MFJ-904H Tuner?

Hi all,

I did a bit of searching about this ‘small’ tuner that can also handle some power (more than the amazing ZM-2 QRP I have now).

I read mainly good thing and some odd ‘bad quality’/‘wrong readings’ reviews.
Any ideas form the more experienced here (than me… as Im uber newbie)?

(The balun and longwire feature is great for me, as the only thing that works at the moment for my QTH is a random wire + 9:1 balun on a fishingpole!)

73 and happy dxing in 2015!

One use,s the MFJ 949D for many a year now had no problems with it even out and about portable

Plus you can insert 12v supply to rear to make the signal meter light up



I’ve used one of these for over 400 HF activations now without problems, admittedly only at QRP levels and into balanced antennas and mainly on the LF bands (80m, 60m and 40m). I usually use a “standard” doublet made from computer ribbon cable (like the Norcal, but longer) that I set up as an inverted “V” on a 7m fishing pole and I’ve stuck a table of approximate settings for the various bands to the top of the ATU - makes setting up and band changing very quick. If it doesn’t tune at or very near the expected settings, it’s always been a problem other than the ATU itself!

Some people favour link dipoles and deride the use of an ATU due to potential losses, unreliability etc. but in practice it works fine and I’ll take the advantage of band changing without having to move from a sheltered position, snow hole etc. any day :slight_smile:

You occasionally see reviews taking a pop at the build quality of MFJ equipment, I can only speak as I find - I have given the MFJ-904H and an MFJ-259B Antenna Analyser hard use over a number of years without problems so no complaints from me. YMMV…

73 de Paul G4MD

I think the best description is it is “variable”, Paul. Aware of the reputation, I checked my 259B when it arrived and I can’t find fault with it. It’s been working for 10years without issue.

The other issue is optimistic power handling specs. MFJ are not alone here, a lot of 3kW ATUs only have that power rating when the antenna is better than 1:1.5 in the 1st place :smirk:

I was considering buying one before I decided to get a different model. According to various sources there is an occasional quality control problem, in the case of this model it appears that you get the occasional badly soldered joint on the range switch, and sometimes the grounding of the PC board via a couple of screws can be chancy. It is said to be easy to fix, you just have to re-melt the poor joints and work the screws a few times. On the other hand, this tuner isn’t sold as a kit! I would say that if you like it, get one, but be prepared for the possibility of doing a little work on it. Otherwise, I am with Karl, the MFJ-949 is a tremendous piece of kit with the virtue that it includes a dummy load. However, having said that, if you are using a random wire you might be better off with the MFJ-16010, which is also more portable - and cheaper!


The 904H I own is not “PB2T travel proof”. I remember having issues with the inductance knob.

73, Hans PB2T

I got some pointers towards MFJ-971 that they say is a ‘bit’ bigger and has the air inductor too. Thoughts?

I have had no problems with my MFJ 904 tuner. I placed on the back a Banana Plug Socket , I just drilled a small hole in chassis and secured it tightly that way I can use this same tuner with a end fed wire and a doublet fed with ribbon. I have used it many times over the last couple years on SOTA activations and made plenty of contacts locally and dx while activating. I set mine up with both end fed and doublet antennas then worked out the inductor and capacitor settings using the MFJ analyser and I made a note of these settings in the back of my SOTA log book . So when I go to say 7 MHz cw I read the settings from the book for what the EFRW 58 footer are for EG , Inductance C Transmitter cap 10 Antenna cap 5.
Or just peak the band noise that will get you close. Switch on the auto QRL in the rig and by the time the first cq has gone out you can tweek the SWR on the cross needle meter. The banana plugs on my antenna go in hot side of the SO 239, counter poise into the banana socket I put on and a short patch lead of coax to my rig, be it the kx3 HB1B or FT 857
it works with all 3 rigs no problems. I have not used it with coax fed antennas as a tuner because they are resonate link dipoles and like to have then not needing a tuner . That’s my experience with the Tuner you are asking about.
73 de Ian vk5cz …
ps its 5 am here and 26 degrees C we are in for a hot one today …