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Reviews For: MFJ-971

Category: Antenna Tuners/Matching Networks

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Review Summary For : MFJ-971
Reviews: 55MSRP: 99.95
Description:
1.8 - 30 MHz 200 watt portable antenna tuner
Product is in production
More Info: http://www.mfjenterprises.com/products.php?prodid=MFJ-971
# last 180 days Avg. Rating last 180 days Total reviews Avg. overall rating
00553.8
WA0DTH Rating: 2011-03-31
Factory TLC before ship needed Time Owned: more than 12 months.
I have been using this tuner in my car to fine tune the hamstick antenna. Then one day the transmitter tuning capacitor knob and shaft came loose and was causing the variable cap inside the cabinet was flopping around. Also I noticed on the inductance select shaft had a linkage where the set screw head was twisted off just leaving the threaded stub.
MFJ I like your products, but you need to inspect better and torque the hardware properly.
KJ6MEV Rating: 2011-03-11
re-review Time Owned: 0 to 3 months.
works just fine. i posted earlier and gave it a 3. now i find that the meter WAS working and my power supply wasn't. it tunes if the user does his-her part and takes the time to concentrate and make those needles go where they need to go. one can actually tune this thing very precisely.
KA4ZUC Rating: 2011-03-02
Tuner Quit Working Time Owned: 0 to 3 months.
After having my mfj 971 tuner for approx 6 weeks,it stopped working!! both needles,suddendly went to the middle of the scale and then dropped,never to arise again,upon contacting MFJ,they told me to check the two diodes on the circuit board for shorts,and if bad for "me" to replace them! so much for their "no matter what" warranty", no offer by them to even send the diodes to me!!! you bought it,its yours attitude!!! perspective buyers beware!! David Napier/ka4zuc
K9OPS Rating: 2011-01-06
Poor Time Owned: 3 to 6 months.
What can I add that wasn't expressed in earlier reviews. Just another disappointment, won't buy another item from MFJ without reading reviews first.
K1KUZ Rating: 2010-06-22
Nice Qrp tuner Time Owned: 3 to 6 months.
After reading all the bad reviews, I must addmit I was sceptical on buying one of these! But I did anyway. it arrived well packed and in good shape, and I immediatly open up the case to look for all the bad solder joints and bent capacitors, but didnt find any of that! maybe I was one of the lucky ones! I did notice, however, the crappy sheet metal work on the front panel! whats up with that? It looked like they just stamped it out and put it on the front of the rig! So I removed it and did a thurough filing and deburring job to take care of that. there were no other issues! It will tune any type of antenna, at QRP POWER LEVELS! and works great for me. You cant really expect a tuner like this to handle no 150- 200 watts, even though they say it will. But at Qrp power there is no problem. I would have gave it a 5 if it were'nt for the front panel. Just give it a good looking over before you use it.
KC0ZZH Rating: 2009-11-20
Junk for anything higher than QRP! Time Owned: 3 to 6 months.
I bought my 971 to replace an aging MFJ-941D. I wanted something to use here at the home QTH and out in the field.

I thought since the tuner it's self was small it would further enhance the portability of my new FT-857D. Unfortunately I never had the chance to take it out into the field before I started having problems with the tuner.

Right after putting it on the air into a resonant dipole I noticed from time to time it would arc on higher power. None of the tuners before ever did that and I could find nothing wrong with the feed-line/antenna system that would cause such issues. Opened up the unit to find that issue which some others on here found...bent plates. Spent quite a bit of time with the tuner and managed to get them straightened out. That solved the problems for a bit. About two weeks later it started arcing again and ended up burning through the inductance switch rendering the unit useless to me. I think MFJ's quality control needs to be improved and/or use better quality parts in the construction of their tuners.

I also don't like the fact that there is no coax bypass switch, although it's not a super big deal.

It did do an OK job at loading up on whatever I put it on, but once again I've had better results with other MFJ models.

In closing, I think this unit would be more than adequate for low power work but I can't give it good marks on higher power HF due to the failures that happened while I was operating.
KJ4NGS Rating: 2009-10-27
Open it up and inspect it first! Time Owned: 0 to 3 months.
I have a small corner of a desk for all my equipment, so I was attracted to this unit for its size, cost, and ability to handle my transmitter's output (200w PEP SSB).

But as I started working with it, my nose told me I was frying something inside ...

Opening it up revealed the following issues with my unit:

(1) The "Antenna" variable capacitor was misaligned, and so it was shorting out in most positions. Much time was spent re-aligning the blades.

(2) The knob on the "Inductor" rotary switch was not set properly, and so when I thought I had a mid-range inductance selected it really was basically shorting the TX to ground.

As a result of (2), it started to smoke the inductor switch as it was shorting out the transmitter. (The rotary switch is not designed to handle much power, I suspect!) The schematic is clear that the "A" position was a short (why do they even do that?), but the H position I thought I was using was a fair amount of inductance.

I clipped the real "A" connection internally (I never want to accidentally short TX to ground, thank you very much), and re-aligned the knob, and now things seem to be working OK.

I guess I didn't let ALL the smoke out of it yet! ;-)

So if you're lucky, you'll get a unit where both variable caps aren't shorted and the knob is set right and all will work well for you. If you're not lucky, and don't correct the problems in it first, you can fry the unit. I imagine this explains the disparate reviews I see here in eHam.
N3NXD Rating: 2009-10-02
Poor Quality Control Time Owned: more than 12 months.
Bought mine new April 2008. Used to tune up Icom 718 Transceiver. 100 watts.Noticed at times a fluttering of the cross match needles during TX. Finally It totally quit After warranty ran out, by 2 days.
Took case apart. Blown, cheapy made plastic band switch. Replaced with ceramic one from junk-box. Visual of inductor coil connections showed close coil winding to coil winding distance, and poor soldering. resoldered, and bent coils apart for more distance. Checked variable capacitor. Some plates barely brushing against rotor frame. Noticed charred material between some ( the fluttering needles) arcing. respaced plates. Took pipe cleaner and alcohol, removed considerable dust from between plates. Now works like a champ. No arcing.
OLLIEOXEN27 Rating: 2009-07-20
SWR roller coaster Time Owned: more than 12 months.
A lot of these 971s are made with pop rivets instead of tapping screws. Thus the SWR is unstable - all you basically have to do is bump or move the tuner and the SWR will show it. Another problem with MFJ tuners is faulty SO-239s whose center pins are improperly mounted in the casings. Buy at your own risk. Don't say no one ever warned you.
K5III Rating: 2008-09-27
Great little tuner Time Owned: more than 12 months.
I've owned my tuner for over 7 years now. I picked it up on eBay almost new in the box. I agree that MFJ has some challenges in the design on some things, however, this was one that was done right. It has performed flawlessly. The power reading is as accurate as you could get with a cross needle analog meter. If for some reason it is off slightly, it can be easily tweaked. It is light, easy to take with you, will tune a random wire with no problem. If you have problems using this tuner, then you would have problems with any manual tuner. It easy to use and great for QRP. I've used mine from 5 to 100w, and it worked every time. I am well please in the performance and price. The only negative is no bypass switch, but I haven't really missed it.