Ham Radio MFJ-259B Antenna Analyzer Repair

In building the ham radio 40/80 meter inverted v antenna I ran into a slight set back. My SWR readings were very high and I first thought my antenna or cable to be bad. Fearing the worst I found the problem. A short circuit in the SO-239 connector in my MFJ-259B Antenna Analyzer. This is how I repaired it.

Category:

Education

Tags:

• ham radio
• MFJ 259B
• MFJ259B
• amateur radio
• dipole antenna
• inverted v
• 40 meter
• antenna
• analyzer
• repair

[snuitje100]

Good informational video. I was less lucky with mine. Due to somebody not knowing how to work with such a device my Schottky diodes went to heaven. Lucky enough i was able to buy new HSMS2820BLKG diodes. Mind you, these are SMD types and are very small. One have to be carefull not to wreck the PC-board lines when de-soldering them. I used Chemwick litze and a 0.8mm tip on the soldering station to get them off. It resulted in a working device again. Be carefull with large signals! 73, Stan/PD0LUR

[MrHarveyluke]

I had to send my MFJ-259 back to Starkville a couple of years ago. It's about 10 years old. They charged me about $80. Be careful also that you don't let your batteries corrode in that thing. Your iron tip didn't look like it was shiny and tinned but it was in a shadow. Be sure it is clean and tinned for max heat transfer for a quick solder job. Also, try to test it before you assemble it all back put 74 screws back in the thing, so you don't have to take them all out again! 73, KM4JA

[ky5u]

Too long contact with soldering iron. Get the solder to flow and get on and off. It may not hurt a connector, but components down stream. Glad you were able to fix it.

[kb9gkc]

My Fan dipole covers 160/80/40 meters, the FT-1000MP swr meter says will read 1.2 and the Radiocraft 3000Pro will read 1.2 and the radio works fine (no power cutback) but the analyzer will read real high. Analyzer works fine on all other antennas like SteppIR and VHF UHF antennas. I think the MFJ 259B doesnt like Fan dipoles, anyone else experience this? Nice video by the way and thanks for the help. 73 Douglas

[userfixit]

Dave,

Another informative video; and should be helpful to many others. So many problems/solutions are mechanical in nature.

I have a 259B also and it is in use very often. A real time save save compared to checking with a rig and swr bridge. I also have the Dip Coils for it.

Of course, the 259 does much more than that... that is another subject.

Keep up the Great work since it is appreciated. Dust of that Guitar some time - I know you will tune it perfectly !!! LOL

-Bob KQ2Q

[elesjuan]

I ended up completely replacing the SO-239 in my MFJ-259B shortly after buying it. Started giving me erroneous readings on everything I attempted to measure so I took it apart to check the connection. Both ground and center pin looked like they made a good connection but I opted to replace anyway. Removing the circuit board from the case enough to get that SO-239 out was a treat, but an easy fix for my meter!

Nice video, btw!

[mrppassman]

A helpful, quality video. Clearly visual with good explanation. I hope I don't need to make this repair to my analyzer, but it's good to note what can go wrong and how to easily correct it.

73's,

Paul, WB0BBC