12-14-2016, 12:13 AM
Well, now that I have some vacation time to burn, I have returned to my Philco 90 Lowboy. I think I have all the caps & resistors I need for the job, so I started on the power supply first. There have been numerous repairs made to this over the years. Every Bakelite block has been replaced with a wax/paper cap. The blocks are still there and it appears that the insides have been removed or cut out of circuit. They must have gotten awfully hot because most of them are just dripping with wax/tar. A real mess.
I decided to try something; and pulled the first block (across the power cord), removed it from the chassis completely, removed the paper caps tacked onto the terminals, and cleaned the terminals. Scraped out the remaining wax/tar with a screw driver. It was still a mess, all covered with wax/tar. I dropped it into the ultrasonic cleaner with hot water and a good "slug" of Simple Green. Turned on the heat and ran it thru 2 cycles of the cleaner. Pulled it out and it was almost like new. I completed the cleaning of the terminals with the soldering iron, which brought out a little more wax/tar around the rivets. So I dropped it back into the cleaner and ran it thru another 8 min. cycle. This time it came out absolutely clean.
The tone control was next to go into the cleaner, after removing the potted caps. Again, it came out clean, looking like new and ready for rebuilding. I don't know if anyone else has tried this, but it sure worked for me.
I have re stuffed many of the Bakelite blocks, but this radio is the worst I have ever seen. I have not had the need to clean them up before. Just cut the leads, apply a little heat and pop out the old potted cap. Easy! But this does pretty good. Looks much better.
I decided to try something; and pulled the first block (across the power cord), removed it from the chassis completely, removed the paper caps tacked onto the terminals, and cleaned the terminals. Scraped out the remaining wax/tar with a screw driver. It was still a mess, all covered with wax/tar. I dropped it into the ultrasonic cleaner with hot water and a good "slug" of Simple Green. Turned on the heat and ran it thru 2 cycles of the cleaner. Pulled it out and it was almost like new. I completed the cleaning of the terminals with the soldering iron, which brought out a little more wax/tar around the rivets. So I dropped it back into the cleaner and ran it thru another 8 min. cycle. This time it came out absolutely clean.
The tone control was next to go into the cleaner, after removing the potted caps. Again, it came out clean, looking like new and ready for rebuilding. I don't know if anyone else has tried this, but it sure worked for me.
I have re stuffed many of the Bakelite blocks, but this radio is the worst I have ever seen. I have not had the need to clean them up before. Just cut the leads, apply a little heat and pop out the old potted cap. Easy! But this does pretty good. Looks much better.
Chris H
N9WHH
