MFJ-939 Plug & Play IntelliTuner review.

[@SinfulZin]

Thanks for the demo and the explanation! I just got mine yesterday and I'm going through the same thing with trying to figure out which method will tune it up each time. I thought I might have received a bad unit, but now I see it just takes a little bit of trial and error sometimes. With that, I still find it amazingly fast and reliable and a very welcome replacement for my old manual tuner. I love this thing and I'm looking forward to future activations with it. I love how compact it is and it's nice to have a backup to my tuned field antennas. I really appreciate your honest videos that show some of the quirks of equipment sometimes. They let me know it's not just me.

[@roxyannpeak]

I had the 939 with my 891. It did ok. I had issues with it communicating with the radio from time to time. I ended up selling and picking up the mAT-30. I love this tuner, and I also get 6 meters!

[@RonanCantwell]

Ok, call me slow. I've followed your channel for ages and I've only just realised your start/end music is your callsign in Morse. I always thought it was a bit odd but never made the link... Keep up the good work. 👍

[@hamradiotube]

Haha thats awesome. I don't think too many people get that. Thats me playing guitar and yelling CQ. Recorded it at my buddies studio.

[@viknumbers701]

I have one and it really works very well and is fast.

[@barrygkx]

Nice review. The MFJ ATU's put all other's to shame. I use the 929 and it's great. The big advantage the 929 has over the 939 is, you can set the ATU not to stop tuning until it hits a perfect 1 to 1 SWR. If it's can't get there, it will stop at its lowest SWR. Also, you can set it to auto tune if the SWR hit an SWR level that you like. I set mine to ATU on its own if it sees an SWR of 1.7 to 1 or higher. So if I key the radio and the ATU sees a 1.8 to 1 SWR, I don't have to tell it to tune, it does in on its own. But for portable, I like to keep it simple and small. So the 939's size is perfect if an ATU is needed to work portable. Barry, KU3X

[@KX4UL]

Nice look at the tuner Mike. Thanks for the demo!

[@kennethblackwell1137]

I have both FT-891 and MFJ-993. This was very good for me. I had not learned how to use the MFJ-993....Thanks...!!

[@hamradiotube]

Awesome, glad it helped.

[@WJ6FRadio]

Another kick ass video!! Dig the size of this tuner!

[@hamradiotube]

Hey thanks. It's perfect for portable ops.

[@rondellschuyler7074]

Love that yaesu ft 891. Great combo

[@hamradiotube]

Its pretty awesome indeed.

[@CoHamGuy]

chiming in to say i get the same kind of behavior where you have to fiddle with it sometimes to get it to attempt to tune, it’s a little unsettling because you think it has a mind of its own. also a little lcd screen would be so nice to let you know what antenna memory set you’re on and other current state modes are actuve

[@k2cjbradio]

not a bad tuner. I’m thinking about adding one in my truck install to get a little more bw on 40. Not sure which one to pair up with the 7100. Thanks for the demo!

[@hamradiotube]

Thanks Chris. If you want one for the 7100 just get the model with an "I" for Icom.

[@pathtouch1]

Also when mine shipped the jumper inside wasn't set properly for Yaesu so definitely open it up and double check that. Other than than I love it, see my using it in one of my SOTA videos and during Winter Field Day this year.

[@hamradiotube]

I guess I'll have to open mine up and double check. Is there a marking on the jumper to show what radio goes where?

[@pathtouch1]

@@hamradiotube imgur.com/a/xPd75o7 check out those images. Jumper JP4 needs to be shorted, and JP2 should be set to Y. Apparently I have mine set to K and didn't even realize it. Whatever it was working, YOLO!

[@bentleys5059]

Curious, have you noticed much of a power drain? I see in the LDG specs, they mentioned close to nothing when not tuning. Not sure about the MFJ, but the 939 had a bit more power consumption listed - could not tell if that was just when tuning or aways when on. Appreciate your comments.

[@hamradiotube]

Just hooked it up to my Powerwerx watt meter and it shows 0.00 A being pulled on standby. I'm sure it takes a little more juice when tuning but once the relays do their thing it's set.

[@bentleys5059]

@@hamradiotube thanks for the reply, I'm close to pulling the trigger on one

[@MikeG-js1jt]

seems like you would have done a lot better with an extra 10 or 20 ft of wire?

[@ryankc9oza118]

I tried this tuner out against a tuner called mat 30 tuner. And the mat would tune any antenna I tried alot easier. So I put the mfj on my 7300 for now.

[@andrewhamop6665]

Question, when the 939 is connected to the radio via the interface cable, does the it automatically lower the power output of the radio when tuning so you don't blow up your PA? Would be quite annoying to have to do it manually.

[@hamradiotube]

Yes, I don't remember exactly but its less than 10 watts. It says somewhere in the manual. If you're into reading those before you see the magic smoke that is...

[@angpar8449]

Hello. Can I see that the interface cable is a j45 plug. Can the interface cable be extended? does the rj45 use traditional 568-a or b ethernet standard or is the wiring different?

[@bentleys5059]

Nice video, appreciate the info. What size battery is that on the bench?

[@hamradiotube]

Depending on how keen your eye is there are actually 2 batteries I had out there. The one I used is a 20AH Bioenno, but I had a 3AH Bioenno on the bench as well.

[@forgetyourlife]

Does the tuner lower the watts to 5 when tuning even if the 891 is set at 100w?

[@hamradiotube]

Depends on how you have it set up. But yes, it can.

[@jamescoffey5225]

You may get an OK SWR on 160 meters, but your antenna efficiency will not be good at all using the Pactenna Mini or any other short wire antenna. Also as you may have observed, you might get better performance using the shield of your coax as counterpoise without any other counterpoises attached. If you so desire, you can put your RF choke near the transceiver to block any potential common mode currents. I use 60ft of wire in L configuration attached to a 5:1 UNUN. SWR is better with no external counterpoises; only using 25-27 ft of coax's shield as a counterpoise. Your ultimate antenna performance under a specific configuration is dependent upon your location as I am sure you already know. Great video! 73 de AE5ZX

[@hamradiotube]

I spent a good deal of time trying different configurations yesterday when I was filming this. It worked really well when I placed it at the antenna feed point powered with a small Bioenno battery and a short 2 foot coax from the tuner to the antenna. I prob should have shot some of that. I understand a huge amount of power is going to be lost from the coax when trying to load up the top bands and that configuration would help to minimize that. The fact that it tuned 160 at all is pretty awesome. If I really needed to get on that band for some reason, I know I could. Even if only a watt or 2 actually went out the antenna. The length of the coax in general does matter with the antenna as well. I initially used a shorter 20ish foot run and it was absolutely horrible. This was about 50' of coax and it worked a lot better. Thanks for the comment and thanks for watching. 73

[@joewilson2258]

@@hamradiotube that is the best place for the tuner not at the radio end .

[@JnJTrueOutdoorAdventures]

Mike curious why you went with the MFJ versus the LDG auto tuner? I have the LDG Z817 (QRP version) for my Yaesu FT-817ND and I love that thing. Great video and it looks like that thing will tune just about anything!! 73 Juddie WD8WV

[@hamradiotube]

Simply because I have a great relationship with MFJ and they sent it to me.

[@ae1tpa92gwtom2]

thx Mike, what tuner were u usung previously,.. i have the LDG cousin of this one,, but frankly unhappy with it, and went bk to my 945E, looking to get a tuner for the house, n debating auto or manual. cheers n thx for yr videos,.. 73

[@hamradiotube]

I was using a little MFJ portable tuner. Worked great, I just wanted something that was quicker.

[@shawnp6653]

Nice video Mike - thanks for sharing w/ us! Do you know how many watts on digital modes it is rated for? I can't find that anywhere.

[@hamradiotube]

The manual states it is rated for 200 watts SSB/CW. Doesn't say anything about digital but usually digital and cw are lumped together in a power rating so I would guess you would be ok at 200 watts. Thats just a guess though.

[@alvarogaitan2529]

Great video mike thanks

[@nrnrnrify]

Does it tune also on receive? I mean after tuned to desired frq, does the RX go thru tuned relays? Or maybe tuning only works while TX? Im planning to buy my first HF radio, at first looked towards Yaesu FT-450D, but since I figured out most cheap radios have not so great tuners now I consider getting portable radio + good, external tuner.

[@hamradiotube]

Kind of. It's actually a lot easier to demonstrate on a manual tuner, where you change the inductance and capacitance, and listen for the most noise. That's when you know you are in the ballpark of a match. So in a way, yes, it does tune RX, but its primary goal is to make your radio think you are transmitting into a 50 ohm antenna. The term "Tuner" is really a bit misleading. It's really an impedance matching device. However, if you are on 40 meters, and want to listen to 20 meters, if you haven't tuned the tuner, the signals will be significantly weaker. I can't say for certain, but my guess would be yes, the signal goes in and out of the tuner from the same relays. My first HF rig was a Yaesu FT-450. I made a resonant 40/20 fan dipole and worked all over the world with it. I had a tuner to match other bands if I wanted to, with some success, but keep in mind, nothing will be more efficient than a resonant antenna. For example, with my 40/20 fan dipole, it will "tune" up 80 meters, even 160 for that matter, and make my radio happy. But the RF that was actually going out to the antenna was so little making contacts was not easy. Most of that power was lost to heat. This topic is such a vast one we could literally talk for days on it. The best advise I could give you is get a resonant antenna. Even though you may see videos of me using non resonant antennas out in the field with a tuner and is totally contradictory to what I just said. A tuner is not going to make the power go to your antenna. It only makes your radio think it is. Hope this helps more than it confuses. Let me know if you have any more questions though. 73

[@Kohflot]

Did you have to crack open the case of the tuner and adjust some jumpers to get the control cable to work? I don't see the 891 listed for that, but a lot of other radios apparently need it.

[@hamradiotube]

I did not. Plug and play.

[@Kohflot]

K8MRD RADIO STUFF Interesting. I wonder what makes the 891 different than the others!

[@hamradiotube]

@@Kohflot Not sure. I did have to do that with my signalink though. Pretty sure you can buy it 2 different ways though. One way just the tuner, the other with the tuner and a Y, I, or K after the model number to signify what radio brand and cable it will work with.

[@scottgies]

Mike, what tripod do you use for you wonder pole?

[@hamradiotube]

I dont use a tripod. I have 3 bits of mason line attached to it with a hose clamp to guy it.

[@forgetyourlife]

Finally back in stock last week. Mine came with a banana plug and a small metal slug thingy. What are those for?

[@hamradiotube]

The banana plug is for a long wire/random wire antenna that you can insert into the pl259. Attach a counterpoise to the ground screw and you got yourself an antenna. Not sure what the small metal slug thingy is. I don't remember getting one of those.

[@forgetyourlife]

K8MRD RADIO STUFF ah, thanks. I didn’t see that one coming. What a w-i-d-e tuner it must be.

[@hamradiotube]

@@forgetyourlife It should tune just about anything you throw at it.

[@forgetyourlife]

K8MRD RADIO STUFF After a month with this tuner it’s seems to shut off my mic quite often. I have the either unplug it from the 891 or power down then back up. Between that and the “wait” bs I’m moving on to something else.

[@hamradiotube]

forget_your_life hmmm that’s weird. I would guess some rfi may be getting into it. Have you tried putting a ferrite bead on the mic and or power cable?

[@Mr_Meowingtons]

i have this tuner with my FT-891 and my TS-2000 on my Doublet it works good! the only thing that makes me mad is when i am tuning around on the band it keeps saying "wait" over the VFO omg that drives me SO nuts! when i'm using it to fine tune some one in or go to a freq some one is on "wait" "wait" "wait" "wait"... and i have no clue why i have swapped the tuners over the TS2k makes the 939 tune longer? so it gets a flatter match every time.

[@hamradiotube]

Isn't that the worst thing in the world?! I feel it knows that patience is not my strongest quality and does it out of spite. It could literally do the exact thing in the background without the need to tell us to wait. And I love how it has to cover up the freq. Like, put it anywhere else, but nope.

[@forgetyourlife]

Yep, this should have been covered in the video. Minor issue maybe but happens all the time like a bad tooth.

[@jacknixon3352]

What antenna did you use?

[@hamradiotube]

In this video I have a 40 meter OCFD, but you can pretty much use any antenna you want. This will tune a wet noodle if you ask it too.

[@rondellschuyler7074]

Is it better to have zero Swr or say a 1.1 ? Thanks

[@hamradiotube]

The closer to 1.0:1 the better. 1.1:1 is darn near perfect. Honestly if its under 2.0:1 it's gonna be fine.

[@tx2sturgis]

Ground switch?

[@hamradiotube]

Not sure what you mean so I'll just say Station.

[@GunsandRadios]

I know your not a digital guy but how do you judge the power capability of the tuner running digital

[@hamradiotube]

The manufacture of the tuner will have the specs on that. This one is rated 200 watts SSB/CW, which would also include digital. Go by what the rating is for CW for digital.

[@GunsandRadios]

K8MRD RADIO STUFF thanks wasn’t sure if it was the same as CW or lower I’ll dig some more on MFJ’s site. 🤘

[@mikehamilton7206]

You didn’t Attach a ground to the antenna tuner.

[@hamradiotube]

I haven’t attached a ground to anything I have radio related.

[@thomashenderson603]

Would this work with a ftdx101d with the cable

[@hamradiotube]

Yes this will work with any radio.

[@TI2GBB]

this tuner works in 6m band? thanks 73s TI2GBB

[@hamradiotube]

It does not. It covers 160-10 meters.

[@jsieb]

"Nope, it still hates life..." LOL It'd be nice to see this head to head with the LDG..

[@hamradiotube]

Send me one and we'll do a shoot out.

[@Tarakian1999]

Having had both, the MFJ is a lot faster.

[@thomasstandley6309]

I also have both and agree with the other comment that the MFJ is faster.

[@barrykery1175]

Great little tuner. Yeh.....you're really pushing the envelope trying to get it to work on 160 meters. Hi Hi I have the MFJ 929 and it works great. But, to keep things compact for portable operating, the little 939 is a great choice. Thanks for posting and showing how easy it is to assemble the package, antenna included. Barry, KU3X

[@hamradiotube]

Hey it worked on 160. Of course thats pushing the envelope, but it did it. Most of your power is going to be lost to heat of course, but I have made 160 meter contacts with my 40 meter dipole. Wasn't using this tuner, I used my 949 I think it is?? Anyway, thanks for watching. 73

[@joewilson2258]

Any tuner does nothing but tells the radio is seeing a 50 ohm load but nothing else for the antenna and coax cable .

[@n8nkqrp595]

Great video and fun. I know you love the antenna and you should. But if someone wants to make their own, or make one who's efficiency is higher than that one.. use a multi tap unun. Yep- you'll have to get up from the chair op switch taps to work on 15 or 10. But for 40 and 20, same tap.. and you'll have an SWR under 1.3 to 1.5... if not 1:1... which means no tuner at all. No losses in said tuner to suffer. Plus, for the cost of the unun... $3.75... you'll have a better signal and have fun building the unun. I promise. I just did an EFHW comparison of my 6' high 40m EFHW and my 26' high inverted vee in the trees if interested. Plus, you'll be treated to a new 'I hate FT8' rant. 73 OM

[@ke6mt]

I have this autotuner. I like it quite a bit.

[@hamradiotube]

Thanks Rex. I'm still playing with counterpoise lengths but it seems to be working well enough so far.

[@JT-py9lv]

👍👍👍👍👍 Thanks

[@hamradiotube]

You're welcome.

[@scottbuttrick-w8skb396]

I have on and it works great! Better than LDG in my opinion.

[@hamradiotube]

I haven't used the LDG but good to know.

[@alvarogaitan2529]

thanksJaison nice review 73 from kb2uew

[@hamradiotube]

I'll be sure the thank Jason for you. I'll see him tomorrow. My name is Mike. Nice to meet you!

[@alvarogaitan2529]

Jejeje ok Mike jaison

[@davidsradioroom9678]

It will tune a radio, but will it tuna fish? 😁

[@hamradiotube]

You know, I almost did an intro referencing that.

[@davidsradioroom9678]

@@hamradiotube Hey, maybe we're both smart alecs!

[@TonyLing]

If I were a Mercan, I would hang my head in shame every time MFJ were mentioned

[@landonmiller6943]

LOL

[@hamradiotube]

I know they have a bad rap for a lot of stuff but their tuners are really good. I honestly haven't used much of their stuff that didn't work. There were a few portable antennas that I've tried out and had such bad luck I didn't even make a video on them. Sure there are other brands out there, but usually at a greater cost. Anyway, thanks for the comment and thanks for watching. 73

[@landonmiller6943]

@@hamradiotube I've had bad experiences with MFJ gear, things that just stopped working, I did buy their twin display wwv clock a year or so back and so far so good, it's working fine. I was in the market for an antenna tuner recently and went with an LDG instead of an MFJ. Glad your MFJ antenna tuner seems to work ok though. I would like one of those PackTennas but they seem to be permanently out of stock.

[@TonyLing]

@@hamradiotube I have the MFJ-969 and it works OK sort of. It creaks and groans when you twiddle things, but we have come to expect that from MFJ. The thing is, MFJ gear is overwhelmingly under inspiring, and totally joyless contraptons. They seem to understand adequately how to design a circuit, and then get someone in a shed to design and build it out of left over parts from the late 1970's Look at your Paktenna and its wonky knobs for instance. These are not cheap here in the UK and I would expect better for my money. Anyway, totally enjoyed your video, and I am a long time subscriber. Keep up the good work. G7TXU

[@hamradiotube]

@@TonyLing The PackTenna isn't from MFJ. Also doesn't have knobs. I imagine everything over there costs a bit more due to shipping so it might be a bit harder to swallow for sure.

[@orangeandslinky]

Man that tuner sucks.

[@hamradiotube]

Thanks for watching. Glad you enjoyed the video!