Yaesu FT-950 issue - Please help!

[Elf36]

I turned on my Yaesu FT-950 this morning and called out CQ a couple of times. A local called back to me and said he knew it was me, but my audio is not readable. I did a full factory reset and still have an issue. The radio also seems to have a dead key on SSB as if I'm using am or fm at times. I've let the coax hooked up for a few weeks now that there's no lightning. The radio is ground to a 10' ground rod outside of my radio room, about 8' away from the rig.

I did have a quick Qso with another station on 6 meters this morning and did not have any issues. Just tried the radio on 6M and it appears to have the same issue.

[Elf36]

Just called out to a local station on 10M. He came back said, great you got it working. Then after my next key up, he told me it's going back to gurgling. ??

Made another contact on 10M @ 17:50 and then the TX problem started again?

[ThaDood]

I had that about 20 years ago with my original version late 1980's RCI-2950 10M All-Mode rig. Few things that I was advised to do:    1. Replace that teeny-tiny gauge of power cord cable for a way heavier duty gauge cable.    2. Look for any low DC valued electrolytic CAP's, like lower than 16VDC, and swap them out for 25VDC, or higher.  3. Look for any loose / intermittent connectors between boards, screws that make contact from a board's GND to chassis GND, and bad solder joints, (Especially around the rig's finals and modulation areas.) When I did that to my RCI-2950, RF power went just over spec, and ops told me it sounded great and perky. May last another +30 years. Another place for info is what use to be a Yahoo Groups for that FT-950, probably a '.IO' Group now and see if anyone else has come across these problems. Good luck to ya!   

[Josh]

Hard to prescribe medicine over the phone but typical causes of undesired fming are poor psu regulation and flaky vco caps.

[Elf36]

Thanks, Dood. The rig seems to be behaving now, but I worry it will act up again. I hope it doesn't need to be repaired by a professional. I can check for cold solder joints and any other outstanding loose connections, but anything else would be out of my comfort zone.

[Elf36]

Thanks, Josh. I will double-check the power supply. It's a Samlex SEC-1235M. I also have a small Astron and a Tripp-Lite power supply I can test with. I'm hoping the 2 factory resets have set it straight. Now I gotta reprogram my CW and voice settings. Just worked a station in Brazil on 20M SSB. Fingers crossed!

[RobRich]

If it happens again, consider unplugging and replugging the various connectors inside the radio to clean the contacts. All it takes is a little oxidation and a few ohms of added resistance to cause issues, especially on modern rigs with various ICs, microcontrollers, etc.

[Elf36]

Thanks, Rob, so far so good after factory reset. I will definitely keep that in mind though if it happens again.

[ThaDood]

I forgot to ask, but what are you using for a power supply? To run my 100W rigs full-bore on SSB and AM TX, my bro-in-law's Astron RS-35A is perfect, with current to spare. I've tried using an RS-20M, but 20A peak wasn't enough on SSB and AM peaks. I feel that you comfortably need at least 25A on a 100W rig. FM is different, running Class C, and I can get away with 20A there on 10M FM. Just another passing thought that I can't believe that I didn't ask about earlier. BTW, can you run a lower current PS with a 100W rig? Well, yeah, but at much reduced power. A 15A PS, ya might get away with 50W. 10A??? I wouldn't go over 25W. It like drinking, know your limit, stay within it.