ATU-100 AUTOMATIC ANTENNA TUNER N7DDC REVIEW AND WARNING! IT SMOKED AND FAILED AFTER USE ON 6 METERS 

Don't complain about the smoke, think first and then transmit. Read the manual. use low power (5-10W) to tune, then switch to full power. If itt does not tune properly, do NOT use high power. By the way, your ICOM has a tuner interface connector that allows to automate the tuning process with low power. This interface works well with the ATU-100. If you know how to use a soldering iron upgrade yout ATU-100 ... Another thing to check are the 2 diodes in the ATU-100. A number of cases are know where the chinese factory used wrong components. If you have one of them, the tuner will work fine on the lower bands, but not on 15m or above. Replacing the diodes with BAT41 solves this issue.

I think you are only ment to tune at like 5-10 watts max and then when your tuned up then turn up the power...... or smoke will appear...... I thought all hams were aware of this!!!

Not false advertising at all. The manual page you showed for your antenna specifically states “manual tuner” for 6 meter band. Not auto tuner. The N7DDC is an auto tuner. You smoked the 6 meter portion of the tuner using it improperly.

Should NOT use more than about 5-10W for tuning. I know Chinese manuals are not the best ever - but it does make it pretty clear you do must not just dump full power into a wildly mismatched system. It seems you even surprised yourself at what power level you were using from time to time. Main defect seems to be external to the unit.

Anywhere to get a manual on how to use the single button version? The instructions I found only cover the 3 button version

Thank you! I was going to buy one, but I figured I would look for videos. You have saved me money.

Thank you for sharing. I was wondering about this economical ATU option, so your comments are valuable and appreciated. I notice that your antenna states specifically that it should be used with a *Manual* antenna tuner. Could the antenna design be difficult for an *Auto* ATU? I don't know why it might make a difference, but I was wondering if a very high-Q might make it hard for the automatic tuner to find the the ideal tune without passing it by.

Looks like you are tuning with 38 Watts.. Thats your problem. You blew it!

This is actually a great little auto tuner…if you use it properly…which you failed to do. 1) Never, ever, tune with more than 5W power. 2) Don’t redline the performance when you operate at the fringe of the unit’s design capacity, it’s already maxed. 3) Read the directions before you hook something up and slam enough power into it to reanimate a corpse. Treat your equipment right and it will work properly, abuse your equipment and it will fail every single time.

Kevin Loughin's video of an assembled unit shows incredibly poor assembly, especially the grounding around the SO-239 connectors. This might be the cause of excessive VSWR on 6. 73's, N2GX

I have the same version with the green tuning knob. Does your tuner support tuning just by pressing ptt or does your one also slways need the green button to be pushed?

I think you should not be using more than 10W when doing the tuning, bad match in antenna - too much power - edge of working frequency = maybe the reason device is fried

Thanks for the video. Mine behaves funny too. Did yours make the 6 meter RX noise before you let the smoke out?

pass under warranty ? Or scrap it... I'd like to see what was burned and where the smoke came from...

The owners manual said to tune under 10 watts.

never had this problem, "YET" but thanks for the heads up keith i've programmed 50mhz to max out at 25 watts, but i do know the hf360 "sucks and blows as you put it" lol, apart from that, these tuners are ace for portable work, i use a usb powerbank with a little LED metre to keep it topped up as a flat battery can only cause some of the problems like this, 👍 de m1dls (ps bypass the unun on the 360 with any type of s0239 attached to the metal bit for the plus kit fitting, adjust antenna to 5m in total length to make a killer 20m vertical with a few radials,) then let the atu-100 do its magic i get 80-thru to 6m with no noise now, the hf360 6:1 unun is totally deaf, use two feed points to an antenna switch to compare, let the atu-100 become the matcher ... hope this helps 👍📡

Mine has the high 6M noise floor as well and I never let any smoke out. It also mostly doesn't match well, sometimes not at all whereas the tuner in the radio just behind it has no problem on the same antenna system. I am going to make a new controller for it and see what I can do.

A 1.7:1 SWR is NOT a problem - there is no need to use a tuner at all in this case! Secondly, you shouldn't use more than a few Watts to tune. RTFM reduces PEBKAC. "SWRs"? The R means "ratio" and there's only one of them... 73 KG5...

I have the 2 of the same units identical one in home 1 in truck and it works gangbusters on 6m.. Maybe its just faulty!

I understand you are supposed to tune with low power and then you can turn up the power for transmitting. My question is if the device is set to auto tune and you switch frequencies and the swr has changed enough to cause another retune it would be at the increased power level. I am going to look and see if there is a cell in the firmware to not allow tuning over a preset power level.

mine has bad digital noise on 160m and tuning below 30m band garbles the display

I'm perplexed...the N7DDC ATU-100's were designed, and all are (that I have and have seen) are all 1.8 to 30mhz (HF). I would almost bet a cup of coffee to a doughnut that it was misprinted. I've not seen anything in the technical literature about them extending to 55 MHz.

Hi, I also have build the ATU-100 and can not use it on 6m, it shows poor SWR. on all other FH bands it works fine, I use 5w max as tuning power, which is more than enough. For your information, I have bought is al DIY kit, firmware version v3.2. I have soldered SMA connectors on the PCB, and use UHF female bulkhead SO239 to SMA male RA RF coax cable adapters RG174. If some one has a hint or a clou for me how to get it to work on 6m (50mHz) i would be please. My opinion it is Most likely related to the design. So 6m capability may be to optimistic. 73, Frans (PA5CA)

Tune between 5 and 10 watts like any other tuner once tuned turn your power up

Would have been useful if you had shopwn the actual failure mode on the board and your steps to diagnose/repair.

All very interesting!!👈

I have that antenna, get an LDG ATU for this antenna and Super X Coax or RG213 not RG58, I also have this ATU 100 and it does this on 40m for me goes off RFi maybe not sure, I'm going open it see what it look like inside and none solder joins been known to have this problem too.

You have a faulty unit. I bought the kit and built mine and it works a dream on all bands including 6M band even at 100W. There is a major fault with your unit turned off and when you PTT it turns on. Get a refund.

Hello. Do you recommend this device? Is it a good device?

this device is only hf not 6 none of them did 6 meters well

Maybe it's your antenna? All tuners have quirks that change with the type of antenna they are connected to.

This is a Chinese copy with some cheap charger. N7ddc made a great tuner and Chinese made a cheap copy of it to make some quick bucks.

Warning ! You should to be able to change bad chinese RF capacitors if you want to use this device successfully.

It measures input power incorretly. Im using ATU qrp edition. and it shows me 3.3w > 2.5 out and other power meter shows 5w. so I wouldnt trust this measurements.

Why would you tune with 25 watts or more !???? You should ONLY ever tune with 5 watts ! No wonder you saw smoke come out of the charging port. Why would you think it's okay to use the tuner with more than five watts to tune? After it tunes, and it'll tune better on low power, then you can run a hundred Watts through it and it'll be fine

I think you should update your video title. It looks like you got a faulty unit rather than the design is faulty.

6m relay stuck i only trust manual tuners

The tuner is now dead after another smoke show on 6 meters!

Bad capacitor

Usual Chinese lack of attention to detail and EMC.

Fake tuner

Usual Chinese lack of attention to detail and EMC.