LNR Precision Mantiz FX-2 CW Transceiver Review.

Started by gil, November 26, 2012, 08:03:46 pm

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November 26, 2012, 08:03:46 pm Last Edit: November 26, 2012, 08:47:34 pm by gil
I just received a Mantiz FX-2 QRP transceiver from a fellow Ham. The radio is a 40/30m dual band CW only transceiver: http://www.lnrprecision.com/mantiz/
LNR Precision also makes the PAR end-fed antennas and they have a 40/30m model to use with the FX-2. I use their 40/20/10m model and it works very well.
For $185 (I paid $125 used), you get great features and full band coverage with a digital display. The FX-2 is made in China. Here is the amazing part:
QuoteThe FX-2 weighs only 10.225 ounces (290 grams) with dimensions of 4.5″ length x 2.375″ width x 1.5″ depth.

That is small, very small!

So, I was pretty excited when the Post Office truck showed up and there was a small package in my mailbox after it left. I didn't lose any time plugging it in. First impression: Let's get the manual. The menus are not especially intuitive but easy to learn. You will need the manual however in the beginning. The case is metal, and everything is clearly labeled. It is heavier than anticipated, which shows a high degree of integration. I won't go into the details of every function, you can download the manual from LNR's site. Everything worked but for the TUNE mode, which crashed the radio. I had to turn it off to reset it. Hopefully this will be fixed in a future firmware release. Mine could be the only one with this problem... I did write LNR about it and another issue (filters) and got a reply within a half-hour:
QuoteHi Gil if you can send back to Me I will update and check out issue, No cost Larry

How's that for service!

I wish the SWR indicator worked, but that is part of the TUNE function, darn.. Changing bands and tuning is easy once you learned how. The receiver seems sensitive enough. I heard many signals, though the band wasn't quite open. There seems to be a working AGC, though a bit slow.

Receive current draw is 0.09A, transmit current is 0.58A on 40m and 0.44A on 30m.

Testing the TX: Using a small battery (12.5V), the output power as measured with my QRP wattmeter was 3W on 40m and 1W on 30m. The radio did not like my switching power supply. You will need a linear power supply to use it in the shack. Power using 13.8V was 3.5W on 40m and 1.3W on 30m. Operation on 30m will thus suffer a good deal, be warned. Tonight I was barely heard on 40m (Thanks Ray!), though, again, the band wasn't quite open at the time. 800 miles isn't bad on 3W given the conditions. The sidetone isn't very clean, I can see strong harmonics on the waterfall when keying. My Rock-Mites have the same problem. I don't think it's QSK-able. The display frequency is exactly the transmit frequency. I was picked up by the reverse beacon network, and another indication that transmit works fine. I am sure the FX-2 will work quite well on 40m. I will post operating updates as they come.

Filters: That such a small radio has variable bandwidth filters at all is amazing. If only they were aligned properly! Four out of five are badly off-center. Here is what I found (bandwidth/center freq.):

  • 800/800

  • 900/750

  • 1100/700

  • 1100/700

  • 1300/600

Only filter #5 (widest) is centered on the 600Hz sidetone. The narrower filters will be a problem... I hope there is a procedure to fix this... The units are probably not individually aligned at the factory.

The Mantiz is a great concept and has a great form factor. It does suffer from quality control issues (mine does at least). Let's face it, it is a cheap radio made in China. Again, for the price, you get a lot. Keep in mind that the unit I received is used. I do not know if the issues I describe were present out of the factory, but it can't be very old, as the model was introduced this year. There is nothing in the manual about alignment. I plan on keeping the radio in my bug-out bag. It is certainly small enough. If LNR could align the rig better, maybe narrow the filters to 400Hz and allow listening outside the two bands, they would have a real winner. The TUNE mode failure must be a fluke. There is nothing of that size on the market with the same features, as far as I know.

I will play with it a bit more, then send it to LNR. I have heard about, and just experienced, their good customer service. If it comes back fixed, it will definitely be a keeper!

These are my first impressions of the Mantiz FX-2. I will soon post updates below as I undoubtedly will be using it quite a bit in the near future, and of course after sending it in for an alignment. So, check back often!



My update and copy of Eham review. My hat is off to LNR Precision. Just read...

QuoteI found a Mantiz FX-2 for sale on Eham. This product came out recently so it was a fairly new unit, with the latest firmware; $120 including shipping, can't be beat. I really like the form factor. It will fit, with wire antenna and small battery into a cargo pants pocket. It is heavy for it's size, suggesting a high degree of integration. The radio is built in China. For $185, you get a lot. My two favorite bands, built-in keyer, wattmeter (forward/reverse), digital display and variable bandwidth filters (more on that later). Power is about 3.5W which varies with supply voltage, antenna and frequency. I have seen it as low as 1.7W on 30m, though I was calling tonight on 10106 and saw 3.5W... Your mileage may vary. The case is metal, feels solid and has tabs in the back to tilt the unit for easier viewing.

My first impression was that the radio is very small. The display has a nice blue backlight. I heard CW as soon as I plugged it in. There was two issues with this unit that I noticed right away. First, the wattmeter did not work and crashed the unit when selected. The filters were all off-center. I could only use #4 and #5 (widest). A 750Hz sidetone would be necessary to use all filters, or moving the bandwidths 150Hz down. Now, that such a small transceiver has five filters, in itself is a small miracle. It also has RIT.

The menus are not intuitive. Fortunately there are few functions and the manual is clear. It doesn't take long to remember everything. Messages memory works great, though there is no auto-repeat.

I would have left it at that if it wasn't for the wattmeter issue. I really wanted that function to estimate SWR, and thus not have to carry another piece of equipment. So, I emailed Larry at LNR Precision. He replied within an hour, asking me to send it to him and that there would be no charge! How's that for customer service?

A week later I got a package from LNR. It wasn't my Mantiz... It was a brand new unit! Impressive... I plugged it in and tried the wattmeter; it works. Some filters however are still off-center. Not such a bit deal, because they are all usable on 40m. On 30m, I can use #4 (600Hz) & #5 (800Hz). The same filters are wider on 40m.

The sidetone is 600Hz. As far as I know, there is no way to change the frequency. Someone please correct me if I'm wrong. You can change the sidetone volume with a small screwdriver. The headphones volume is essentially on/off. You can't hear anything until you turn the knob about 80%, especially on 30m.

I would have given it a 5 if it wasn't for the filters misalignment. It's not too bad, but still an issue on 30m. LNR's customer service also contributed to my good rating.

I had an 800 miles QSO with 2W on 30m using a Buddistick, so the Mantiz works, no doubt. I am keeping it. Again, you get a lot for such a small package. If anything goes wrong, I know LNR will help me out, no questions asked. I like their end-fed dipoles and plan on getting the 30/40 model available to use with the Mantiz; great combination. The Budistick works fine on 30, but not so well on 40 with the standard coil and whip. The K1 is still my favorite, but you can't just throw it in your backpack like the Mantiz. Definitely a great radio for backpackers!