| TF3ARI |
Rating:      |
2013-04-22 | |
| GOOD |
Time Owned: 0 to 3 months. |
Hi
Got this tuner one week agou and He do all what manual explain he can do and more.
I have 43 Feet vertical from Ziro five + 4:1 UNUN
I hook the MFJ 998 with coax from UNUN to tuner, cable around 1 meter long and there it is 30 meter to VL 1000 1 kw Amplifier finaly to Flex 5000.
I get tune 1:1 down to 1.850 Mhz and yes he also tune 6 meter to 1:1 but manual say he stop at 30 Mhz, and I have test him on 80m, 60m, 40m,30m,20m,17m,15m,12,10 and 6.
I have kay in 1 kw CW carrier and no problem SWR stay down, tuning time is around 5 sec or less.
I did get problem in start, I left my Flex at 100W tune power and tuner was not happy to start tune on all band, I use now 30W as tune power and tuner start right away and works great, so he he 5 star unit for me.
only negative part is that tuner is not waterproof, well he is weather proof and you need to give him better box if you live in horizontal rain area+ salt. And like long travel as I am in ICeland I did check all connector and fasten all bolts before install him.
73
Ari |
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| K6CTA |
Rating:      |
2013-04-07 | |
| 1.5 Year Review |
Time Owned: more than 12 months. |
| After using the MFJ-998 for over 1 1/2 years, I can still say that I am very pleased. I have had zero issues with it, and have used it on 80-10 with up to 1.5kw for extended periods of time in all modes. I know that MFJ can be a controversial subject (and one that gave me pause before my initial order), but it has been a very cost effective addition to the station. I still stand by my comments in my initial review - " I’ve used the tuner on CW, SSB and RTTY at full power with no issues. There are a lot of features to the 998, but it is easy to use. The convenience of having an auto-tuner is a huge improvement in operating. I’ve had no difficulty in the tuner finding a match. I must say that I have been pleasantly surprised. You do need to understand its limitations, and how it works. It may not be the fanciest looking piece of equipment I own, but it certainly does its job, and so far, does it quite well." |
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| KL2D |
Rating:  |
2013-02-24 | |
| Tuner LCD was DOA |
Time Owned: 0 to 3 months. |
I know MFJ has a reputation for poor quality control, but I wanted an auto-tuner and this looked like a good option for the price. I read lots of reviews and finally convinced myself that their QC was improving so I went ahead and ordered one. I have Ameritron and Mirage amps and have been very happy with them, so I thought maybe the parent company would be ok.
When the tuner arrived I made al the connections according to the manual. Tuner powered up and appeared to function, but the LCD screen which is necessary to control the tuner was dead - all black squares (all pixels triggered). Fortunately I got it from R&L so sending it back was super easy. I admit that I was disappointed, I really wanted this tuner to work!
I was going to call MFJ and try to resolve what is probably a loose component on the display board, but instead just decided to spend the extra bucks and get the Palstar HF-Auto. I don't really want a piece of equipment that does not work reliably. I've been very happy with all of my other Palstar equipment, it is top-notch.
73s
Justin
KL2D |
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| N4JA |
Rating:   |
2013-01-06 | |
| Bad MFJ quality control. |
Time Owned: 0 to 3 months. |
| I'm waiting for a replacement for the one sitting on my desk. When this one came in day before yesterday, right out of the box the Forward power part of the cross needle wattmeter didn't work. I tried to tune my coax fed dipole on 3505kHz, which is resonant at 3800kHZ, and I could not get it to match. I have a 125 ft dipole fed with ladderline and a 4:1 balun and it will match that antenna on every 75-80M frequency. But going to 40 M on the same antenna, there is so much swr that the foldback on that band will not let the transceiver put out enough drive for the tuner to tune. Appearantly it takes some minimum drive into the tuner for it to activate. If your transciver folds back because of high swr, you may not get it to work. But all things being equal, I didn't expect this tuner to be as good as a manual tuner. It does what I need it to do in my situation. It lets me tune the whole 75-80M band so I can use my linear. I have a Hy-gain 402 Discoverer beam resonant in the phone portion of 40M and the tuner will let me operate on 7005 kHz with my linear, but using the ladderline fed antenna, it will not tune. |
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| N8PVW |
Rating:     |
2012-08-17 | |
| MFJ replaced mine. |
Time Owned: more than 12 months. |
| This is an update from my 2008 review. I had mine for two years and very happy. Suddenly it quit working. It had to sit on my desk for a while but I finally sent it in for repair. They kept it over four months. I got it back and immediately noticed severe cosmetic damage not there when I sent it in. Hooked it up. Still not working. Sent it back. Waited another three + months. Got it back. No additional charge but still not working. Contacted the head MFJ repair guy. He had UPS pick it up and ship it back. A week later MFJ sent me a brand new tuner. No additional charges. So I am happy. The unit was way out of warranty. They only had a duty to repair it per what they charged me. But they stood behind their product which was years out of warranty and made everything right. Considering the thing costs almost $700 new, I don't know many other firms that would have went that far to please the customer. i would give them a five if not for the damge done in their shop by their repair techs. But MFJ will keep my business. |
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| K3USC |
Rating:      |
2012-08-01 | |
| Both of mine work FB ! |
Time Owned: more than 12 months. |
Have 2 of the 998's (I have 2 QTH's). Both purchased used in the $400 range. Both work 100% with no issues. Have run Alpha 89, AL-1500 & 80B amps through them. Maybe I'm just lucky ?
Wishes-that I could get it to tune with 4 watts from my Elecraft KX-1 and that it had more than 2 antenna connections. I'd buy another if I needed one. |
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| G3RCE |
Rating:  |
2012-08-01 | |
| Don't waste your money |
Time Owned: 6 to 12 months. |
I agree with W4HLN
I had problems right from the start and should have returned it to the dealer.
I played with different settings, read the manual, asked questions etc.
Looked inside and the pcb looked well soldered etc.
I put it aside for several weeks and used my 'excellent' CG5000 without any problems.
Then tried the 998 again, initially tuning with 10 watts then running 400 watts into it, when suddenly it decided to retune and of course this did the damage and I had to return it for repair, fortunately still within the warranty period. I just think that generally MFJ stuff should be avoided because of very poor quality control. |
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| W4HLN |
Rating:  |
2012-06-10 | |
| CRAP! |
Time Owned: 6 to 12 months. |
Never again!
Save yourself time and $$$...Buy the PALSTAR TUNER!...It may cost 3 times more but well worth it!....Buy anything else but MFJ!
The MFJ never tune's right....sometimes not at all....does not handle Rated power.....Not even 300 watts CW without the smoke coming out!...Buying this tuner and expecting support is like adding to your junkbox...It just aint gonna happen! MFJ sucks!
W4HLN / Ernie |
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| NT4X |
Rating:     |
2012-06-10 | |
| Works well after being MFJ's QC |
Time Owned: 0 to 3 months. |
First of all let me say the 4 rating is for the tuner concept. After a couple of hours of QCing and cleanup, it has lived up to its claimed functionality (so far).
MFJ had nearly lost me as a customer forever after an antenna fiasco that lasted months and was never really resolved.
I needed a legal limit auto tuner and debated for a while about this one. I decided to get one used (hoping any issues were already resolved).
The original purchaser mentioned he mostly used it on 40 meters and had not run into any problems.
I noted the following before taking the cover off:
1. The SO-239 that is the tuner 'input' (goes to the xcvr or amp out) had a very tight center receptacle (for want of a better term). So tight that I could not get a PL-259 to go into it without sanding the center post coating down quite a bit.
2. Peak Hold did not seem to function. I didn't pay too much attention to this problem since I had other things to resolve first.
3. On 10 meters, I had a severe issue with RF getting into the tuner when the power got above about 300 watts. Display would get corrupted, or blank and do other odd things. Luckily the relays 'held', but there were odd messages and junk on the display; had to power-cycle to get it back to normal.
I decided to take the cover off and look around. The main board is decent quality, but in keeping with what I have come to expect from MFJ, the soldering and the cleanliness of the board was just plain bad.
Many balls of solder floating around the board. So many, in fact, that I was surprised it worked at all. Some of them were of sufficient size and in positions that screamed 'short'. There needs to be a compressed air station after the wave soldering station at MFJ (as well as an inspector with a microscope).
One area had a 'blob' about 1/4" in diameter and pretty thick, covering an SMD capacitor and resistor completely.
The source of the problem with the SO-239 was easy to understand after seeing the soldered connection. Seems whoever assembled this part of the tuner, decided a large, high wattage gun and 3 times the necessary amount of solder was required. There was a huge blob on the SO-239, and twice that much had dripped down onto the main board. Essentially this connection had been way overheated and the center receptacle distorted.
Using a head mounted magnifier, tape, de-soldering iron, temp controlled iron with a 1mm tip and a pointed probe I was finally able to clean this up.
There were also several SMD solder connections that were not well done (had a glazed appearance). I had to manually resolder them.
The SO-239 had to be replaced (to MFJ's credit however, they did send me one at no charge).
I also noted the same issue with the Antenna 2 SO-239. It will have to be replaced as well.
This corrected issues #1 and #2 above. #3 required a couple of additional parts.
I noted a snap on choke with several turns of the power lead helped the RFI issue a bit, but not enough. I decided to see if additional bypassing would take care of it. I added a .1uf 50v cap right after the long wire with a ferrite bead on it (choke), on the main board where the power lead comes into the unit. It's easy to find if you just look at the large electrolytic capacitor on the right side of the board (looking at it from the front), and trace backward, toward the coaxial power connector. Other side of this capacitor is grounded to a pad near by that is unused (verify that it is indeed grounded). So basically a .1uf capacitor is connected to the far side of this 'choke' (the side closest to the large electrolytic capacitor- tack soldered), and the other cap lead grounded.
RF also gets into the unit through the display. Another .1uf across the leads that supply power to the meter bulb completely eliminated RFI issues (they are marked 12V and GND I believe. This is on the display board).
Having read numerous posts about corrupted display issues and odd messages, I suspect adding these caps could solve problems with other units.
If you have a lot of RF, improving the station RF ground first would be the most prudent thing, but I still think this tuner needs better bypassing.
It's not like 2-.1uf caps would increase production costs by much.
With these corrective measures taken, the tuner works well. However I would plan on taking the cover off and doing the same things I did if you decide to purchase one. And I would do it BEFORE ever applying power to it.
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| G3RXQ |
Rating:      |
2012-05-18 | |
| A bit of a surprise ! |
Time Owned: 3 to 6 months. |
Searching the web for High Power Automatic Tuners I came across the MFJ-998.
Having seen the build quality of some of their products I was a little hesitant about the purchase. However, as I have a good relationship with my local dealer I figured that if it did not work I could get my money back.
The other deciding factor was that the majority of the unit was on a PCB that would have been made using Pick and Place and Flow Solder techniques, so that only left a small percentage that could be influenced by assemblers.
This turned out to be the case. The only problem so far was a flashing meter lamp. The supply wire to it had no solder at all. However, they had managed to splash solder over the nearby ribbon cable. I removed this.
The unit works very well with only the occasional failure to tune as experienced by others.
It also matches my shortish doublet on 160m, a feat which other ATU's I have cannot.
I would give it 4.5, however as it has been such a pleasant surprise it's a 5.
Stewart G3RXQ
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