Essential Things to Consider Before Buying an ATU 

Been a ham since 1979 and never owned a tuner. Thanks Callum!

Glad I watched this video! I never understood why people always said the 80m band was “so big”. The 300khz bandwidth is smaller than the 350khz bandwidth we have on 20m, what gives? It never occurred to me it was the percentage not the raw bandwidth that was the issue for tuning. Makes perfect sense now. Thanks Callum!

I went to a HWEF just the get rid of the ATU on my FT 818. Thanks for all the common sense.

I tune my system: 1 coax with dummy load. 2 antenna. I have been able to hit stations 400 km away using 2 meters with an SWR 1.1. It even makes receiving better! I hand made my antenna.

I think anyone setting up will look at a kit of parts and say yeah I need one of those without actually knowing why. Good to know why we need and don't always need some bits of kit.

Well, not Fred in Texas but Fred in Oregon. I am Not a Ham but an SWL, however I mostly listen to the Ham bands. My antenna is a home built fan dipole for 20M, 40M and 80M. I used to have a vertical antenna as well but during a winter storm it broke in half and I never got around to replacing it. I really like your videos. They are very informative.

Well articulated Callum

Edifying information as always thanks for what you do sir.

Thanks for all of your videos, I especially like these little snippets of information. It is always a pleasure to watch/listen to you talk about radio stuff that I find really relevant to me especially about the mic shy stuff. Keep it up you are doing great. Geoff, VK4NIX.

Makes sense get your antenna right and you won’t have to worry good stuff as always Callum cheers W9US

Great video quality and content! Much appreciated

Great as always! I am now a subscriber. Many thanks. I am moving from 1 to 2 antennas. My end fed non-resonant wire with 9:1 unun can be tuned to all bands, 160 through 6 meters with an internal modern rig tuner. So convenient! I jump bands all the time. I only use the ATU when I run the amp, which is not often. For single bands, I am using a tuned antenna which often works better on that band than the end fed non-resonant wire, but i can't jump bands without switching out antennas. Great to have the choice. 73, N7RLV

Well said Calum

A friend recently put up a Nebula at his place. He runs a solid state amp and a tuner. He kept kicking the amp when running through the tuner and finally figured out he didn't need the tuner with the amp and the Nebula since he tuned the antenna elements when he put them up. He's happy. His amp is happy and the Nebula is happy. I'm happy too because my Classic is in transit right now. Thanks!! Jack K5FIT

Thank you very much for the great and truthful video loved it Joe in Northern Ireland

Thanks for this information

Agree with much of what you say, but... ATU / matching units have always been necessary for me, mainly because I have never had the space to fit a resonant antenna. (hoping that a "bent around corners" end fed half wave may help) So I've always needed to use "compromise antennas" A good external match box is a huge help in such situations. It also highlights that many internal tuners don't have the range to tune short wires, or such like. They do as other comment's have said often give up around 3:1 Andy

Love love this!

It's not just because of tuning, but also no need to switch antenna's when going from one band to another which makes this lovable product 🙂

Great thoughts on ATU's and their spot in the big picture of Amateur radio.

What kind of impedance will have a fan dipole that covers i.e. 3 parts of 80m bands? 3 sets of wires: one tuned to CW part 3.550, one for the middle 3.650, and one for the top 3.750

Great video as always Cal. So I have been away week in Cornwall (Charlestown) - what a wonderful place that is. Returned home to Berkshire today and noted that my DX Commander has sagged a little in the heat. So taken down, adjusted and back up this evening. Just been testing with a CAA-500 and the performance is impressive as I expected. I can get the whole of 40m in SWR 1.2, and the whole of 20M in SWR 2 (with the bit I want at 1.2 SWR, and the rest where about I want it). As your table shows, can get a little hung up on SWR, I know I did in my CB days decades ago. But as your table shows, the losses at reasonable SWR are negligible. Also, as a new Ham (2E0MSR), I used to think the tuner was the magic bullet that could tune any antenna to give you want you want. But my understanding now is that all it does is present a good situation (50 omhs ish) to the radio. So with a brilliant tuner you could tune a coat hanger but the efficiency would be somewhat lacking ! Anyway - keep this coming Cal, great resource. Mark.

Very interesting video! Thank ND4A

Callum, I had to look up what it meant when I first saw your painted nail. This is what I found. Since the start of October (2016), men around the world have been painting one fingernail to join the Polished Man movement and raise awareness about physical and sexual violence against children. ### Keep rocking it mate. ###

Absolutely correct....!!!!!

Love it!

Yep, thumbs up from me. Been h.f. since 1976 and very successfully used a roller coaster and variable capacitor on long wires. Went QRP some 30 years ago. Now having a motorbike only and FT817 for portable use as it's smaller than my h/b rig and luckily another amateur gave me his MFJ16010 atu which he said didn't work. I used it for 2 years before it gave up. Investigating inside I could see nothing wrong until I poked around and found a wire had not been soldered but looked as though it was touching. I soldered it and no problem. I now have an outside inverted vee for 60m with dipoles in the attic for 20m to 10m. G4GHB

Great food for thought Cal. As a foundation operator with a measly 10 watts, losses from poor SWR really add up! (starting standard licence study this weekend! 100 watts here I come!)

Thank you Callum!!!! I'm going to share this one for sure. To many people think awe just throw a tuner on it and you'll be fine! I beat my head against a wall with these people. I tuned antenna will give you the power out you need. Putting a tuner in the equation, and tuning that 20m ham stick on the roof with a XXXX tuner and I can go 160 to 10!! Yea but for 99 percent of those bands you may as well take a bullhorn outside and scream CQ into that. You'll get almost as far as that band showing a 30:1 or worst!!!! Why people can not just take some time and build an antenna that works. Yes some are better than other. I have never Bought (With one $30 exception so I could learn about UnUns) an antenna I build my own. I with the help of friends when I first got started built a bunch of screwdriver antennas for our cars. Learned a hell of a lot from that build. I've made antennas that by all right should have just caught fire the first time I put out a watt or two, and they were fantastic. A lot of the bought antennas, take a heck of a lot of tinkering to get them anywhere near close to working. When I teach a course, Every one leaves with an antenna that will work Multi-band. (Fan Dipole.) By the time they leave they not only built there first antenna, but they get to see it work. Test it.

My IC7300 will match 3:1 not much more. My TS890 will do 10:1 with no issues, problem is I live in a neighborhood and my only choice because of lot size is a fan dipole which is good from 1.5:1 to 5:1 across all of the bands I operate. My solution was to run one ATU into one amplifier and be nice to both of my radios whatever I am running at the time. I agree with you most of the time unnecessary but with all the jumping around it protects against brain fade. Keep up the good work. 73

Thats a nice shade of purple Callum.... nine more to go. :) Good practical info again.👍

One correction. Most modern radio "tuners" are good to about 3:1. Really appreciate your take on this Callum. You do a great job breaking this stuff down so that it is easy to understand. - KI8R

I’ve been trying to find out if I need a tuner. This is exactly the video I’ve been looking for. I’m a new ham just bought my mobile radio, power supply, antenna and coax and not sure if I’ll ruin my equipment not having a tuner and a swr meter.

I can teach you about nail polish haha. I'm using it for toroids ))) This is great info that I didn't know about. Talking about bandwidth. I'm sure I read about it... but never really paid attention to detail. So this just ringed a bell when is about building antennas. Thank you for this. 73

In the short time ive been licenced and for many years on freebands, my take is a Resonant Antenna should be your first port of call over an Atu. Do the job right first time may help reduce unnecessary costs in the long run. Just my take and opinion. 73 Callum, keep up the good work.

I run the classic at home, no ATU needed with exception of the top end of the 80m band and that is only because I cut the antenna to be resonant on 3.8 mostly since I spend a lot of time down there. ATU just cleans up the top portion of the band and makes me feel better only. Otherwise, things are just as you explained Cal! Cheers and 73, KJ7FEE

When I first got into radio back in the mid-70s, we all had vacuum tube transmitters which meant the tank circuits had pi networks, also known as antenna tuners. Now in the age of solid state finals, we can no longer get away with the same antennas we had 50 years ago in many cases. Needless to say having a tuner either internal or external is a necessity in my book, unless you always have a resonant antenna or one that is very close to that as you point out in the video. Some of us and I include myself and maybe a small handful of others, go with non-resident antennas such as a doublet to leverage various advantages in the layout of these antennas. I'll add this thought: Locate the tuner be as close to the antenna as possible. I am absolutely certain that most hams, especially new operators, don't realize the coax between the radio and the antenna is in fact part of the antenna. Unless common mode chokes are strategically placed along the coax the feed line is part of the antenna. I won't go into all the problems that can cause but suffice it to say I would rather have the maximum power transfer from the radio to the coax and from the coax to the antenna. Aside from using a resonant antenna, the only other way to do that is to put a matching network at the feed point. Even what I'm saying would not satisfy a purist I'm sure, but in my humble opinion, if we're going to spend money on a tuner to sit next to the radio why not invest in a remote tuner to put at the base of a non-resident antenna? However, using your DX Commander vertical addresses that concern entirely. I do not have your antenna but I admire the engineering and the very reason why you developed it. Good show old man.

I started out on HF with a 17' vertical with a coil at the bottom and jumper I had to go outside and move every time I changed bands (PITA) and it got me on 10 - 10 meters. My Elmer said a vertical would be very noisy since I lived right by an Interstate highway. It was a little high but not bad and I could reach Western Europe, Australia, South America, and Asia from Oregon, USA. I then got an LDG-100 remote tuner and left it tuned for 40 meters, and it worked okay and I didn't have to trudge outside to switch bands. I finally got a 50 foot tower with a Hex beam (20, 17, 15, 12, 10 meters) so I get some gain and some side/back signal attenuation...AND NO TUNING NEEDED! Woo-hoo! I changed the length of my vertical (slide joints) to make it a dedicated 6 meter antenna, and again no tuning. To fill out the upper bands I use an Icom remote tuner so my transmission line losses are minimal to get 80-10 meters with simple in-the-shack tuning button. I agree tuned antennas are the cat's meow, but there are fully acceptable alternatives that work too (like your compromise on 80 meters. Nice video and thanks for your putting out this info.

I run a Palstar AT2K into a 160 loop. The swr is horrible on some bands, but I just force it until the 4 to 1 balun tells me it is pissed. I just don't want to run many resonant antennas. Tune it and run it. I get what I get.

I run manual antenna tuners for a few reasons. The most obvious is, I run solid state amplifier which requires it! Also, my Yaesu 5000 MP is a top notch rig, but its ATU range is the same as my 450d, which is only 3:1 or less. Also, I use your competitor's Hustler BTV6 with a very strong field of radials over very conductive soil. 40 meters will not tune higher than ~7.12 mHz. Trying to talk phone on the higher end of the US 40 meter around 7.25 or higher is a stretch for my radio's ATU. A seeming weakness of the Hustler, if used with good radial field. How does your product fair in this regard? Also, a compromise vertical like the Hustler has even narrower bandwith on 80/75. Doing the General class phone band of 200 mHz takes enough tuning as to need a higher capacity tuner to reach the extreme ends. Again, how well does the DX Commander do in this regard?

myself i use a EA 80m sloper not trimmed for a particular part just its full ength out of the box and for ft8 on 3.573 it tunes with my onboard atu on my ic 7610 @ approx 1 to 1.3 @ 100w using M&P ultraflex 10 and M&P compression plugs quite ok in fact @ 100w i can get into CN87 (Kitsnap County Washington) @ 4,521 miles with a acceptable signal report both ways, whereas my ultrabeam for 40-6m i have a flat swr as it is a auto tune antenna for any freq i am on, i do use M&P coax and plugs throughout though, the new M&P compression plugs over standard pl259s i am seeing maybe 1 or 2 more S points on recieve and conversly on Tx

Hi Cal, so if you wanted all of 80 could you build a multi-element vertical with 2 elements for the one band? Or a fan dipole with two elements for the one band? 73, VK7IAN

yes!

I have an ATU with built in cross needle SWR meter, most of the time it's switched out. I use the ATU on 80 and the top end of 10 and that's it. Do your toes match your fingers? Nice nail varnish!

A good manual impedance matcher can get some antennae to play nice that an auto cannot.

The power loss chart question. Isn't loss going to be dependent on the type of coax used and length of the feed? Or is this just a situation of "in the main".. meaning some kind of ballpark idea of losses. If so, I completely understand this wasn't for exact losses.

If swr is a direct measurement to loss, can you explain why most of the power is radiated by the antenna when feeding a dipole with 600 ohm open wire into a tuner with 10.1 swr and not 70%loss as those swr loss charts have us believe

I'm just too cheap to buy decent coax. I run an old AT-200 manual ATU through a home made 1:1 balun into window line to an inverted V of a convenient length. I wish I had a good place to put a DX commander where the cattle wouldn't tear it down, but my junk antenna works for now lol.

your nail varnish, matches your acoustic panels, how very colour coordinated M0IUQ

Interesting chart. The SWR on my open wire line 1m long to ATU is 1074:1 . I must be getting about 1mW of 10w power to the antenna? Or when I use a 1/2 wl of ladder line to a 50ohm antenna(multi band 40m dipole) Im losing 64% of my power at 9:1 SWR?

I think my on-board ATU will handle most of my mis-matches, and a BalUn Will work with most of what I put up. 73, Cal. WW5MB

I like Purple, not sure about Nail Varnish though 🙂

My radio tunes everything across the bands with my DXC with the exception of 10m and that’s purely because of how giant the band is. I believe even that would be better but I made my 10m element a little short.

That table at 5:20 is a reality check. 2.6:1 results in 20% loss, which is roughly 1dB... That is 1/6 of an S-point... I know - you will say 'Hey, every dB counts!', which of course is true. But I just want to point out that we sometimes go fussy about an SWR of 1.7:1...

I'm thinking of putting your antenna on top of a 3 meter tall stump about 50cm wide. Could I let the radials hang or instead, can I put a sheet of copper as a ground plane that theoretically could be smaller and perhaps more efficient than the dangling wires? I can use the surrounding roof and trees for guy wires but not a bunch of wife angering radials.(I would make a dovecote on top of the stump to sell the idea) Is this a naive idea?

I built my own ATU out of scrap bin parts so I could use my resonant at 40m antenna on 80m.

way hey DX commander goes all punk on us 🤣

My inductance switches arc when increase power to 100 watts.

Ok serious question this time… So after using an ATU an antenna that’s normally 6:1 still only yields half power? WY7WL

One day I would like to get my radio licence .I picked up a beat up uniden HR 2510 with an old antron 99 and a Wilson 1000 magnet mount .And a sadedlta echo microphone .The original microphone is missing for the radio .and 109 feet of the Heavy RG6 and a 10 amp power supply and some radio shack power/swr meter and a 100 Watt dummy load .It belonged to an elderly man and the nephews were selling off his estate ..paid a whole $50 for it .I have yet to set it up some where .It does power up and it puts out 25 watts on ssb ..I think it needs a new molex connector for the speaker and CW .Have to figure out what to do .There was more stuff in bins but I diddnt have the time to go through it was on my way to a service call on a saturday .Who knows what these boys gave away !

I built a few fan verticals and enjoyed not having to fiddle with the tuner when I wanted to move bands, using multiband antennas its almost always a must though as there is a compromise somewhere, with some exceptions. Most equipment will tolerate 2:1 and even 3:1 in ham radio, that is fine, the losses are not that great. but in broadcast where I spend my time, almost everything has either a ATU, slugs and or transformers for our fixed frequency cuz a quarter wave vertical at 1mhz is ~300ft (~90m) and towers plus land for a radial system are a premium. a 2:1 SWR or even 1.5 can be devastating as we could see several thousand watts back down the coax into the transmitter. but its nice seeing 42KW forward and 7 watts coming back :-) - KN4MYB

If my antenna feed line has a 6:1 SWR before the antenna tuner. And the antenna tuner matches that for me so the radio sees a 1:1 SWR. I am still only getting ~50% of the power radiated at the antenna, right? Where does the rest of the power go? (which part will get hot?).

not sure this strategy would work on an end fed random wire... where it's not actually resonant on most bands... but yet tunable on most.

If you run resonant antennas you will learn how to trim and tune and you will get your signal out farther, a tuner is a good way to learn more about radio and can save your finals but nothing beats a resonant antenna for creating pileups

An atu is in my view something for the modern era of hoa wars, limited space and convenience. Don't have the space and don't feel like getting up and going out to change the links on your linked dipole? Just get an atu. Multiband antenna to work all bands while keeping the hoa karens off your back? Atu! But in the end, to each his own. BUT, not having an atu is NOT an excuse to not be able to use more than one band. I have a linked dipole, 80, 40,20 and 10, all sections resonant in the middel of the phone portions and my IC-729 works beautifully on all 4 those bands.

Wiggly waves are just like humans, they are looking for the easy way out. If you have a resonant antenna, the wiggly waves rush up the coax and are happy to jump off the end of the antenna into the big wide world. If the antenna is not resonant, you can help the wiggly waves with an ATU but some will get lost and end up as heat and few more will get lost with the extra connections. If the exit route and connections become too much for the wigglies, you would be better drawing an escape map for them to get out! LOL 🤣

It's too bad you can't use 75 meters, I am on most nights 1:00AM - 3:00AM UTC on 3.916 where we rag chew and play Trivia, other than that, I use the lower part of 80 3.500 since I'm a CW operator. 73 de AI5DD, cheers. Edit: I did have my tuner on COAX Direct and found I didn't need a tuner on 40 and 20 meters with my 80-10 EFHW that's up via a 35 foot military camo net mast in an inverted vee config, 132 feet of wire.

is an ATU just an antenna tuna?

Thank you for the lesson. I've been telling people this for sometime now. An ATU doesn't tune anything because the antenna was not changed!!!! All it does is lies to your radio to make it happy.

I use an 80 meter doublet so I'm pretty much forced to use an ATU. If you use an ATU properly they can be quite efficient. If you use one improperly, you can destroy your own signal in losses. I've lost count of how many hams I've heard arguing about them. The key to using an ATU correctly is understanding how they work and understanding the limitations of the antenna system you're trying to match with it. Trying to tune a 30 foot long dipole up on the 160 meter band is not going to work worth a damn no matter what tuner you try to use. You can't cheat the laws of physics. Let's say you run a yagi and the match is not so great on the end of the band. An ATU can correct this with very little loss and you can enjoy using your yagi where it normally wouldn't work due to the SWR protection circuit. In other words...on coax fed antenna's use the ATU to correct minor mismatches and on balanced feed you have to use them all the time. For coax fed antenna's it would be best to just tune the antenna flat for where you operate, but not all antenna's will cover an entire band with an acceptable match.

I use an atu but only because my antenna’s are fed with ladder line.

US 80m is 3.5-4.0.

Having a good quality tuner is very handy to have around. for a lot of reasons. But buying one of those over priced junk ones with crappy made in house parts is not worth it. You can make a better turner for less money with carefully chosen parts is better. A good quality tuner will last a lifetime.

I use primarily a long wire with a 49:1 transformer which has it's frequencies but as I mess with the configuration and wire length I use an ATU both to increase the bands that it will work with and to resolve any SWR problems created by unusual orientations. No science is used in these experiments - just me messing around. Life is too short not to have an experiment or two 🙂. 73 M7BLC

Your totally right Cal. As a fellow musician, you know an antenna is like a tuning fork. to get maximum efficiency an antenna has to be resonant. All the tuner does is absorb your very expensive Watts from your very expensive linear amplifier and convert it to heat. 😀

It’s better to have resonant antenna less losses. I run a hw doublet feed with 4” open spaced Toad Harbor feedline 12awg thru a dentron super tuner

15m should tune fine on a 40m dipole.

PLUS, SWR notwithstanding, all ATUs are lossy anyway!

I've never understood why anyone would WANT an antenna tuner Callum! Last I checked, the whole point of "radio" is to make contacts, preferably as far as possible too. That means you want a good resonant antenna, not one that needs a lot of tuning!?😎 I suppose there's a market for ATU's to "appliance operators" though eh?

Some newcomers would benefit if you say what "ATU" stands for.

life is too short for non-resonant antennas...

With higher swr you are risking that you will damage your pa in TRX. And most od us can live with less power in antena, but not with damaged pa :) As you said if antenna is resonan and Has swr celów 2:1 then atu is useless. In all other cases it's good to have it.

Sorry that I'm late to the party, but my two cents. ATU's are necessary for use of non resonant antennas as most know. An ATU essentially fools a transmitter to protect the overheating of power output transmitters, and failure of amplifier finals. The ATU gives the appearance of acceptable matching between a radio power output circuit and the antenna, but does nothing to compensate for antenna efficiency at a given frequency when the VSWR is greater than 2:1. Thus 100 watts of power is reduced proportionately to the amount of RF energy that's reflected back to the point of origin.

Does Higher SWR Lead to Lower Power Being Transmitted? Not always so dramatically. Believe it or not, 100 percent of the power is actually trans- mitted in both of the previous examples. In the first case, with a 50 Ω antenna, it’s easy to see how all the power is transferred to the antenna to be radiated since there are no reflections. In the second case, the 33 percent voltage reflection travels back down to the transmitter where it doesn’t stop but is re-reflected from the transmitter back toward the antenna along with the forward wave. The energy bounces back and forth inside the cable until it’s all radiated by the antenna for a lossless trans- mission line. An important point to realize is that with extremely low loss transmission line, no matter what the SWR, most of the power can get delivered to the antenna. www.arrl.org/files/file/Technology/tis/info/pdf/q1106037.pdf

Excellent, thanks. MM3SCO Gary