In our local ham radio club ( UBA-ARA ) – two of our club members had a Yaesu FT-897 who seemed deaf in certain modes. I took both transceivers home with me and took a closer look.
Upon opening the transceivers, I quickly saw what looked like water damage on the IF crystal filters:
You can see some white deposit on those filters. My guess is that after re-flow/wave soldering these boards, Yaesu probably washes these PCB’s. However, the plastic used in these filter either is brittle, porous, or the bottom isn’t hermetically sealed.
Removing these filters is a pain in the ass. And I’m not overreacting here. The ground plane in this PCB is quite good and you can really struggle to get the solder out. (lead-free as well!). Here’s the PCB with the filters removed:
Looking at the flux in other places on this board, I suppose this transceivers has had work done before…
I opened up one of these filters to get an idea of the damage done. A sharp blade does the trick:
You can clearly see the copper oxide. No wonder this thing was deaf!
Anyway, it’s worth opening up your transceiver if you have an FT-897 to check and see if there’s any of that white “powder” on those filters. Big red flag if you see it.
Here’s a picture with already one new filter in place. Make sure to put the right filter in the right place…