Manager


Manager - NA4M
Manager Notes

Reviews For: MFJ-998 IntelliTuner

Category: Antenna Tuners/Matching Networks

eMail Subscription

Registered users are allowed to subscribe to specific review topics and receive eMail notifications when new reviews are posted.
Review Summary For : MFJ-998 IntelliTuner
Reviews: 112MSRP: 699.95
Description:
The MFJ-998 Full Legal Limit 1500 Watt Intellituner takes you to the final level in automatic antenna tuners. With a capability of 1500 watts SSB and CW, coupled with automatic tuning, your high-power station can now operate essentially hands-free even when frequency and band changes are made.
Product is in production
More Info: http://www.mfjenterprises.com/products.php?prodid=MFJ-998
# last 180 days Avg. Rating last 180 days Total reviews Avg. overall rating
001123.8
N8WGM Rating: 2022-03-29
Quick and nice Time Owned: more than 12 months.
I've owned this tuner now for a few months and it never ceases to amaze me.

It tunes very quickly and allows me to operate on sections of bands my antenna is not resonant on. 1500 watt capacity is nice.

It is somewhat noisy the first time but once it gets the settings in memory, it is just one little click and it is tuned. The first time, it may click for a few seconds to maybe a minute. After that, just a quick click and boom....you are tuned.
It has 20,000 memories so it will remember pretty much everything you need to operate anywhere in the ham bands with the right antenna.

I recommend this tuner. I've owned many manual tuners and this is my first auto tuner. You don't know what you are missing by using an auto tuner.....it is a real nice change from a manual tuner.

Update 3/28/22
I got out of ham radio for a while and sold the MFJ 998. Recently I decided to ham it up again and so I was looking for a 998 as it is a great tuner. I found one and got it in 1 day shipped. They are rare right now due to the election infection and the supply chain nonsense.

I set it up and it is as good as I remember. I run less than 1200 watts so it covers everything nicely. It does help to have the radio hooked up to the tuner with a cat cable that allows the tuner to recognize the frequency automatically. Just a tap on the pedal on AM (amp off) and it goes right to the frequency and to the settings in memory. Glad I got another one. I would have gotten the Palstar HF auto but it is huge and it must be made of unobtanium. Palstar HF auto is on back order and so the MFJ 998 is a good option plus it saved me eight hundred dollars.
VE3EMA Rating: 2022-03-26
Doesn't Always Tune Between Bands Time Owned: 0 to 3 months.
I would give this a Four out Five as a "Manual" tuner but don't get this if you require a fully automatic tuner. Depending on the band last used, you may have to press the "Tune" button to tune and even then, it sometimes doesn't always work. Had to replace this wjth another manuafcture that auto tunes flawlessly between all bands.
W3ATT Rating: 2022-01-28
At first I didn't like it Time Owned: more than 12 months.
I had a problem at first where the tuner would sometimes not recognize the frequency that I was on, had to change bands, tune that one, then back to the band I wanted. Or- I would have to sit there while the tuner ran the algorithm over again to find a match. I HATED that! And I've seen other reviewers with the same issue. I was so frustrated with it, that I put it on the shelf for over 2 years only to come back to it to try again.

While messing around with it, I found that if I hit the TUNE button on my radio with 5 watts (no more) and push the tune button on the 998 tuner at the EXACT same time (no delay,) the tuner instantly reads the frequency and snaps into a match. (This, after doing a few sweeps up and down the band and finding/storing memory matches) Perfect! Now I'm hopping around the bands with ease!

I'm using an older Ten Tec Orion and do not have the tuner interfaced with the rig, only coax connecting the two.

If it's off a bit, I adjust the C-up/down and L-up/down and hold the mode button to enter the menu, and over write memory so it remembers those exact C and L settings for the next time.

I bought mine used and it works very well now that I've figured it out. I really wish it had a 3rd ant out so I could hook up my dummy load for amp tuning, but I can use an external switch.

Overall, I'm now extremely happy with the 998. I can tune in a snap and apply full legal limit from a Ten Tec Titan. No problems.

Mine has good solder joints, no blemishes, and the meter works fine, although the meter back light does NOT turn off when you power down the tuner with the power button. I guess it was meant to be switched on and off with a power supply? Any way, I am planning to put a separate switch to power off the meter light or some other mod which will grab power from the board to switch a small 12v relay inserted in the backlight circuit.

Note: the meter is not a "peak-hold" meter as is described in the manual.. I contacted MFJ and they said it's a feature which has not yet been added? Weird, but maybe a firmware update in the distant future?
N2OTY Rating: 2021-06-04
Good Legal Limit Auto tuner Time Owned: more than 12 months.
So my HF setup that incorporates the MFJ998 is a Yaesu FTDX3000 into an ALS1306 solid state 1.2kw amplifier, being fed through the MFJ998 tuner to my 80 meter full wave loop, an end fed 148' long wire or an Antron-99 that I have up just for fun. Over 90% of my use is with the 80m full wave loop. I have been using this setup with the MFH998 tuner for a little over three years.

While I can truthfully say this tuner has never let me down, it has not been without some frustration.

Before this tuner I had an old manual Dentron Super Tuner. It was great, easy to use, bullet proof, painfully slow. the MFJ998 is lightning fast, sometimes it is so fast I don't think it worked, but it remembers the frequencies you use and tunes very fast (like instant) on frequencies you use a lot.

I do get errors on occasion. I usually get one of two errors. The first error I get is "Not Enough Power" this error usually occurs when I change bands and attempt to tune. The other error reports the SWR is over 25:1 and both needles on the meter swing around.

So the first error "Not Enough Power" the tuner requires a minimum amount of power to run a tune cycle, I think around 10or 15 watts. My radio automatically disengages the amp and sends low power to the tuner to initiate a tune cycle. So if my radio output is 60 watts, when I run a tune cycle the tuner always gets 20 watts. If I stay in one band I can move up and down the band and re-tune occasionally as I move to different frequencies and it will tune reliably with a successful match. When I change bands, occasionally I get the "Not Enough Power" error. Sometimes trying to re-tune will be successful, sometimes it will not. If I turn the tuner off and back on this almost always resolves the problem and it will tune fine once again.

The other error, the "25:1 SWR" error where the meter needles swing around usually means I have to turn the tuner off and back on again. It will almost never recover from this error with out a restart. I have only experienced this error when I am switching bands. After a restart it tunes as expected in bands the antennas are designed for.

Now, while it is inconvenient to have to restart the tuner occasionally to get it to perform the way it is supposed to, and I should not have to do so, it is still a lot faster than the old Dentron Super Tuner I used to use.

So in summary, I do like the tuner. I would say about 85% of the time it works as it is supposed to, I change bands a lot and that is where I tend to see the issues. I consider these issues minor. I would still recommend the MFJ998. It's not perfect, but it is a good legal limit auto tuner that does what it says it does. Does it need a little coaxing now and again? Yes. Should it? No.

I will continue to experiment with feed power levels and settings to see if I can find a resolution to these issues. If I do discover anything useful I will update this review.
K7HN Rating: 2021-04-15
MFJ 998 Works Like A Charm 24 + Months And Counting! Time Owned: more than 12 months.
I’ve had this tuner about two years. Every time, reliably tunes wherever I need it to.

I’ve found its robust menu system to be easy to navigate and, knock on wood, it’s never let me down once.

I highly recommend this tuner Just someone looking for a QRO tuner. It just works like a dream.

73’s and all the best,

Larry
de K7HN
YouTube: Ham Radio Live!
N0SQ Rating: 2021-04-03
dummy load Time Owned: more than 12 months.
One feature that would have been nice is to have a third coax output to route the RF to an external dummy load. This is a possible mod by installing another coax port and a switch to route the RF to that coax port - something to try after the warranty period.
I used it with an amp for a short time and it worked fine.

----------------------
Earlier 4-star review posted by N0SQ on 2017-04-21

I just got this thing yesterday. The only problems that I have with this tuner is that there is no avg/peak pushbutton for the cross needles like my manual tuners have and that my USB serial port cable won't plug into the MFJ serial port due to a mounting "ear" issue. Plus the JP1 strap wasn't installed even though the default is to have the strap installed (according to the manual). Another issue is that the manual says that the display is suppose to show the firmware version when pushing and holding the TUNE and then Power buttons but it turns out that I had to hold the buttons in until the "NO INTERFACE PIC" message disappeared. MFJ tech support said that "NO INTERFACE PIC" message isn't suppose to show up on this model but it isn't causing any problems, so far, so I'll live with it. A factory reset didn't clear that message. Anyway, I bought the Kenwood interface cable which made this a slicker arrangement. Too bad the tuner doesn't do 6 meters (which my TS2000 is capable of doing). Other than that it works great. I haven't tried it with an amplifier since I don't have one right now. I'll probably try some of the other features as time goes by.
W7SJ Rating: 2020-09-24
Tricky device, some design flaws, beware! Time Owned: 0 to 3 months.
I just took delivery yesterday. Spent ALL day trying to get it to work. Ran into the infamous power meter not working over ~200 Watts. But I solved that !

I was perplexed on how it was that the meter(s) analog and digital are able to work up to ~200 Watts, but not beyond. Sometime you can get it to kick in, sometimes not.

Amp is a Ameritron AL-82. Here's what I found :
IF you start transmitting in SSB, at power, the meters DO work. Switch to CW, and it won't work - power meters are dead, sometimes they work.

So, I tried this: start transmitting in SSB, and then w/o letting go of PTT on the radio, simply switch to mode: CW. Wella! - the power meter springs back to life each and every time.

Fast forward a whole bunch of electronics troubleshooting, I concluded that it's the way that the AMP (AL-82) switches it's T/R relay, vs. the "timing" of the actual RF power coming down the pike into the tuner.

Radio is a Kenwood TS-890, and if you dig around the menu's, there's a button that lights up on the right for "linear" control. In here, you can set a "delay". I turned "on" the (adjustable) default "15 ms" delay, and Wella! - the power meter problem is GONE GONE GONE !!

So it's some sort of a amp, or T/R relay "glitch" of something coming from the amp that puts the MFJ 998 into this mode (of intermittently locking out the meter function).

BTW, before I solved this above issue, I gave up, and called Gigaparts for a refund. The nice gal there explained that the process is NOT like HRO where you have 10-days to return it to HRO or a full refund. You have to CALL MFJ, request a RMA mailing label, SEND it to MFJ, and then you have to coordinate with MFJ, so that when MFJ gets it, they call Gigaparts telling them that they got it, and then Gigaparts will work the refund with you.

Hassle. That's when I decided to dig in. Glad I did - I think I might have single-handidly solved you guys's 'Power meter issue". If you amp has a "delay" setting for PTT vs. linear amp activation, then you NEED to put a wee bit of delay in there. I think I might make up a small device that you can put inline with the RCA connectors to do that for those of you that have amps w/o an adjustable PTT vs. Linear amp activation line feature. I'm good at designing, and building that kind of stuff.

In the mean time, just try to switch from SSB to CW *in flight* while transmitting (you need to have *some* power in SSB before hot-switching to CW).

Now the second issue, and my problem. (heavy DUTY troubleshooting).

When I tried to plug my AL-82 linear amp activation RCA jack to the 'linear amp out' jack on the MFJ 998 line the manual says to do, my amp instantly goes to TRANSMIT! That's not good! The linear amp control on the MFJ 998 is supposed to be PASS THRU! (The linear amp output jack is NOT interdependently controlled by the microprocessor). And I had NOTHING connected to the linear amp control INPUT jack. Strange.

Even with the MFJ powered OFF, plugging my amp control into the linear amp control OUT jack of the MFJ 998 would cause my AL-82 to go into transmit (w/ RED xmit LED).

Dove in deeply, and set up a small light bulb, power supply, meter, etc. to try to figure this out. I put a 12-volt light bulb in series with a 12-supply and connected it to the linear control OUTput RCA jack on the MFJ 998 to see if I can "visually" see if/when the 998 would release the output, and NOT key up the amp. Nada, - nothing I could do would drop this line.

However, somewhere along the line, some test clips got shorted out on my series light bulb on the linear amp control OUT jack, and SMOKE started to roll out of all of the air vent slots. Jesus-H ....

Opened it up, and geeze, - the two little wires going up to the two RCA jacks for linear amp control (IN *and* OUT), were melted beyond belief! Insulation completely gone, and the 2 little beads just dangling on the toasted copper of what was once two little wires going to the RCA jacks.

Perplexed.

Took a break, and replayed in all in my mind. Got to thinking, WAIT! WHY was the amp control *INPUT* wire burnt, - I don't connect *ANYTHING* to the amp control IN jack, - only the OUT.

Well, I actually DID find the schematic to this thing, and the linear amp control IN and OUT simply pass thru N.C. contacts on a little 5amp relay on the circuit board below the RCA jacks on the back panel.

Did a WHOLE bunch of good-ole fashion electronics troubleshooting and found the issue! There was a SOLDER BLOB on center terminal of the RCA jack for the linear amp control *INPUT* jack !

It was hard to see, as these RCA jacks aren't of the highest quality, and there space between the center post of the jack, and the threaded barrel around it is small. I even missed it after I fixed it once.

That explains WHY the one little wire going from the PCB to the INPUT jack from amp control was ALSO melted (when I had absolutely NOTHING connected to the INPUT jack) - the short was AT the actual connector, and fault path was: center post of the RCA jack for the amp control OUTPUT, down to the PCB, thru the relay, and up to the wire to the INPUT jack, except shorted to ground thru a solder blob.

Luck: had I NOT had my clip leads short out, and had I NOT used a 17-Amp power supply, and had those wires NOT melted, I would not have FOUND this issue.

(although I *DO* wonder why the short-circuit protection in the new 'TekPower" power supply didn't prevent the wire melting event in the MFJ 998).

So, after fixing that, and just moving the totally burnt wires with no insulation on them in such a way as to not short out (I'll replace them later), I was able to plus my amp control into the OUT jack of the 998, and it wasn't automatically keying up the amp.

BUT! - *more* hours go by, and MULTIPLE sizzle (arcing) sessions with my beloved AL-82, I found that the 998 wasn't actually controlling the amp.

Thinking (from years and years of electronics design and troubleshooting), that with the amount of current that went thru the wires to melt the insulation off like that, I'll bet I "welded" the contacts on that poor little relay.

Yup. I carefully shorted cap C165 (I think it was) to energize the relay to where I can hear a faint click, and it wasn't interrupting the path between the lineal amp control INPUT and OUTPUT jacks.

Great. No easy way to get that relay out - that's a main board RR task. Ouch!.

Soooooo....

I decided to just 'dummy in' another small relay into the circuit, and Scotch-tape the relay to the old relay. (I *own* the 998 now for sure, and there's no returning it to anyone now!).

Well-A - the 998 is NOW controlling the linear amp!

Rather nicely (and quickly) I might add.

If the SWR creeps up to past the trip point of a re-tune while at FULL legal limit, the little relay activated, interrupting the linear amp control, takes the AL-82 OUT of transmit mode, clacks away for a few seconds to get a new tune, then drops the relay contacts and puts the amp back in transmit more.

Marvelous ! I love watching that happen. Seems to work well, and makes me feel better about the whole thing.

On to the third issue.

The 'honking'. When you exceed 1,500 Watts thru the tuner (FWD+REV?), the display says: Opps, Over power !! and sends QRT in CW at you, and then BLAP, it goes to BYPASS mode (hotswitch while STILL at 1,500 Watts).

Ouch.

That CAN'T be good for those 2 length-wise bypass relays along the back edge of the PCB.

After ALL that work with the "amp cutout" on high SWR stuff I just went thru, I'm left scratching my head wondering WHY they would HOT SWITCH the bypass relays (when you have working computer logic/hardware to de-activate the amp).

Once you trip the "Opps!! - over power" mode, and a bypass is initiated, you can't just reduce drive a little bit on your radio, - the amp needs to go thru a WHOLE NEW RE-tune!! (it was *ALREADY* tuned before the over power event).

But what about my beloved $3.5K Ameritron AL-82 ???

My antenna (for background context) :
I have a wonderful Inverted-"L", with the vertical component about ~50 feet, and only about 8-9 feet or so on the horizontal. It naturally resonates on 3.900 at 1.09 : 1.

In the CW portion of 80, the SWR is 3.0+ on like 3.550 Mhz.

If you are careful, the MFJ 998 handles this nicely, and carefully tuning my beloved AL-82, all is well - pretty full transfer of power (just don't look at the SWR meter sitting between the MFJ 998 and the actual antenna !)


Here's the danger scenario:

In the above mode, IF you creep up on, and hit the afformentioned high power trip out (by increasing drive on your exciter), the 998 initiates a HOT SWITCH bypass mode, effectively taking the tuner OUT of the circuit.

This, in an INSTANT, presents the 3.0+ SWR to the liner which was running full power 1.5 KW into the load.
In the case of the Ameritron AL-82, this results in a VIOLENT ARCING situation, and you BETTER let off the PTT, and but QUICK.

I'm afraid to look in my amp to see the plates in the variable capacitors. I might cry. This amp isn't old, and I love it, and I totally cherish it.

So THAT'S the danger scenario that potential buyers need to consider.

PRO's:
- "it generally works as a tuner"
- meters (analog + digital) are "reasonably" accurate.
- The 'auto switching from low power scale to high power scale on the analog meter works well.
- Form-factor of the chassis is nice.

CONS:
- Quality of solder joints of PCB to "chassis components".
- Minor paint/scratch/cosmetic issue (expected with MFJ stuff)
- The HOT SWITCH "bypass" cutout logic on high power trip conditions is WRONG and DANGEROUS !

I'll be calling MFJ to discuss this, It seems a SUPER easy issue to fix: have the computer in the MFJ 998 simply signal an amp cutout to take the amp OFFLINE, wait 15-20 milliseconds, THEN flip the 2 bypass relays (hot-switching 100 Watts is not a big deal).

I hope I covered everything. Contact me with any comments/questioins.


WD9IQN Rating: 2020-09-24
Working good. Time Owned: 0 to 3 months.
So far the MFJ-998 has been working good. I use it with my Acom 700S. I have the interface cable between my Icom HF rig and the tuner. I also have a LDG 1000proII tuner with the M1000 meter. The reason I bought the 998 was because it had the ability to control the key line to my amplifier. When I change bands I just hit PTT. The MFJ inhibits the key line to my Acom and quickly tunes to the new band. Ready to go. Simple as can be. I have had decent luck with auto tuners. They are not perfect but I think a lot of people have problems from either poor quality coax and/or poor grounds. Depending on your setup a 1:1 balun may be in order where the coax enters your shack. Have fun and 73's !
K8DXX Rating: 2020-09-18
Disappointed! Time Owned: 0 to 3 months.
Just took delivery on the MFJ 998 legal limit auto-tuner. $599 from R&L. Initially, I was very impressed. Unlike any MFJ tuner I've seen before, the back and underside panel are painted black with high quality silk screening for labels, etc. My unit powered up right away and worked as expected. The analog cross needle meter is a lot larger and easier to read than I expected. The digital display (watt meter, SWR, operating parameters) are easy to read and understand. It performed the minor matching problems I gave it on 80 and 40 meters. I like the built in amp protection circuit that more or less takes the place of the buffer relay I used to protect my Flex 6600 (which will now go back into place). Took a quick look inside and construction looked great.

THEN... I tried using it on the low end of 20 to do minor matching on my Mosley Pro 67C3 (40-10 meter antenna that it DID match in the low end of 40) which is set up for phone. After tuning at 20 watts, running any more than 200 watts causes the digital display to display garbage. I bypassed the tuner to just use it as a watt meter. Same problem! Just for grins, I tried it on 17 and 15. Same thing! Once the display goes to garbage, the tuner is totally unresponsive and must be turned off to regain control.

I considered my commercial grade grounding system as a potential cause. I cold see one band but not everything above 40. If there was a grounding issue, I would have expected to see it in RFI to our surround sound audio system (got to be 300 feet of speaker wire acting like an antenna) , computer speakers, or my RF sensitive Flex 6600. Nothing.

Called MFJ and they suggested that I go inside the box and try shielding one chip or another. Which chip and how? Regretfully, I think I'll be sending it back.
W9BB Rating: 2020-06-14
Honestly a good tuner . Time Owned: 0 to 3 months.
I just purchased two tuners last week from HRO . The first was a Palstar HF-auto and the other mfj-998 auto-tune. I don't need to talk about the palstar. I take the the 998 out of the box hook it up and find out that the forward power meter does not work on ssb ,(under high power) So I call mfj and they know that the meter won't work on ssb ( they said that there processor can't handle the speed of ssb signal ) WHAT! why would you make forward power meter that won't work on ssb.( will work in cw ) . . Ok so I call HRO and they say you have 10 days to return the product , Go ahead and try it. Well I have been using the tuner now for 4 days and I'm not going to return it. In fact it tunes GREAT, Its fast and compared to my ldg 1000 pro 2 it's much quieter . It tunes 80 faster and easier than the palstar ( the palstar is great) but 2 and 1/2 times more money . So the mfj is a real good tuner ! It tunes great ! its fast ! And not that loud ! If they ever come up with a fix for the meter on ssb it would be a big winner !