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Reviews Categories | Antenna Analyzers | MFJ-225 GRAPHICAL ANTENNA ANALYZER Help


Reviews Summary for MFJ-225 GRAPHICAL ANTENNA ANALYZER
MFJ-225 GRAPHICAL ANTENNA ANALYZER Reviews: 5 Average rating: 2.8/5 MSRP: $398.00
Description: Basic analyzer functions plus a host of advanced features like builtin LCD graphics, two-port VNA measurement, PC-Interface using IG-miniVNA freeware, and precise DDS frequency control.The MFJ-225 simultaneously compiles and displays all important parameters you need on a single screen, giving you a wider range of results at a glance.
Product is in production.
More info: http://www.mfjenterprises.com/Product.php?productid=MFJ-225
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WB0KZB Rating: 3/5 Apr 21, 2014 17:08 Send this review to a friend
Works, but...  Time owned: 0 to 3 months
I got the 225 shortly after the March 2014 QST review came out. From that review, I was not expecting professional grade instrument or deadly accuracy. All I want is something that will get me in the ballpark reliably. It works, I've used it to adjust all the antennas in the shack an in the truck. The reason it is a three is the switches bounce (pressing a button once may get 0-4 steps), the screen flickers, and it's just slow and awkward.

I can't speak to the calibration, but the QST article does mention how to calibrate it. The instructions that come with it are a little light as well, but who reads instructions anyway.

Bottom line: It works, but it's just not ready for Prime-Time. If you are used to professional equipment operation, get one of their other analyzers. If you want an affordable graphic analyzer, get this one and stand by to be a little frustrated with the operation.

It's worth what I paid for it and I'm keeping the one I have but I'll be looking for a better one in a few years when they work the bugs out.

73,
Jim
 
G3XOU Rating: 3/5 Dec 19, 2013 13:36 Send this review to a friend
Has a few issues  Time owned: 0 to 3 months
I purchased the MFJ-225 from a UK Ham Radio equipment supplier (Martin Lynch & Sons Ltd). On unpacking it I noticed that the rotary encoder knob had quite a bit of lateral movement.

The power ON/OFF push button and the power source selection push button are mounted to far back inside the unit. This results in them having a tendancy to stick in the down position against the front panel.

On taking the cover off to fit the batteries noticed that the thin grey coax from the DDS RF Source was touching the inner connection of the SO259 output socket.
Whilst this cable is insulated I found that its proximity to the centre pin affected the SWR reading on the higher frequencies by its capacitive shunt effect to ground.
This was easily fixed by moving the coax.

The lateral movement (wobble) of the rotatary encoder is due to the encoder not being secured to the side panel with a nut on its threaded bush. It is only secured by the soldered connections to the main PCB. As there is a gap between the encoder body and the side panel I fitted a 1/4" washer to take up the gap and secured the encoder to the side panel with a 1/4" thin nut. Having resolved these two issues I then decided to check its performance in more detail.

Whilst the MFJ-225 cannot be considered as a lab quality instrument I found that its performance in terms of SWR/Return Loss accuracy falls away rapidly after 130MHz which gave me concern. This is mainly due to the DDS RF output source rapidly reducing in level which limits the dynamic range of SWR/Return Loss measurement at the higher frequencies.

Here are the results:

MODE: ANT-G

BATTERY VOLTAGE: 4.77v

RF LEVEL MEASURING INSTRUMENT:
RACAL-DANA 9301A TRUE RMS RF MILLIVOLTMETER
USING ITS INTERNAL 50 OHM LOAD.

MANUFACTURES RF OUTPUT SPEC: -5dBm

FREQ O/P Level DISPLAYED
MHz dBm SWR
1 -3.2 1.10
2 -2.8 1.08
10 -2.5 1.07
20 -2.5 1.07
30 -2.8 1.07
40 -3.0 1.08
50 -3.0 1.08
60 -3.0 1.08
70 -3.0 1.11
80 -3.0 1.12
90 -3.2 1.15
100 -3.6 1.18
110 -3.8 1.19
120 -3.9 1.20
130 -4.1 1.20
140 -5.1 1.19
150 -6.5 1.19
160 -7.0 1.20
170 -15.2 1.39
171 -16.6 1.46
172 -18.0 1.56
173 -19.0 1.65
174 -20.3 1.76
175 -21.5 1.91
176 -22.8 2.13
177 -23.9 2.41
178 -25.0 2.72
179 -26.0 3.17
180 -27.4 3.66

At this point I wondered if I had a faulty MFJ-225 as I expected the RF output to be stable within +/- 1dB across its measuring range like the MFJ 259B which I also have. I contacted Martin Lynch & Sons Ltd who checked the three of the units they had in stock and confirmed my test results and reported their findings to MFJ.
However, it appears that this is how the all current production units will be until MFJ fix this issue.

Maybe MFJ will sort out this design defect in the "B" model together with the other mechanical issues mentioned above!

I also checked the frequency accuracy of the DDS RF source:

FREQUENCY ERROR AT 1MHz = +8Hz
FREQUENCY ERROR AT 90MHz = +632Hz
FREQUENCY ERROR AT 145MHz = +1.01KHz
FREQUENCY ERROR AT 180MHz = +1.3KHz

The link in the manual to the IG-miniVNA software no longer exists. I eventually found it at:

http://clbsite.free.fr/downloads/Ig_MiniVNA_v_2010.06.11.zip

In summary:
I like the MFJ-225 with its flexability to use as a stand alone VNA when working outside on antennas together with its ability to connect to the IG-miniVNA software but it needs a bit more work done on the product design before I could give it a higher rating.

Things that need fixing by MFJ:

1. Fix the Rotatary encoder to the side panel to stop the wobble!
2. Make sure that the DDS RF Source output coax is routed away from the SO259 socket.
3. Reposition the Power ON/OFF and Power Source selection buttons further out when they are in the "IN" position.
4. Redesign the DDS RF output levelling amplifer to make it as good as the MFJ-259B RF output level stability. (My MFJ-259B measures 8dBm flat +/-0.6dB across the frequency range).

 
KQ4KK Rating: 4/5 Dec 5, 2013 08:22 Send this review to a friend
Third one works  Time owned: 0 to 3 months
This Analyzer is the same as the AA-100 Analyzer by Gulf Stream Electronics. Tho, I think they are not selling direct, now that MFJ has them.
Saw the review on HAM Nation. Seems like a neat product. Back Ordered it. Down loaded the FREE FRENCH PC software...yea. FRENCH.

THIRD REVIEW>
Just got a brand new 3rd unit direct from MFJ. It powers off of USB fine. It charges and runs internal nMH (provide your own) fine. The SO-239 is solid and does not make the unit reboot if you touch it. Seems to works as advertised. Is it better than the 259 or 269? Not sure yet, it is different approach. Of course it does not go over 180mhz.

SECOND REVIEW>
Second one showed up from HRO in less than 5 days turnaround. Would not run on internal batteries, nor charge batteries. Ran fine on USB power. SO-239 worked fine. Powering it from USB power, it seemed to do everything it is advertised to do. Called MFJ, talked to Jimmy. He emailed a return label and said he was sending me one that worked. I UPSed the second dead one back to MFJ. Waiting for the 3rd one.


FIRST REVIEW>
The BROWN truck delivered my 225 today. Put batteries in it. Charged it. Turned it on. Screen came up, then the menu. Attached an antenna cable. As I attached it to the SO-239 the screen flashed back and forth from opening screen to menu, then faded dead. Turned it off, rechecked the batteries, looked for loose screws (it is a MFJ label), and shorts/opens on the SO-239 board. Could not find anything. Back to HRO. They are sending me a shipping label. Hope this story turns out for the better.
 
KQ4KK Rating: 2/5 Nov 26, 2013 15:57 Send this review to a friend
2nd ONE DOA  Time owned: 0 to 3 months
This Analyzer is the same as the AA-100 Analyzer by Gulf Stream Electronics. Tho, I think they are not selling direct, now that MFJ has them.
Saw the review on HAM Nation. Seems like a neat product. Back Ordered it. Down loaded the FREE FRENCH PC software...yea. FRENCH.

SECOND REVIEW>
Second one showed up from HRO in less than 5 days turnaround. Would not run on internal batteries, nor charge batteries. Ran fine on USB power. SO-239 worked fine. Powering it from USB power, it seemed to do everything it is advertised to do. Called MFJ, talked to Jimmy. He emailed a return label and said he was sending me one that worked. I UPSed the second dead one back to MFJ. Waiting for the 3rd one.


FIRST REVIEW>
The BROWN truck delivered my 225 today. Put batteries in it. Charged it. Turned it on. Screen came up, then the menu. Attached an antenna cable. As I attached it to the SO-239 the screen flashed back and forth from opening screen to menu, then faded dead. Turned it off, rechecked the batteries, looked for loose screws (it is a MFJ label), and shorts/opens on the SO-239 board. Could not find anything. Back to HRO. They are sending me a shipping label. Hope this story turns out for the better.
 
KQ4KK Rating: 2/5 Nov 18, 2013 13:04 Send this review to a friend
Broken as received  Time owned: 0 to 3 months
This Analyzer is the same as the AA-100 Analyzer by Gulf Stream Electronics. Tho, I think they are not selling direct, now that MFJ has them.
Saw the review on HAM Nation. Seems like a neat product. Back Ordered it. Down loaded the FREE FRENCH PC software...yea. FRENCH.

The BROWN truck delivered my 225 today. Put batteries in it. Charged it. Turned it on. Screen came up, then the menu. Attached an antenna cable. As I attached it to the SO-239 the screen flashed back and forth from opening screen to menu, then faded dead. Turned it off, rechecked the batteries, looked for loose screws (it is a MFJ label), and shorts/opens on the SO-239 board. Could not find anything. Back to HRO. They are sending me a shipping label. Hope this story turns out for the better.
 


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