View Full Version : MFJ-259B "SWR" Analyzer
w8cbc
06-17-2006, 08:34 PM
I just picked one up at a hamfest.
It measures impedance and figures out the resistive and reactive components. In the box you have a digital LCD display and a pair of analogue meters (one for SWR referenced to 50 ohms, the other for impedance).
It has a rather touchy knob-tuned VFO that operates in six ranges from 1.8-170 MC nominal (actually extends a little beyond those edges).
Tuning up with the thing is a snap. The meters get you close, then you can fine-tune with the information on the LCD. It puts out milliwatts so there's no need to QRM.
The contraption includes functions to measure inductance, capacity, line loss, frequency of an external source, phase angle of complex impedance, line length, more. It runs on 10 AA cells and has a trickle charger if you get rechargeables (I did).
I've been all over my antenna system with it, confirming some things I suspected and working out what to do about them.
This is one gadget I'm glad I got! I've had it maybe four hours and already it's my favourite bit of test gear.
KG6YTZ
06-18-2006, 06:57 AM
Yep... #Wish I could afford one of those goodies m'self. #I have a couple of friends who have them, so I've fiddled with 'em a bit, and...
Quote[/b] ]It has a rather touchy knob-tuned VFO...you ain't kidding about that. http://www.qrz.com/iB_html/non-cgi/emoticons/smile.gif That's probably the only complaint I have about those analyzers.
The Autek's are even touchier to tuune. BTW, milliwatt's isn't zero QRM; I was heard ten miles away while tuning a mobile antenna. Maybe I'll try QRP with it. 2.5 mW isn't too little to make contacts!
Cortland
KA5S
w8cbc
06-19-2006, 06:14 PM
Cool!
Maybe I'll add a key port to mine. http://www.qrz.com/iB_html/non-cgi/emoticons/smile.gif
Quote[/b] (kd8bsr @ June 19 2006,14:14)]Maybe I'll add a key port to mine.
You can run FSK just by touching the output. F1, anyone?
Cortland
KA5S
I bought mine at the Orlando Hamcation a three years ago and found that it was uncalibrated! It was new in the box and MFJ would only send me the instructions to calibrate it myself. I was miffed!
N3ATS
08-15-2006, 11:22 PM
A word of caution.
If you're using this thing, say, to look at your repeater antenna at the club building, make SURE no one transmits on any radio putting out any decent amount of power within a hundred feet of it.
I was checking an antenna, a nearby transmitter came on the air. Gone. Popped. Kaput.
w8cbc
08-16-2006, 12:06 AM
The instructions are quite specific about that sort of thing. But thanks for the reminder.
I found that it gave rather silly readings for my mobile whip at a transmitter site with one active class-A FMBC station about 800 ft. off the ground (the site is the backup for three class-Bs and another class-A). The field at 800 ft. wasn't enough to pop the thing, but it is rather sensitive.
N3ATS
08-16-2006, 01:58 AM
The instructions tell you to short the coax to prevent a static discharge from blowing it out.
I couldn't find anything about using near other transmitters. I probably (no, I did) miss that part. http://www.qrz.com/iB_html/non-cgi/emoticons/biggrin.gif
I now afix an attenuator to the thing before connecting ANYTHING.
w8cbc
08-16-2006, 03:59 PM
Specific was probably the wrong word. http://www.qrz.com/iB_html/non-cgi/emoticons/smile.gif
They made it clear to me though that the beast is not tolerant of RF on the analyser input and can easily fry.
M3GID
09-24-2006, 03:24 AM
I have a 259B - My friend "gave" it to me cos he kinda fried it, he now has the 269 which covers a greater freq range. Mine still works on resonance and a few other features just fine, but it is very sensitive to the touch when under test, I found it best to place it ona non metallic surface and to touch only the bakelite tuning dial.....if you don't believe me, tune yours whilst touching any metal part and then when tuned, remove your hand and see the difference! Other than that, it is indeed a very smart piece of kit (for an MFJ - "made from junk")
73 de Geoff
N7RJD
09-24-2006, 09:40 PM
I have the 269 and can tell you with a Hustler 6BTV and no tilt over, having to pull the bulk of the antenna down multiple times per band this thing is a lifesaver. If I had to run up and downstairs to key the radio and take a reading each time I would have called it close enough well before I had it where I wanted it.
The freq counter can be fun to play with too. Seems to be fairly accurate with a 2m duck snapped on.
The internal tuning does take some playing patience but all in all I have been happy with the tuner. I have mine in the MFJ case so not much problem with touching the metal housing. I also have the dip coils for it but have not had a chance to play with them and figure out if they are worth anything or not.
kb3eia
11-07-2006, 12:31 AM
The 259 and it's big brother are simply great when the cost is taken into account. Mine has allowed me to fine tune my antennas well beyond the point where I would have said "good enough".
They are sensitive however. Mine got fried once - not sure exactly how - but some others were playing with it. Perhaps someone was using it as a field strength meter??;)
I sent it back to MFJ, as it was still under warranty, and in a couple weeks it was back and good as new. Every Ham should have one of these. Especially since your friends will want to borrow it! http://www.qrz.com/iB_html/non-cgi/emoticons/biggrin.gif