MFJ - 986 vs MFJ - 989D

[N5YPJ]

I've narrowed my search for a tuner down to the MFJ - 986 or the MFJ-989D and am looking for any input anyone might have in helping me to make a final decision. Yep I know there's some folks who don't like MFJ and have their reasons, but this is what my budget allows for plus I've used MFJ tuners for over 20 years so not much would surprise me.

I operate 100 watts, with an outboard tuner balun for using ladder line. Antennas I'd want to use the tuner on would be dipole and cox fed inverted L.

Any help appreciated.

[K8JD]

If you are using coax fed antennas, you don't need any balun in your tuner.

I have always used coax fed antennas in the past but just decided to try a ladder line fed double Zepp antenna for a few bands so I bought the new MFJ tuner that is specifically designed for ladder line/balanced antenna systems. Seems to be better Quality than my 300 W Versa-tuner.
I Will try to get up a 70 or 90 ft Zepp wire up between thunderstorms ...soon I hope.








zepp

[KJ3N]

I operate 100 watts, with an outboard tuner balun for using ladder line. Antennas I'd want to use the tuner on would be dipole and cox fed inverted L.

If you only run 100 watts, why would you buy a legal limit plus tuner? I would think an MFJ-949E would suffice. Are you planning on an amp?

[N5YPJ]

I hope to be able to run both coax and ladder line fed dipoles as I did before, I really wish I could find a wide range tuner without a balun as most of what's in the tuners are a farce that's why I chose to use an outboard balun outside the shack.

I work mostly digital with an occasional phone contact, one day if finances allow I'd like to add an amp but that's an if. For now I'd just like a decent tuner with a roller inductor versus a tapped inductor.

[N0AZZ]

Is the Ameritron ATR-30 out of the question it's still made by MFJ but I hear much higher quality?

[KA4DPO]

There are several schools of thought on this, here's mine. Always buy/use the bigest tuner you can afford. A legal limit tuner has larger components and less internal (insertion) loss than a cheaper smaller tuner. Also, you may want to get an amplifier some day and if you do your tuner will handle it. Lastly, get a tuner that can tune coax, random wires, and balanced feedlines. That way you can experiment with a wide variety of antennas and again your tuner will be up to the task without arcing and sparking.

If you can't afford a brand new one don't forget there are plenty of good used legal limit tuners out there on Ebay, QRZ, ARRL, and Eham just to name a few.

That's my two cents on tuners.

[WB2WIK]

There are several schools of thought on this, here's mine. Always buy/use the bigest tuner you can afford. A legal limit tuner has larger components and less internal (insertion) loss than a cheaper smaller tuner. Also, you may want to get an amplifier some day and if you do your tuner will handle it. Lastly, get a tuner that can tune coax, random wires, and balanced feedlines. That way you can experiment with a wide variety of antennas and again your tuner will be up to the task without arcing and sparking.

+1.

I sure agree with all of that. The less power you use, the bigger your tuner should be (less loss).

I've literally "blown up" everything Palstar makes, plus a Nye Viking MB-VA (rated "3000W") and some others, just using them normally but at high power. The Ameritron ATR-30 I've had for just over ten years now and never had any sort of problem with it. I'd pick up an old, used ATR-30 over a brand new MFJ anything.

Of course tuners are simple enough they can be homebrewed if you can find good components. Some GREAT components come out of surplus military and broadcast transmitters. A lot of military stuff is very underrated (e.g., typical 500W transmitter can often really do 1kW+) and have beefy components -- not all do, but many.

[W8JI]

I've narrowed my search for a tuner down to the MFJ - 986 or the MFJ-989D and am looking for any input anyone might have in helping me to make a final decision. Yep I know there's some folks who don't like MFJ and have their reasons, but this is what my budget allows for plus I've used MFJ tuners for over 20 years so not much would surprise me.

I operate 100 watts, with an outboard tuner balun for using ladder line. Antennas I'd want to use the tuner on would be dipole and cox fed inverted L.

Any help appreciated.

You want to avoid a differential T (the 986 or anything else using a differential T) if you like 160 or 80 and run high power. Even the PalStar very expensive automatic tuner that is a differential T has problems on 160 meters (and the PalStar has a balun that is not even a balun in that tuner).

If you PROPERLY learn to tune an older 989 it will be good to about 1000 watts or so PEP, maybe more, but I would call it a 1000 watt or 1200 watt tuner.

The 989D looks basically like an MFJ-built Ameritron ATR-30. So if everything is together correctly and if they used the same edge wound roller, it should be virtually identical. I am NOT sure if it uses the same edge wound roller inductor as the ATR30 or not. Check and see.

[WB5WSV]

Like some others here it seems at times that my real hobby is burning out antenna tuners; any communication that occurs is just a side effect.

I am using a homemade dipole in my attic with a balan and found that my MFJ-949E did pretty well, except on 80 meters where an SWR lower than 4 or so was very hard to obtain. I recently bought an MFJ-969 under the theory that without a coil switch there would be less for me to burn up.

The 969 is much trickier to tune up than the 949. You can find two spots where it will work that are close to one another in terms of settings, with one spot much better than the other, the Load control on my TS-520 being the determining factor. But MFJ provides recommended settings for each frequency range and this helped a great deal; I am not sure I would ever had found the right settings otherwise.

With the 949 you just turned the coil selector knob until you got the loudest static and went from there.

This morning I loaded up my antenna on 3.9 MHZ with a very high power output indicated and an SWR of 2.0, which is by far the best I have done on 80M.

I want to try a longwire in the attic next but need to wait until temps up there drop to less than a zillon degrees.

Good Luck!

[W8JI]

With the 949 you just turned the coil selector knob until you got the loudest static and went from there.

Years ago I rewrote the manuals to get rid of that tuning method. Tuning for maximum noise is a good way to blow up a tuner.

The more recent tuning instructions are the way to do it, no matter which tuner you have.

73 Tom