Yaesu ATAS-120A Part 5 (how many watts for tuning?)

[@VE3NMW]

First video I’ve found finally going over this!! Thank you!

[@n4hnhradio]

It’s a great antenna. Beyond what I expected. If you watch all 5 videos, you will see my skepticism proven unwarranted.

[@Superbadmike]

Thank you!!! You are the only one that actually has been able to awnser what ive been searching for a long time i have same radio and same Atas 120A antenna. Thank you sir !! My ATAS antenna sometimes takes a bit long to tune but i have good ground

[@n4hnhradio]

I’m glad you liked the video

[@MrTommy001]

Boy, I stumbled on your video just in time. I installed my new ATAS-120A antenna yesterday and tried it out. I was wondering if I would have to turn the power down on my 891 in order to tune. You have answered that question perfectly, with proof and all. Thank you for your time producing this vid.

[@n4hnhradio]

You are very welcome. This is video #5 in a 5-part series, made possible by a Patreon team member who donated the ATAS-120A and others who donate monthly or yearly to help keep my channel in operation without corporate sponsorship. That makes it possible for me to provide objective information.

[@kb9jqu]

Finally the mystery is solved! Thanks Doug for doing this. I’ve always wanted to know. I’m not surprised by the results. I always assumed Yaesu would cut the power during tuning to protect the tuner and antenna. Glad to see that’s the case.

[@n4hnhradio]

You’re very welcome, Curt. Inquiring minds want to know, right?

[@KT4LS]

Doug, the ATAS 120 series makes me want install my FT-891 in my truck. Thanks for producing this series!

[@n4hnhradio]

You’re very welcome, Lee. It was so nice to see you yesterday. My brother enjoyed meeting you too. 73, Doug

[@donausmus4281]

Thanks for your videos! I am in the process of mounting the Atas in my Ram 2500. The videos have been very helpful.

[@n4hnhradio]

I’m glad you found my channel helpful. I’m still very pleased with the ATAS-120A. I had a mobile to mobile contact, FT-891 to FT-891, ATAS to ATAS, from Atlanta to South Dakota. It was recorded. I hope to release a video of it. 73

[@boomerbits2297]

Still waiting for my ATAS. Back ordered! Shouldnt have returned the one I had a couple of months ago!

[@n4hnhradio]

It seems that everything good is backordered these days. It’s worth the wait, in my opinion. 73, de N4HNH

[@vickicarnes1905]

I shall try this tomorrow. AD3i

[@AK4PJ]

I had read somewhere on the Atas120 that it automatically switches internally to CW and low power even though the rig doesn't show that. That lowers the power and throws a carrier.. Not sure accurate that is but I remember reading it somewhere..

[@n4hnhradio]

As shown in this video. It automatically switches the meter to SWR, which is why I connected my meter for the video.

[@AK4PJ]

@@n4hnhradio I've played with my Atas120 and my tarheel 100 together. The tarheel definitely gets me better reports for the most part.. But because of the simplicity in the size & way the atas tunes, by automatically lowering power with just the touch of a button and then add the ease of installation it's hard to beat for a mobile.. Pairs perfectly with my 891.

[@frankENZC]

Hi Doug. Thanks for the Atas series videos. By the way I am really enjoying my FTDX-101D I purchased several months ago. Now I'm thinking of getting the FT-891 and the Atas antenna for mobile. I only have a hatchback car for now. Do you think the Diamond K400 mount will be strong enough to hold the Atas antenna on the K400 mount on my Hatchback? Oh, by the way, I see that the Atas Antenna goes to 2 meters. I suppose you could use an HT with the Atas. 73 de WA3RSL.

[@n4hnhradio]

Frank, I see no reason why the K-400 wouldn’t work with a hatchback. It’s made for trunk lip mounting but I use one on the passenger door for my 2m/70cm antenna, as shown in my Antenna Farm video. Two of my Patreon team members use a K-400 to hood mount their ATAS-120A. Another uses one as a trunk mount, for his ATAS-120A. I don’t know of an HT that could power the motor in the ATAS-120A and tune it for 2m or 70cm. A transceiver must be equipped with the control circuit and menu to control the ATAS-120A. Even with a Yaesu FT-857D, you will need a duplexer to use the antenna for HF/6m and 2m/70cm. A Diamond MX-62M should work nicely. Of course you could use a separate 2m/70cm transceiver. I use the FT-891 for HF and 6m. I use an ICOM ID-880H for 2m/70cm. But, instead of using a duplexer, I use a separate antenna - a Diamond NR-770 dual-band antenna, mounted to my passenger door with a K-400 mount. I hope this helps. 73, Doug

[@frankENZC]

@@n4hnhradio Thanks Doug!

[@Private290]

Still new to the hobby. Do you have to use a tuner if you install the 891 in your vehicle and use the atas? Trying to limit how much I need to install in my vehicle. Thank you

[@n4hnhradio]

An “antenna tuner” doesn’t actually tune an antenna. They are poorly named. An antenna tuner cannot change the length of the antenna. An antenna tuner acts like a transformer and fools the radio into thinking that the antenna is the correct length, so the radio can deliver full power to the coax. Much power will be lost in the coax, due to the mismatch between the coax and the antenna, but you will get some power to the antenna. Sometimes we have no choice. Been there and done that. As long as the antenna tuner is only needing to match an antenna that isn’t too far off, like 3:1 SWR or less, the coax loss is tolerable. The ATAS-120A has a motor that is powered via the coax. The FT-891 powers the motor and makes the antenna longer, or shorter, as it measures the SWR. It will stop the motor when the SWR is acceptable. I showed in video #4 of this series that I was removing the ham stick antennas. I no longer needed them, thus I no longer needed the FC-50 “antenna tuner.” I just released a video about an hour ago that shows my FT-891 as it is now - no FC-50. The FC-50 was disconnected during the filming of the 5-part ATAS-120A series. Now it is gone.

[@K7TDM_Tyler]

Interesting… I assume that the ATAS control is done with a DC offset on the output? How would that affect the power meter? Could the DC power be what you are reading? That would explain why the reflected power needle never moved. Could the RF output of the radio be much lower that what was shown here? Interesting test either way Doug. I hope to have an 891 and an ATAS in the moble soon. Thanks for the videos!

[@z3r0c00l2]

Very helpful. 73s Jimmy SY1DAL

[@n4hnhradio]

I’m glad you found it helpful.

[@z3r0c00l2]

@@n4hnhradio such an amazing antenna. Trying to figure out ways also to use it as portable but with a good ground , when not in car

[@martinvanek5951]

Good to know. Do you think the ATAS 120 would be a decent POTA antenna if used with radials? I alway enjoy and learn something new from your videos and Patreon perks. Thanks Doug.

[@n4hnhradio]

Hi Martin! KB9JQU has been killing it from South Dakota with his FT-891/ATAS-120A, operating from his truck. You should see his HAMRS contact maps. From California to Maine to near the North Pole to Europe. 73, Doug

[@martinvanek5951]

@@n4hnhradio Thanks Doug. I'm scheduled to go to Japan in October and will visit the Akihabara district where the HAM radio shops are located. In the past I have been able to purchase items there for far less than than I would pay here in the States. I'll see if I can pick one up when I'm there. 73

[@n4hnhradio]

Hi Martin! That will offset the cost of your plane ticket. There is a radial kit, if you wish to operate from a park without a vehicle. However, the radial kit only covers 6m, 2m, and 70cm. Maybe you could add a bunch of wire radials that are long enough to operate at lower frequencies. 73, Doug

[@ac1o]

question if i would run ft8 with the yaesu atas-120a what would be the max watts allow on this antenna.

[@n4hnhradio]

Yaesu doesn’t specify a FT8 rating but it’s usually half the rated power. But you shouldn’t run more than 50W from a 100W radio anyway.

[@ac1o]

@@n4hnhradio thank you I was wondering didn't want to over load the antenna with ft8.

[@n4hnhradio]

FT8 is very effective at 20W. 50W is a lot.

[@ac1o]

@@n4hnhradio once again thank you. I might try a Pota activation tomorrow inside my pickup. i will try the 20 watts on ft8.

[@z_bolin.]

Hi Doug, enjoy your videos. Just curious as to why the external swr/watt meter doesn't show the the reflected power as the antenna is tuning?

[@n4hnhradio]

Very observant Zach. The SWR needle isn’t working. I use my Autek Research WM-1 computing wattmeter for the shack. But, after I discovered how accurate the wattmeter is in my Elecraft amplifier, I even took the WM-1 out of line, saving another connection in the shack, and saving 3 feet of coax. 73, Doug

[@z_bolin.]

@@n4hnhradio thanks for the reply and as I always tell other Hams the less connections the less loss and get that power to the antenna lol 73, Zach W8MTE

[@n4hnhradio]

Yes indeed. There is no need to have three wattmeters when one will do. But one is in the radio and it only displays the radio output. I leave it set to SWR. The Elecraft displays watts and SWR. There is no need for a third meter and another coax in the chain. I run a streamlined setup. The only extra coax I have is the one from each radio that goes through the radio switch, allowing me to toggle between the FTdx5000MP and the FTdx10. That is a junction that I need, given the nature of my channel. 73, Doug

[@DJGeorgetheoriginal]

Good information, seen all the videos you made on this antenna. Question, how many watts will this antenna handle in digital modes (ft8) thanks.

[@n4hnhradio]

The official rating from Yaesu is 120W A3J/J3E (SSB). So it should handle the maximum of 50W that Yaesu recommends for FT8/4.

[@jasonbrown5265]

Ever thought about mounting it in the roof to the mag mount and testing it then?

[@n4hnhradio]

No. I know better. It needs more than capacitive coupling to the body, for counterpoise. I think I pointed that out in one of the videos in this series. Also, I don’t want to put a $400 antenna in harms way. It might get torn up by a low hanging tree limb. That already happened to two of my ham sticks.

[@jasonbrown5265]

@@n4hnhradio I’m sorry if I offended. I meant just using it stationary, not driving around. To see if the car roof gave better performance My apologies for not clarifying.

[@n4hnhradio]

I wasn’t offended. I was just explaining that I knew better than to try the magnetic mount. The magnet doesn’t provide adequate coupling to the vehicle body, for counterpoise. Remember that the ATAS-120A, or just about any mobile HF antenna, is only half of the antenna. The other half is the vehicle body. My magnetic mount was always a compromise. Not because I wasn’t willing to drill a hole in the roof, but because of the stability needed to support a 6-7 ft. Ham Stick on the roof. The triple magnet provides the stability, but it doesn’t provide the direct bond of the shield to the vehicle body. The counterpoise is therefore compromised. This adversely affects the SWR/performance, especially at the lower frequencies. I had to use an ATU even with the Ham Sticks. For example, the lack of direct coupling limited the useable SWR range of my 40m Ham Stick to around 40kHz. And even with that, the lowest SWR achieved without the FC-50 was 1.5:1. People who use an ATAS-120A often report that they had to install numerous grounding straps to the frame, even when they install with a direct bond of the shield to the vehicle. The bond needs to get to the frame. I haven’t had that issue with my mount. My bracket connects to an existing bolt that has a good connection to the frame.

[@jasonbrown5265]

@@n4hnhradio Thank you for the help. Sincerely! I am planning on buying the antenna with an FT-891. My idea was to use it with a mag mount stationary, not driving around. I thought that would work better. I am a newbie to HF. I have been doing UHF/VHF for about six years and getting ready to venture into HF. I live in an apartment so that is not an option so a mobile set up is what I’m going to be doing. Just trying to figure out the best compromise. I truly appreciate your help. kg7bgm

[@n4hnhradio]

You might be okay with a magnetic mount for the higher frequencies. Even my 10 and 17m Ham Sticks worked okay with the magnetic mount. As I have said before, the lower frequencies are less forgiving when it comes to counterpoise. You could connect a ground strap to the frame of the vehicle to improve the counterpoise while operating. Why not consider mounting it like I did? Sure, my signal isn’t a perfect circular pattern. I have a stronger signal toward the front left of my vehicle, as expected, since the antenna is mounted on the front left fender. It represents approximately 2 S-units difference versus the signal from/to the right rear, and 1 S-unit difference versus the signal from/to the left and right of the vehicle. That’s okay. I can aim my truck. One of the S9 (VIP) members who helps bring these videos to you is a prolific POTA activator. He uses an FT-891 and an ATAS-120A mounted on the front left fender. He turns the truck to favor a specific direction.

[@Sky1]

wish that radio did 2 and 70 cm

[@n4hnhradio]

I prefer a separate radio for 2 and 70, so I can monitor one while talking on the other. So, this doesn’t bother me. My ICOM handles the 2m/70cm role.

[@AK4PJ]

I had read somewhere on the Atas120 that it automatically switches internally to CW and low power even though the rig doesn't show that. That lowers the power and throws a carrier.. Not sure accurate that is but I remember reading it somewhere..

[@n4hnhradio]

It makes sense to use CW.