As I have already mentioned, during our first roving experience in the September 2009 VHF-UHF contest we found out that my FT-897D had gone deaf on 6 meters. Several guys could hear us clearly, but we could not hear them at all or only just barely. We made a few QSOs, but it was painful. Something was wrong.
I searched several FT-897 forums to see if anybody else had had the same problem, but came up empty. I tried one potential configuration setting solution, but that had no effect. So, I was bracing myself for having to send the rig in and face an expensive repair.
Just by chance, I visited again the blog of Rex Lester, G8UBJ, looking for his transverter interface design for his FT-897. And there on his blog was a posting on his own FT-897 going deaf on.....6 meters. Hey, maybe this was it!
I corresponded with Rex, he told me about what he had figured out had gone wrong, we identified the part, and I ordered some from Yaesu. The part is Q3034 (a 2SC5374) and it resides on the PA board, just below transformer T3006 which is itself just below that yellow relay you see in the picture. Happily, once you remove the cover over the PA board, it's pretty easy to get at.
These are tiny surface mount transistors, smaller than a grain of rice. The transistors were $0.55 apiece from Yaesu. I ordered 5 and they charged me over $10 for shipping (ahem.) Still, if this was really the problem then it would work out as a bargain.
I put the rig on the bench yesterday. Swapping the part took only about 15 minutes--a little hot air to get it off, then tack the new part down while working under the microscope. If you don't have the facilities to work on surface mount parts, please don't try this--you'll screw up your rig and it'll be expensive. You must have magnification, a fine-tipped soldering iron, and a steady hand. A hot air source to remove the part is certainly the preferred way, to avoid tearing pads/traces. But if you have the right tools and technique, go for it.
Last night I did an on-air test with Ralph, KC9LBO and all was back to normal! Thanks a bunch Rex and Ralph for your help on this one. So, 6 meters is back in play and ready for the June ARRL VHF-UHF contest which is coming up fast.
73 de W9HQ