaynefradd85]

The more grounding you can get under it the better.

[@n4hnhradio]

I hope mine doesn’t quit but I know at some point most things need maintenance. 73, de N4HNH

[@alsanderson4917]

During TX, if you hit the up or down button on your mic, it will fine tune your ATAS in small steps. For you SWR perfectionists.

[@af4od02]

I’m going to have to try a ATAS

[@n4hnhradio]

I’m liking the convenience. The performance is better than expected too.

[@k5wxp22]

Great video, and thorough! I ran one of the same setups in a hybrid Camry for a year or so with great success, even when folks said it couldn't be done. Now running in my F150 pickup behind the cab on a corner mount with a Breedlove puck. I think I would like being able to see the antenna tune, but also think it would drive me crazy being in my line of sight! Yeah, it's a compromise antenna, but really, all of them are one way or another. The size and tuning convenience are what makes this combo so cool. Going to watch your 3rd video now... keep up the great work! 73, Brett

[@n4hnhradio]

Just wait until you see video #4 in a few weeks. It might surprise you. I don’t mind the antenna being mounted up front. But I definitely cannot tune while driving. Yaesu advises not to tune while driving anyway. It has caused premature failures. Your cab probably provides a bit of protection against the wind load.

[@k5wxp22]

@N4HNH Radio looking forward to it! I have been out of radio for a while for various reasons. Your videos are very informative and inspirational. Many thanks!

[@n4hnhradio]

I’m glad you find the channel helpful. 73, de N4HNH

[@k5wxp22]

@N4HNH Radio such a coincidence... on a live stream chat from K1GMM today and Steve mentioned your Channel/site as a great resource. Had me chuckling as I have been watching your videos over the last couple of days. Looking forward to part 4. 73, Brett

[@n4hnhradio]

Small world huh? My channel is small. I’m non-commercialized, funded by viewers. Only 8,700 subscribers. What are the odds that you would randomly run across another viewer? Amazing! I appreciate Steve spreading the word.

[@robertcastellow5797]

I have my ATAS mounted on the back edge of the back door on the drivers side of my 2003 Silverado, same truck as yours without the Avalanche upgrade. I am using the K400 mount. I have another K400 on the back edge of the hood for my VHF/UHF antenna. I don't even see the antenna unless I look for it, my mind blocks it out like looking through a window screen, you don't see the individual lines of the screen unless you focus on it. I have a FT-891 for HF and a FTM-400 for VHF/UHF/APRS. I did buy a mount similar to yours but did not for the Silverado. I do have one for my Dodge Dakota for VHF/UHF. I will have to ger one for the Silverado and move the antennas around. Keep up the videos. 73 Buzz KD4CXI

[@n4hnhradio]

Hi Buzz! I also use a K-400 for my VHF/UHF. It’s on the passenger door. Been there since 2005. No issues. I still have the new Diamond mount that I didn’t end up using, in case I need to move it to the hood, like a couple of my friends did. But, if this works out, the antenna stays put when I raise the hood. I had to go back and add lock washers to the UHF connector, and some Loc-tite. It loosened from the wind turbulents of the semi trucks on the Interstate. It seems to be solid now. 73, Doug

[@RichKielbasa]

Gotta have it!

[@n4hnhradio]

I am very pleased with the ATAS-120A. It has exceeded my expectations. I think you will like it. 73, de N4HNH

[@ghostmandka5498]

Nice Speed 55 speaker ya got there!

[@n4hnhradio]

You recognized that old speaker? It is labeled as a Yaesu.

[@VE3AVA]

Hey there. Thanks for posting these videos. I am considering an ATAS 120a but I have a quick question. Are you able to handle highway speeds with your mount setup? I just wonder with something with a width such as this having trouble at a higher speed. Thanks again!

[@n4hnhradio]

I drive on the Interstate highways with it. You just cannot initiate a tune cycle while driving that fast. I wait for slow traffic or a traffic light to change bands. But I can just press a button. I don’t need to exit the vehicle.

[@randyvaughankn4wbh998]

I believe there is a bolt closer to the hinge point that also works,, bringing the antenna closer to a piller and less out of drivers view

[@n4hnhradio]

Yes, but no opening for the bracket to fit into. Plus the hood hinge spring is in the way. Even in the current mounting place the hinge is very close. I had to repair the connector because the hinge spring caught the coax and cut it. Fortunately it only cut 6 inches of coax, so I was able to repair it. What you see in the video is after the repair. I ty-wrapped the coax to the forward most place I could, in order to get it far enough away from the hinge spring.

[@lonesomekennels5047]

I noticed in the 7.150 comparison the ATAS120 was a 2.0 swr and the Ham Stick was 1.5. Obviously this affected the performance as well. I agree that the convenience means a tremendous amount in using the ATAS 120.

[@n4hnhradio]

Yes, those were first contacts, after the installation. I have improved the bonding to the body with more lock washers and the SWR is lower, around 1.5:1. I can also fine tune with the Up/Down buttons on the microphone, but it is touchy. The difference between a 1.1:1 and a 2:1 on the other station’s S-meter is about half a needle width. In the old days of amateur radio, they were happy to get a 2:1. Louis Varney (G5RV) designed his antenna in hopes of achieving a 2:1 on the 20-meter band. The old tube type transmitters didn’t care about a 2:1. They just kept chugging along. The solid-state finals used today prefer 1.5:1 or less but 2:1 can be tolerated. The foldback circuit should protect the finals if they overheat. Many hams are obsessed with SWR these days. 1.5:1 or less is ideal. 2:1 or less is tolerable.

[@lonesomekennels5047]

I was thinking along the lines of the received signal. I have one of these ATAS 120 antennas on the way. I’ve run Ham Sticks, Hustler Resonators and a Tar Heel in the past. I’m interested to see how this little antenna performs. 73, KF4GNV

[@n4hnhradio]

The difference between 1.5:1 and 2:1 on receive is even more negligible. I don’t think the ATAS-120A will outperform a Tarheel, when mounted to the same vehicle in the same location with the same bonding. They’re both just using coils of wire to make the antenna appear long enough to the radio. Nothing beats having more wire in the air. But, the ATAS-120A is a screwdriver type antenna that requires no additional power or control unit. The Yaesu radios power and control the antenna via the coax. The draw for me to the screwdriver type antenna is the convenience of not needing to exit my vehicle to switch antennas when I change bands. The ATAS-120A, and any mobile antenna with a coil to fool the radio, will be least efficient at lower frequencies, especially 7MHz and lower. So I’m thrilled to see the ATAS-120A perform as well as it did in this video. It was only beaten by the ham stick in this video because the stations on 7.150MHz were in its null. As I drive around, and position my truck so I have the right rear pointed in their direction, the ATAS-120A beats the ham stick by 2 S-units. An antenna mounted at the front left will have a strong lobe toward the right rear direction. This gain toward the right rear came as a tradeoff for lower gain toward the front left. The ham stick, mounted at the top center of the vehicle, has a more circular pattern, with no major lobes of gain, or nulls.

[@billholt5573]

My impression is that the ATAS does not tune for best SWR but for optimal. Once it is in an acceptable range it stops tuning even if another turn on the coil might be better. At least that is what mine seems to do.

[@n4hnhradio]

You are correct, Bill. I can press the Up or Down button on the microphone while transmitting and tweak for lowest SWR, but it isn’t necessary. No one on the receiving end can see or hear the difference between a 1.5:1 and a 1.05:1. Not going to happen. People are too obsessed over SWR. The old-timers were happy with a 2:1, because they used tube finals. Louis Varney, G5RV, designed his antenna to provide a 2:1 on the 20m band. Modern radios, with transistor finals, don’t like to see a 2:1 SWR but are fine with 1.5:1.

[@thormusique]

This is a great video, Doug, thanks! I've been thinking of mounting an ATAS on my vehicle as well. I do like the Ham Stick option as well; it's nice to have choices. Does the triple-magnet mount hold well, even at highway speeds? Anyway, another great video, cheers!

[@n4hnhradio]

The triple magnet holds to 80MPH. I never tried faster than 80. It is only capacitively coupled to the truck, hence the need for a touch-up antenna matching unit, especially for 40, 60, and 75 meters.

[@thormusique]

@@n4hnhradio Ah, I see, that makes sense. Thanks!

[@n4hnhradio]

Watch the rest of the series and you will see what happens.

[@Medic-ui9ms]

Any idea of RF performance differences between the Little Tarheel and the ATAS? I went with the Tarheel several years ago, mainly based on weather intrusion issues locals I know have had in the long term. If I was going to add an antenna for a second vehicle though I'd still probably grab an ATAS to try. Enjoy your new setup and thanks for the video! 73, NJ0Q

[@n4hnhradio]

I have a couple of friends who have a Tarheel and one thinks my ATAS-120A is outperforming his Tarheel. He has said emphatically in the past that my ham sticks outperform his Tarheel. But, it isn’t a fair comparison. The RF ground (aka counterpoise) is so vitally important for these type antennas and his Tarheel is mounted to the back of his Jeep. The counterpoise (aka RF ground) is compromised. There isn’t much in terms of a ground plane for the antenna to work off of. With a mobile antenna, the vehicle must act as the other half of the antenna. I think the best way to compare these is to mount them both on the same vehicle in the same location. I have another friend who has used the Tarheel, and he personally knows the owner of Tarheel. My friend now uses the ATAS-120A. What I know is this. My 6 to 7 foot ham sticks, mounted dead center to the top of my truck, have consistently amazed people when I say I’m mobile. I get unsolicited compliments. I’ve broken through DX pileups while making a run to the grocery store. I’ve used ham sticks since the mid 1990s and I’ve been impressed. So I had no expectation for the ATAS-120A to top my ham sticks. Stay tuned to future videos in the ATAS-120A playlist. It might shock you.

[@AE6Z]

@@n4hnhradio K8MRD did a comparison b/w the Tarheel and the ATAS on his channel recently.

[@ac7fd]

@@AE6Z I don’t know what he did there but I had the little Tarheel with Targetuner and the ATAS 120 on my truck over 2 years and I don’t see the results he had. There is no significant difference with stock whip. The Tarheel is definitely better with longer whip which is an easy upgrade on the Tarheel due to the standard 3/8-24 thread. The Atas has a thin whip secured by two set screws. All that said, it’s easy: if you have a Yaesu radio you get the Atas 120. Mount it, change 2 menu settings and the antenna is ready to use and does it all automatically. The Tarheel needs an additional controller to have similar comfort. If your radio isn’t Yaesu: the Tarheel is a good choice.

[@donausmus4281]

Just finishing up my install in my Ram 2500. Have you tried installing three 33' counterpoises aligator clipped to the antenna base, spread out in a fan pattern on the front left of vehicle?? Three 16's might work as well.

[@n4hnhradio]

No, I haven’t. I use this setup while driving. As soon as I start moving, the counterpoise wires would get dragged.

[@donausmus4281]

@n4hnhradio I will try it parked for a POTA, of course.

[@n4hnhradio]

Maybe it will help. Some verticals actually perform worse with additional counterpoise.

[@TingILi]

I had ATAS-100 as probably 20 years ago. I sold it because the performance is quite flat, which means I can hear somebody but they mostly don't know anything. But I did some QSO to China mobile station where from Taipei. Right now, I really think, do I buy ATAS-120A for my FT-450A and FTdx-10.

[@n4hnhradio]

I am quite pleased. If the ATAS-120A was mounted atop the truck, it would probably equal the performance of the ham stick in the same place. The ATAS-120A has consistently beat the ham stick when I position the right rear of my truck toward the other station. This video was a worst case scenario for the ATAS. The stations on 7.150 were in the direction of least radiation - front left. The ATAS-120A has equaled the ham stick in other directions and routinely beats it toward the rear and especially right rear, as expected. The main lobe is toward the right rear of the truck. 73, de N4HNH

[@dovetomarc]

Did you have to do much bonding work?

[@n4hnhradio]

No bonding, other than the bond through the antenna mount. And it is held by an existing bolt. No holes drilled.

[@_PikeWxRadio]

I notice that you do not use a mount through the roof for either VHF/UHF or HF. If you had a mount to use would you put the ATAS on the roof? You mentioned low power lines or maybe branches but I'm debating if the benefit of a roof mount would outweigh the hazards one would encounter. My elmer insists that screwdrivers should not be roof mounted because of the wind load, but I cant imagine that it would be any different on the hood ahead of the cab. Im mounting on a 2009 silverado and refuse put it anywhere in the bed where it could interfere with anything i would put back there. I have an aluminum tool box but that would be more of a compromise than id like to deal with and theres no decent location on the cab to mount otherwise. Any thoughts would be appreciated.

[@n4hnhradio]

Top center of the roof provides a more omnidirectional pattern but at the risk of damaging an antenna that costs almost $400. I’m perfectly happy with where mine is mounted. It has a strong lobe to the right and rear, which outperforms the top center mounted ham stick. Wind load can increase as the air flows over the top of the vehicle. But there is also wind load where mine is mounted. The instructions say not to tune the antenna while driving. I tune at a traffic light or I pull over on an Interstate highway. At least I don’t risk getting hit, having to get out of the truck switch out ham sticks. It would be better behind the cab but I’m not sure if the counterpoise would be as efficient.

[@_PikeWxRadio]

@@n4hnhradio Thank you for the reply. Yes the cost outweighs the need to roof mount it. I found a BreedLove Mount that will fit under my toolbox. Hopefully that does the trick. I was just hoping to avoid it being in the way. Either way ill be going to town on bonding the whole truck together haha. Looking forward to the next videos!

[@paulsharp5473]

Are those leaves still there?

[@n4hnhradio]

No, I replaced those leaves. The others got washed away by the car wash. The new ones are just as ornamental as the old ones though.

[@jerryKB2GCG]

another advantage, you don’t have to change sticks when you change bands, that’s the big draw for me.

[@n4hnhradio]

Indeed it is, Jerry. And this thing is performing well thus far. Two long range mobile to mobile contacts, and they were both ATAS to ATAS.

[@jkruse1151]

Your test between the ham stick and the ATAS antenna is not fair because you never adjusted SWR on your ATAS and you are losing power with the higher SWR through the antenna. If you attempted to adjust the swr and if you could get it down your power output would probably picked up a little bit better. I’m not gonna say it’s gonna be a world change, but to be fair I would’ve tried.

[@n4hnhradio]

The difference between the ham stick at 1.6:1 and the ATAS-120A at 2:1 is negligible on the receiving end. QSB makes more of a difference than a 0.4 change in SWR. People get obsessed with SWR. The old-timers were happy with a 2:1. They knew that their tube finals didn’t care. They knew that the difference between 2:1 and 1.1:1 on the receiving S-meter is barely discernible, assuming the receiving station is watching their S-meter. It takes an increase from 50W to 100W to move an S-meter 1/2 S-unit. Losing 3-4W because the SWR is 0.4 higher will not likely be detected on the receiving end. Those guys reported a 2 S-unit difference. That’s more than a loss due to SWR. It’s the mounting location of the antenna. Keep watching the series and you will see why. The ATAS-120A stopped at 2:1. I didn’t stop it. It can be fine-tuned if desired. Yaesu knows that the FT-891 will begin to fold back the power above 2:1. They also know that the difference between 1.5:1 and 2:1 might be a needle width on an S-meter. As I have used this antenna all year, I notice that it usually stops between 1.5:1 and 2:1 on 40m.

[@imposter6380]

Having that in your field of view while driving is probably no good

[@n4hnhradio]

It’s no bother. I only notice it when I wish to.

[@vomKuckucksfelsen]

Not that polite to tune on a frequency that was in use...

[@n4hnhradio]

It would have been rude, had I not known them and told them I would be testing. Plus, they run an amplifier and keep their RF Gain rolled back. They didn’t hear my 10W of tune-up power. And this is a high-Q antenna. Move a few kHz away and the SWR can use a touchup. That’s the nature of a high-Q antenna. So, if I tune up 5kHz away, I will need to retune when I get to the frequency where I want to operate. Are you the RF police? Go clean up 7.200!