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Reviews For: MFJ-998RT Remote Auto Tuner, 1.5 kW, 1.8-30 MHz

Category: Antenna Tuners/Matching Networks

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Review Summary For : MFJ-998RT Remote Auto Tuner, 1.5 kW, 1.8-30 MHz
Reviews: 50MSRP: 769.95
Description:
An MFJ HF tuner (160 M-10 M), capable of 1.5 kW of power SSB and CW. It is an external tuner and can be installed at the base of the antenna, which yields better results than with the tuner in the shack. It goes well with the Ameritron amps: ALS-1300, AL-80B, AL-82, AL-1200 and AL-1500 legal limit amplifiers. It weighs 9.5 lbs and has an ABS plastic cabinet and stainless steel metal chassis. It measures 13.75x6.75x17.5". Matches instantly impedances from 12-1600 ohms and includes 20,000 virtual antenna memories. Has one coaxial antenna and a binding post for end-fed long-wire antennas. Upgrade firmware via a serial port. Includes a one year warranty.
Product is in production
More Info: http://www.mfjenterprises.com/Product.php?productid=MFJ-998RT
# last 180 days Avg. Rating last 180 days Total reviews Avg. overall rating
24503.4
W1BG Rating: 2016-02-06
One-Year Follow-up Time Owned: 6 to 12 months.
Get this thing!! yes, I initially had some issues attributable to MFJ's typically atrocious QA, but the replacement has been truly flawless, attesting to MFJ's excellent design. For a high power 1.5KW remote auto-tuner I don't think you'll find anything better and certainly not for a better price. Mine sits out in the hot Texas sun, which was creating an internal case temperature approaching 173 degrees (f). By giving it 3 coats of gloss white Krylon paint the internal temperature dropped to 113 degrees in the peak afternoon sunlight, a whopping 60 degree improvement (and highly recommended field mod in the warmer climates).
K8JHR Rating: 2016-02-04
Excellent and reliable Time Owned: more than 12 months.
I put one of these MFJ remote tuners on my 43 foot monopole two years ago - hidden under a fake plastic rock I bought at the hardware store - and it works super. It tunes 80 to 10 meters and has been completely reliable and as steady "as a rock" - as steady as the rock it hides under! You can read about it in the March 2016 QST Magazine (Hints and Kinks Column).

It could not be simpler or easier to tune. You just remove power from the unit (it takes 12v power over the coax feed line by way of a bias-tee injector) and it tunes immediately when the power is restored, and you give it a blast of RF. That's it. It shuts off and the signal bypasses the tuner circuit if SWR exceeds 3.5 and power exceeds 75 watts. So, it could not be easier or quicker to remotely tune the big stick.

After two years, I am confident it works better, and has less line loss, than trying to tune the big stick with a 4:1 un-un and a big tuner in the shack.

Now this is just MY take... your mileage may vary... but I am pleased as can be. Consistent and reliable results for over two years.

Happy days and Good DX to ya. / K8JHR /
LB2TB Rating: 2016-01-31
Working nicely ! Time Owned: more than 12 months.
I am using one of the 2 tuners that LA5HE mentions in the post (nbr. 5 below this one). I bought it second hand when it came back from MFJ service.

Been using it for a long time with an Inv-L for 160M.

Current setup is at the base of an 18M Spiderbeam pole. Tunes nicely on 80-10 meters.

73's de Lars, LB2TB
K7NN Rating: 2015-12-15
Save your money Time Owned: 6 to 12 months.
Biggest piece of crap ever. Does not do anything it is supposed to do. Don't waste your money on this.
W9OWO Rating: 2014-11-11
14 months followup Time Owned: more than 12 months.
This tuner is still tops in my opinion. I'm considering another 998 for use in the shack. Tuning is fast and accurate and operation is reliable. I've had zero problems with it in 14 months.
LA5HE Rating: 2014-08-09
Unreliable Time Owned: more than 12 months.
I have 2 of these, in order to keep one on the air. Reliability is the key problem. I use them only on 80 +160 m, mostly CW, with my 26 m high vertical. There have ben flash-overs on 160 from the thin coax to a soldering point on the PCB when I am using full power. Some components seem to not be qualified for the power level, suggestion that a redesign is required.
Now both my units have been returned to the dealer.
NR9R Rating: 2014-05-20
Ignore reviews with "0 to 3 months" of ownership. Time Owned: more than 12 months.
The first unit arrived with several bolts holding the cover with the heads torqued off. After drilling them out and fixing this myself the unit worked satisfactorily paired with an ALS-600 500W amplifier for about 7 months, then stopped tuning. Upon inspection I found a severely burned circuit board. Since the tuner was still under warranty I sent it to MFJ and received a replacement.

The second replacement unit showed unstable behavior and required several on/off cycles to get it to tune initiate a tune. I immediately sent this one back and the MFJ service manager agreed to send me a new MFJ-998 non RT which I promptly sold.

The MFJ-998RT is a great concept but it simply is not a stable product. After purchasing MFJ products for 15 years and tolerating the out of the box DIY repairs they require, my tolerance has grown thin. I can't recommend anyone buy this product.
NY6C Rating: 2013-10-01
It works - I would definitely recommend Time Owned: 0 to 3 months.
This tuner works and it works well. Note that you should test this in the shack AND READ THE MANUAL CAREFULLY. This isn't really a 'plug and play' tuner. You can get the most benefit from the tuner by setting up the tune memory locations. Many times when tuning a new antenna the SWR will get close - but you can manually tweak the tuning a bit to get it even lower. Then save this setting in memory. Once you do this on all of the bands in question you can just leave it alone and it will do its thing. I would give this a '5' rating if there was a way to control some of the switches remotely. You need to configure things when you first get it by taking the cover off - not a big deal but remote control of those internal switches would be awesome.

I have this tuner at the feed point of a 32' vertical (using a 40' fiberglass spider beam pole). This works well on 40M and is also a 5/8 wave vertical on 17M - great for DX. Would I buy this tuner again? Yes.

-Greg NY6C
G3SZU Rating: 2013-09-15
Part 2 of my report from early 2012 Time Owned: more than 12 months.
I installed my *first* 998RT in early 2012 and in a previous review on this site, declared that the "jury was still out"...well, the jury's in and has delivered its verdict: Guilty! I recommend that you do NOT buy this tuner. Here's why:

I had two doublets that I fed to the 998RT with 400 watts via a 1:1 balun. The doublets were switched by an external relay box. Measurements with a VNA told me that on all frequencies from 80m thru 10m, impedances at the antenna socket were *well within* the MFJ spec for both antennas. Unfortunately, no-one told the 998RT and it decided to burn out a couple of relays and made a nice big hole in the circuit board and burnt out several tracks.

The UK supplier was going to repair it...I asked them not to - how can you repair a big hole in the circuit board satisfactorily? I asked them instead to provide me with a new replacement as it was still under guarantee, which they kindly did, albeit an early model. This new one lasted a few months before *three* relays fried. Fortunately, no circuit board tracks were destroyed....

It is costly to ring the US from the UK but I rang MFJ Customer Services in the US to tell them what had happened and seek advice. I made it clear that I wasn't after a refund. I simply asked them for the range of *complex* impedances it would tune....to cut a long story short, they wouldn't tell me and treated me like an idiot and a nuisance despite the fact that I'm a qualified engineer. Charming.

In spite of being stone-walled by MFJ, I ordered three new relays from a UK supplier and installed them in place of the fried ones. Upon inspection, the old relays had experienced tremendous heat on the springs and contacts, presumably due to excess current.

In the month before I had to return abroad (August), the unit performed reasonably alright, but I had difficulty getting it to retune when changing bands. I have yet to give it a thorough testing and won't be able to until November.

My configuration is: doublet fed into tuner via balun. Chassis is connected to a good earth. Fed back to TX with 50 ohm 213 coax. I am now using one doublet.

When I bought mine, the total cost including P&P was the equivalent 1200USD.

JF1QBV Rating: 2013-09-11
Works and Excellent ! Time Owned: 0 to 3 months.
The unit has been working flawlessly carrying up to 1500W PEP with various types
of aerials, including a random wire and a magnetic loop. The unit is well-built,
featuring a couple of types of input terminal: for a coaxial fed and for a single
wire and grounding, employing robust ABS and stainless steel coverage.
Another feature is a self-testing function built-in. I recommend this unit !
(Also, thanks to Diana - N5TWI for the excellent service !)