MFJ 9410 TX issue w/ pic of possible problem.

[ZigZag747]

Just purchased a MFJ 9410 for a little portable DXing...Packed it up with the MFJ 971 tuner and MFJ 2210 hamstick dipole on a 16' extendable painters pole and headed to the ocean...10m was booming, Rx was amazing, pulling in signals from UK and S. America...Once I figured out the pile-up wasn't going to get any better before the band shut down I keyed up for a QSO...After several no responses I starting going through my portable set up and began some field T/S...I noticed that when I keyed up the the tuner showed I was sending out 10w forward with a SWR of 1.2 but my 9410's meter would not show any variation in my voice just stayed keyed around 7 each time. I called up on 2m to a fellow Ham and he dialed in on my freq and said I was breaking his squelch but no audio was coming through...I realized then that I was going to have to take this back to the shack to open up and look at the audio chain on the circuit board...I'm not 100% confident that I've found the problem so I'm going to post a pic of my board and schematic to see if someone else agrees...I believe that C119 is missing and possibly R54 right next to it...I've heard stories of MFJ's being a hit and miss, I'm guessing I missed on this one... Appreciate any comments...

Ok couldn't find a schematic online, pdf manual omits it for some reason...will keep searching, I don't have a scanner so I can't scan the one that's in my paper copy of the manual...Thanks.

73,
Neil

 

[MarkWestin]

Just because a component "appears" to be missing doesn't mean that it is really missing. I have seen many types of equipment that appear to have one or more components missing. It is possible that the same circuit board is used for more than one model or even type of equipment and that each model will have the components needed for that model. It is also possible that there was a change in design where for example a part was no longer available and the new suitable replacement part requires less or different supporting parts than the original design used. Your best bet is to contact the company and ask for a schematic diagram and also explain the problem that you are having. There could be a well known or easy fix.

Best of luck with your troubleshooting.

Mark

 

[ZigZag747]

Makes sense...I'm in contact with MFJ but they're just taking longer than I'd like to reply to my queries...Would like for them to just tell me yes that's missing a component and tell me what the value of that part is so that I can quick fix myself...Reason for me posting, I had hopes that someone out there who has this radio would open theirs up and tell me, yep it's missing and here is what it is...Thanks for your reply, I didn't think of the board being used for other band models and maybe not all spots were used...now I'm going to do my best to work my way back through the provided schematic and learn a little more about how these work on a component level...Which in the long run isn't that bad anyway...Always learning something...

 

[KD8TZC]

I kind of look at MFJ as the Harbor Freight of Amateur Radio. Cheap stuff that may not last forever, but you can always buy a new one or two or three at the cost of there stuff.

The one positive thing about MFJ is their "No matter what" guarantee.

 

[ZigZag747]

Problem solved

After sending the picture to MFJ they replied back stating that the carrier insert jumper was visibly attached and that it should have not come from the factory like this and to just remove the jumper and attach to one leg for storage...after removing the jumper I field tested the radio and found it to be 100% operational...was working well with the MFJ 2110 HF sticks as a horizontal dipole on a 16' telescopic painters pole...Had to adjust the V-Reg for 10.5Vdc cause I plan to only use this with batteries, but once I did a quick tune up of the antenna and I was on the air making contacts in South America, signal reports were 5 by 4 at best but reports of punchy audio that made me stand out in the piles...Ive learned a lot about this HF radio since purchasing it though it was not sent out ready to run it surely got my nose in the books learning more about what could be wrong with it...Even though I wasn't the one who figured out the issue...hihi 73 best of luck and thanks for the replys...de KK4FKS and I'm clear...

 

[gcgrotz]

I was gonna comment on the fact that your friend could hear a carrier that shouldn't be present on SSB. Glad you found the problem and fixed it. Nothing like sticking your nose into the equipment to get some OJT.

Now work some DX while you have a few sunspots left!