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Reviews For: MFJ-993

Category: Antenna Tuners/Matching Networks

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Review Summary For : MFJ-993
Reviews: 123MSRP: 259.95
Description:
MFJs exclusive IntelliTuner™, Adaptive Search™ and InstantRecall™ algorithms give you ultra fast automatic tuning with over 2000 non-volatile revolving memories. You get a highly efficient L-network, wide 6-1600 ohm matching at full 300 Watts SSB/150 Watts CW, 1.8-30 MHz coverage, Cross-Needle and digital meters, aural SWR meter, backlit LCD display, remote control port, radio interface, heavy-duty 16 amp/1000 volt relays and more.

It learns while you're having fun
As you’re ragchewing, contesting or DXing, your MFJ-993 is learning! When you transmit, the MFJ-993 automatically tunes for minimum SWR and remembers your frequency and tuner settings. The next time you operate on that frequency and antenna, these tuner settings are instantly restored and you’re ready to operate in milliseconds!

Each of two antennas can learn and remember over a thousand frequencies and tuner settings. They are safely stored in non- volatile revolving memory.

Highly Intelligent ultra fast tuning
MFJs InstantRecall™ first checks its memory to see if you have operated this frequency before. If so, tuning is instantaneous and you re ready to operate. If not, MFJ's IntelliTuner™ algorithm - - based on MFJ's famous SWR Analyzer technology - - kicks in. It measures the complex impedance of your antenna. Next, it calculates the components it needs and instantly snaps them in. Then, it fine tunes to minimize SWR -- you’re ready to operate. It’s all done in a fraction of a second.

When the impedance is within its measurement range, the MFJ-993 is the fastest automatic antenna tuner in the world.

If it can’t accurately determine impedance, MFJ’s AdaptiveSearch™ algorithm goes into action. Frequency is measured and relevant components values are determined. Only those values are searched for ultra-fast tuning.

For even faster searches, you can set the target SWR to 2 (settable 1.0-2.0). You can manually tune when you can’t transmit (for listening out of ham bands).

Cross Needle and Digital SWR/Watt Meters
Lighted Cross-Needle and digital meters lets you accurately read SWR, forward and reflected power at a glance. An aural SWR meter lets you hear the tuned SWR when you can’t see or read the meters. Turn on a highly visible, instant response SWR LCD bargraph when you need it.

Backlit LCD Display
An easy-to-read backlit LCD displays SWR, forward/reflected power, frequency, antenna 1/2, L/C tuner values, on/off indicators and other information.

Remote Control Port
Plug in the MFJ-990RC remote control and put your tuner at your antenna or elsewhere and control it remotely. The MFJ-993 supports radio tuner interfaces such as the ICOM 706 series. Interface cables are available.

The MFJ-993 is a compact 10Wx2¾ Hx9D inches. Use 12 –15 VDC/1 amp or 110 VAC with MFJ-1316.

Tune any Antenna
You can tune any antenna — dipoles, verticals, beams, phased arrays, inverted vees, quads, random wires, mobile antennas, compact limited space antennas – practically any antenna. A 4:1 true current balun lets you tune any balanced antenna - - horizontal loops, vertical loops, multi-band doublets, quads, folded dipoles, Zepps.


Product is in production
More Info: http://
# last 180 days Avg. Rating last 180 days Total reviews Avg. overall rating
001234.4
KF6IIU Rating: 2022-06-01
OK, some problems...... Time Owned: more than 12 months.
This is a review of the "B" model.

A nice little tuner on a compact box. Altogether, it works OK, perhaps not as well as more expensive models that can handle more power or wider mismatch.

A couple of minus though: After a few years the front panel switches got flaky, even though they all pass self test. The tune button works fitfully, and sometime puts the unit in SETUP mode instead of tuning. The C-Up button continuously adds capacitance, but the C-Down and L buttons don't. The C and L buttons randomly switch the display mode too. This seems like a software bug.

The case construction is a big problem with this and other MFJ devices as well. They use self tapping sheet metal screws, which inevitably shed little pieces of metal when they are removed and reinserted. Be careful!

So you get what you pay for, and on the whole this device has really made operation easier, on the bands it can tune into a 140 foot ladder line fed dipole: everything except 160, the low part of 80, and 15 and 17. It does tune quickly and accurately, and is particularly handy for field day type operations since it can be powered from the radio.
W2GSH Rating: 2021-05-24
Works as expected Time Owned: 0 to 3 months.
I have an Icom 7300 and ordered the tuner with the expectation that I could tune more bands with my dipole antennas. The tuner did open up many bands that I did not have a specific antenna for.

There was a problem with the MFJ-5124i cable that I ordered. The day it arrived the tuner button on the radio did not control the tuner and I had to go to RTTY and key the mic to get it to tune. Eventually, I did a continuity check on the pins and found that pin 1 had no connection to the 3.5mm jack. I removed the pin at the radio connector and flowed some solder and then the radio controlled the tuner. If you have a problem, check your cable.

The tuner itself is a real pleasure to use so far.
W5PZT Rating: 2021-05-22
Switch problem Time Owned: 3 to 6 months.
I purchased one recently despite having read several reviews that mention the power switch frequently fails. I got a copy of the schematic and quickly spotted a problem. There is a 2200 uF cap on the main 12V line coming into the unit. Many people have this continuously connected to a source of 12 Volts. When you push the power switch that 2200 uF cap is connected through the switch and diode D34 to a 220 uF capacitor on the input of the 5 Volt regulator for the computer logic. I lifted D34 and soldered a 1/10 Ohm resistor in series and measured the voltage drop across the resistor. It was briefly (15us) 4 Volts just as the switch was pushed in. Ohms law says briefly 40 Amps of current went through that switch. I doubt the switch is designed for much more than 1 Amp which is the rated power supply. That kind of current - especially if the switch contacts bounce at all will gradually pit the contacts and cause failure.

For a solution, I lifted the diode, paralleled two 12 Ohm resistors and soldered the combination in series with the diode. This limits the peak current to about 2 Amps. It leaves plenty of margin to supply current to the 5 Volt regulator. Nothing will adversely affect the MFJ-993B as long as you have the skill to lift the diode from the PCB and solder in the resistors.

A reason some may have had no problem with the switch is that some transceiver cable sets provide the power to the tuner. If you use the transceiver power switch to turn on the tuner, then if anything your transceiver power switch will see a more modest surge not the MFJ switch.

My experience otherwise has been good except that sometimes when I tune at 10 Watts I'll get an SWR of 1.0 and then when I raise the power to 100 Watts the SWR will read higher - 2.0 to 1.

****
After close to 2 yr. ownership the changing SWR at different power levels was a persistent annoyance. I put the tuner in bypass mode and fed a dummy load through the tuner. The signal goes through the current transformer for power measurement. I hypothesized that diodes may be mismatched or something broken in either the forward or reflected direction.

I measured the voltage at the forward test point at different power levels and plotted a curve that was exactly what I would expect from a diode detector. I then reversed the coaxes so the transmitter was feeding the antenna connector and the input connector fed the dummy load. The tuner was still in bypass mode. Now I similarly plotted the voltage on the reflected test point at different power levels. The forward and reflected curves matched perfectly. There is no problem with the SWR bridge.

I also plotted the forward power reading and with the cables reversed the reflected power readings on the meters. The forward reading was almost the same as the reflected reading below 5 watts and above 5 watts the reflected reading (reversed cables) was much less than the forward reading. I verified the forward and reflected test points are directly connected to the microprocessor. This suggests that whatever calibration is being done in the microprocessor code is responsible for the significant difference. It seems like a call to MFJ is in order.

I also noticed the toroid L2 has two of it's three turns overlapping each other. I suspect they should be spaced apart for best insulation. The unit seems to tune my 240' OCF dipole rather well on all bands as long as I tune it at a higher power level of 30 to 40 watts. I would still rate it good.
N4UE Rating: 2019-07-01
Initial report - excellent Time Owned: 0 to 3 months.
Hi. Been a ham for over 1/2 a century. I mostly use resonant antennas, but I LOVE to experiment with Fan Dipoles, Long Wires, etc.
I have used an older MFJ-945E at my one person, Field Day operation for a few years. Using a 40-10 OCF dipole up at 'the farm', it was easy to make a chart using my Comet 500MARKll. However, I found I was spending more time retuning when switching bands, than actually operating.
Enter the LDG IT-100. This works seamless with my 706g.

In the home shack, I used an ancient MFJ-949C. Again, I made charts to get on a band/frequency.
Having been spoiled by an automatic external tuner, I started looking for a modern replacement.
Enter the 993B. Although I bought the matching Icom cable, I'm using the tuner with my TS-890 as well. I'm just letting the 993B tune when I send it RF.
Works amazing. I have had a LOT of MFJ products in my ham career and the ONLY issue I ever had was the cap plates on the 945E touched once and a while. It was caused by an assembly error. Trying to 'stretch' a wire. ha ha
I guess I'm just a luck buyer.

BTW, the 993B Manual is EXCELLENT.

ron
N4UE
K9IUQ Rating: 2018-10-24
MFJ does Good Time Owned: more than 12 months.
I have owned this MFJ-993B tuner for 12 years. It has been on many different rigs. It has been on MANY different antennas. It has been in my main QTH, my travel trailer and our WI summer cabin. Many of the antennas used were marginal and non optimum.

Not to worry as the MFJ 993B tunes everything I threw at it without any complaints.After 12 years the tuner looks a little ragged and beatup, but it just keeps working. Never a problem.

This is the FIRST MFJ product I have been entirely satisfied with. This tuner obsoletes ALL low power manual tuners and beats LDG auto tuners. GOOD JOB MFJ!

Stan K9IUQ
KC2YRJ Rating: 2017-08-09
Often, but not always, great! Time Owned: more than 12 months.
The 993B tuner works beautifully, most of the time. It matches my dipoles perfectly and very quickly once I use a frequency on which I've already operated. When operating on a new frequency, it takes only 2 - 5 seconds at most with a difficult load. The display and metering options are very useful. However- after about 2 years of modest use the power switch became inoperative (you've read about this in numerous reviews). I sent the unit into MFJ and had the unit back in a few weeks. The repair charges to replace the power switch came to just under $75, including return shipping. OK, this can happen; but after another year, the switch failed again and the thought of going through this every year is discouraging. I intend to simply lock the switch in the "on" position and just connect the A/C adapter plug to the tuner when on the air. You would think that after seeing this same complaint in several reviews that MFJ would use a better quality switch and having chosen not to do so sends a message to us that they really don't care all that much about their reputation. It's truly a shame because absent this malfunction, the tuner does an outstanding job.
KC9OMS Rating: 2017-02-19
Very good atu Time Owned: more than 12 months.
I have this tuner connected to my ICOM IC-7100 and the radio controls the unit totally. I just push the tuner button and the unit does its thing. I have an Alpha Delta DX-EE in a very tight setting and the SWR is challenging. The tuner matches the antenna to the IC-7100 with the SWR low if not 1:1. I have made many contacts with this tuner over the three years that I have had it. I never touch the controls. It just sets under the radio doing its thing as advertised. Great job MFJ!
N5LB Rating: 2016-12-19
N5LB Time Owned: more than 12 months.
UPDATED from prior post. I moved the tuner from one side of the op desk to the other and then it stopped tuning, anything. When appling 10W on any band the frequency readout was 0.000, the SWR F and R identical and showing very high. Not antenna related, tried various including DL. Looking at the schematic, T1 the RF sampling transformer seemed to be the only common component. One of the solder joints was "gray", looked cold. I reheated from the top of the boards and viola, all is good.

That said, much is made of MFJ QA and I think this is one of those cases manifested several years after manufacture. I did drop a note to MFJ support prior to resoldering and they responded very quickly with reasonable things to try, though not the one I found.

The tuner has been and is now very good, fast and tunes most anything I have. That said, MFJ QA....arrrggghhhh...

These seem like plated through holes and probably wave soldered. It's not as if someone on the assy line did a poor job and I don't know how you find this sort of issue before it goes out the door except maybe with visual inspection, always a great idea, or a shake table, not such a good idea unless you have mil spec products.
KD9ANE Rating: 2016-03-12
Doesn't Last!!! Time Owned: 6 to 12 months.
This tuner work just fine for about 8 months.... then it would tune up 3 different frequencies and then stop auto tuning..... then after the first power up it would tune only one frequency and then you'd have to push and hold the tune button for 2 seconds to get it to tune.... I've ran all the diagnostics, resets and then contacted MFJ with 0 results.... MFJ doesn't seem to care about product support.... What a shame...... I was warned by the older member in my ham club that you get what you pay for.... In the future, I'll only invest in the best products.....
W3WMU Rating: 2015-11-13
I BOUGHT A 2ND UNIT Time Owned: more than 12 months.
What can I say. I was very pleased with the first MFJ-993 unit that I bought a 2nd unit to replace my LDG 200 pro. Same money as the LDG unit but this unit does it quicker and more accurately. The LDG unit handles 6 meter but I am never on 6 meter much. I like that the 993 has a built in meter and LCD display.