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Reviews Categories | Antenna Tuners | MFJ 934 Antenna Tuner/Artificial Ground Help


Reviews Summary for MFJ 934 Antenna Tuner/Artificial Ground
MFJ 934 Antenna Tuner/Artificial Ground Reviews: 7 Average rating: 4.3/5 MSRP: $179.95
Description: 1.8 - 30 MHz 300 watt artificial ground / antenna tuner
Product is in production.
More info: http://www.mfjenterprises.com/products.php?prodid=MFJ-934
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WB3D Rating: 5/5 Sep 28, 2014 08:34 Send this review to a friend
Tuner and Ground Matching Work  Time owned: 0 to 3 months
I live in a condo and use a 30' 22 Gage wire antenna deployed out the window into a palm tree with a variable length counterpoise in the shack. The 934 tunes 10-40 meters appropriately (as does the MFJ 971 and 901). I have had issues with RFI in the shack especially the computer. I do a lot of digital modes. The Ground Matching section of the 934 does a good job in eliminating the RFI. However, it was necessary to adjust a cover screw that was shorting out the Ground Matching inductor prior to getting the inductance working. This is a new unit right out of the box manufactured this year. Now works great! Wish I had gotten it sooner. The 5 is for performance.
 
TA3EP Rating: 5/5 Jan 24, 2013 12:49 Send this review to a friend
Great tuner  Time owned: 0 to 3 months
Great tuner. Artificial ground is really functionel. It tunes my FT 857D smoothly at full 100W. output. Antenna is a 30 ft. longwire outside the window and 30 ft. counterpoise on the carpet. Works great on all HF bands and even on 6 m. No bad surprises, no electrical arks or any other botherings. I would recommend it.
 
WB3FXW Rating: 4/5 Jan 15, 2012 10:57 Send this review to a friend
It works, now  Time owned: more than 12 months
I have owned the MFJ-934 unit for 18 months. When received it did not function properly. I took the top cover off and again tried the tuner. It worked. That was a major clue about what was wrong. The two inductors were not level. They should be evenly spaced between the case bottom and case top, A straightedge across the top, front to back, confirmed that the inductors would short out against the case. I carefully bent the brackets that held the inductors to the case bottom until 3/8" space was above and under both inductors. Now the MFJ-934 works flawlessly. Had I not had a DOA unit on arrival, the rating would be a 5.
Buzz, WB3FXW
 
K7GLE Rating: 3/5 Oct 10, 2007 14:15 Send this review to a friend
Functional but not great  Time owned: 6 to 12 months
I have owned this unit (which looks different from the illustration on this page) for about a year. New Technician + HF license, old TS-530 driving a 25’ single wire antenna against a relatively close-by cold water pipe ground.

Out of the box it tuned the antenna acceptably across the HF bands I was licensed for but the ‘artificial ground’ function behaved strangely…the ‘reflected power’ needle (on the cross-needle power/SWR meter) would simply freeze and the ‘power’ needle (which is supposed to register your ground tuning adjustments) would not register at all, regardless of adjustments.

I returned it to MFJ, who promised me quick turnaround because it was such a new order. Ha. I didn’t get it back for nearly a month, even after repeated telephonic assurances it was ‘shipping out today or tomorrow.’

The ground adjustment did function after repair. I never experienced any RF in the shack (that I recognized, anyway…new ham, remember, and I was only using CW, not brushing my lip against a mic). I have upgraded my license and am using *somewhat* improved antennas (a simple vertical pipe with 2 radials trimmed to 40M, and a 10M vertical dipole whose top el is about 25’) now. I have no trouble tuning up to 1.5:1 or better on any HF band with the 934 – at what cost in signal loss I can’t say.

I get no response at all anymore from the artificial ground adjustment…nothing. Could be my excellent antenna systems?

As mentioned by others, I have noted some hand capacitance, but it’s only troublesome on 10M, where the tuning is particularly ‘twitchy.’

Overall construction seems lightweight for a supposed 300W tuner. This last weekend I noticed some internal arcing for the first time at 100W on 40M but haven’t looked into it any further.

Glenn K7GLE
 
KE5AKG Rating: 5/5 Apr 4, 2004 17:28 Send this review to a friend
my favorite piece of gear  Time owned: 0 to 3 months
I bought this tuner after I could not tune my attic dipole on several bands with the autotuner built into my transceiver. It tunes the dipole well, but I had even better results with a 70 ft
random wire and several counterpoise wires running around the room and out of the window.
With this setup I was able to contact 12 DX countries on 3 continents within 2 days (there was a contest on) using only 100 watts. After this positive experience, I installed a 50 ft
random wire antenna on the top of my rv in a v-shape. It is attached to the ladder and roof rack with dog bone insulators and nylon rope,
and to a 15 in long PVC pipe standoff in front
With this setup I so far made contacts as far away as Maine and Aruba on 40m and 20m. I did not get the RV setup to tune on 10m, 12m or 160m, but I hardly ever use those bands anyway.
Overall this is an outstanding piece of equipment for wire antenna fans like me. It is a great value for the money. My only gripe (minor) is that it has "hand capacitance", meaning the SWR changes when I touch the tuning knob, which can make it a little tricky to tune on some bands. Also, I wished they would make a higher end version of it with higher power handling, so that I could use an amplifier for my base station.
 
N0EYE Rating: 4/5 Mar 20, 2003 12:21 Send this review to a friend
Peforms well  Time owned: 0 to 3 months
I bought this unit because my shack is on the 2nd floor of our house...too far away from earth ground. The tuner performs well. I am able to tune my 130' dipole on all bands, 10-160M at 100W with no arcing or other problems. I believe the shafts of the tuning capacitors need to be better isolated, as my touch will affect the SWR readings.

The "artificial ground" seems to be functional, as I have no RF problems in the shack.

As the previous review said, the documentation could be a little better. I find it a bit confusing in places, but I've seen worse manuals too.

I would recommend this unit.
 
KB4COM Rating: 4/5 Apr 5, 2002 09:04 Send this review to a friend
Nice Unit  Time owned: 0 to 3 months
I live in an apartment, on the second floor. Due to being a renter, I can not run a proper RF ground. This being the case, I had significant problems getting reasonable SWR's on my antennas (I am using mobile whip types, in a mag mount, on the balcony). The MFJ-934 has shown it self to be capable of reducing the SWR's, to a great extent. Unfortunately, there are other problems here, that I can not control (like aluminum siding).

I have been able to use the "artificial ground" feature, but I would like to see improvements in the manual, it is somewhat short, and the illustrations are a bit confusing. Overall, I like the unit and feel that my money was well spent
 


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