EBG
Sad picture, isn’t it? For those of you that know the Kenwood TS-440S well it is a familiar picture: VFO#5 covered in “Evil Brown Glue“, or EBG as it is mostly referred to. As I wrote in my last post, I counted my unfinished projects and fixing my TS-440S was highest on my list, so I took it apart yesterday. Mine is actually not covered in much EBG at all, but that is because I already removed a lot of the stuff some time ago. But now that the shroud is off you can clearly see that the EBG has crept under most components. No wonder the VFO was unstable or not working at all.
I prepared everything well, so the actual disassembly of the rig and the VFO was a piece of cake. I put some more photo’s on my website for you to enjoy. I already discovered that I don’t have one of the transistors which needs to be replaced. Will have to get them next weekend when we go up to Taipei. In the mean time I’ll keep myself busy with removing the components and cleaning the PCB, which is a little more work than I anticipated. I’ll keep you posted. 73 de Hans
P.S. lots of rain and wind the last couple of days, which we haven’t had for a while. Apparently it cleaned the power lines of dust and grime…..and the arcing. The bands are nice and clean again.
Fong: I also, have a TS444. How or what to you use to clean off the EBG?
73 Mike KG8MTG
Basically you de-solder all components and pry them loose. With tweezers you remove the larger chunks of EBG. I then used alcohol and a cotton swab to moisten the stuff that was stuck on the board and with smaller tweezers scraped it off. Take care not too scrape too hard because then you remove the print from the PCB. Then you clean the solder side of excess solder and resin and drill out the holes again with a 1 mm drill bit. I took me a couple of hours, but now it looks clean as a whistle. I’ll post a photo on my blog in the next couple of days, so check it out.
good day dear OM ,
i have question about my same problem : is it possible to remove the EBG only with Alcool 95° or Essence , without remove other parts ??? tnx in advance , 73 de 7X5TV (TAHA)
Hello Taha,
I tried it, but it is not sufficient, since there is EBG below the components causing short circuits. Only since I rebuild the VFO it has been working again. If you are careful you can clean the components once they are out and reuse them. I would put in new electrolytic caps no matter what. Hope this helps. –Hans