10-24-2016, 10:17 PM
The problem with these particular caps is that they are really buried within the band switch. The other wax/paper caps in the RF chassis are relatively easy to get to, once the chassis is removed. There was one where I resorted to the "twist until it breaks" method and was able to splice the new cap in place. These were relatively easy, as compared to the two within the switch, itself. These are caps #9 (connected to B3 on the wafer switch), and cap #28 (on terminal E3 of the wafer switch). These guys are really buried and almost invisible from all angles, even with the chassis and side plates removed.
Well, I was able to replace the caps by, carefully, cutting off the rivets holding both 3-gang trimmer caps that are attached to the divider plates separating the 3 sections of the chassis. I disconnected the trimmers from the coils and removed them completely from the chassis. I used a small rotary file in the Dramel tool to cut the heads off the rivets, and was careful that the chips fell outside the chassis.
I placed a long length of spaghetti tubing on the new cap lead, and formed a hook on the end, carefully wrapping the lead around the switch terminal as best I could and carefully soldered in place. I positioned the new cap outside of the band switch. Then cut off the chassis ground lead from the old cap as close as I could cut it off. (I just left the old caps in place. I could see no means of removing them without damaging something.) I attached the chassis ground lead, with a length of spaghetti tubing, to the same chassis terminal as where the old cap lead was attached.
I reattached the 3-gang trimmer caps to the original mounting position on the dividers with #4-40 fasteners and lock washers. Then re-attached the coil and switch leads to the trimmers. It was really not as bad as I thought it was going to be. I have yet to reinstall the chassis, as I am waiting on new cloth insulated wire to replace the chassis leads to the main chassis. Some of these leads can be reattached through holes in the top side of the sub-chassis, under the tuning cap. Some are relatively easy to get to from the sides, and some will just have to be spliced, as they are just not in a position to get to.
The big question is, is it going to work afterwards???? I usually replace one or two components at a time, and test, just to make sure I have not flubbed up somewhere, but in this case, that is not an option. Hopefully this may help someone else out when they go through the same thing. It may not be the right way, but it is the method that worked for me.
Thanks for the advice.
Well, I was able to replace the caps by, carefully, cutting off the rivets holding both 3-gang trimmer caps that are attached to the divider plates separating the 3 sections of the chassis. I disconnected the trimmers from the coils and removed them completely from the chassis. I used a small rotary file in the Dramel tool to cut the heads off the rivets, and was careful that the chips fell outside the chassis.
I placed a long length of spaghetti tubing on the new cap lead, and formed a hook on the end, carefully wrapping the lead around the switch terminal as best I could and carefully soldered in place. I positioned the new cap outside of the band switch. Then cut off the chassis ground lead from the old cap as close as I could cut it off. (I just left the old caps in place. I could see no means of removing them without damaging something.) I attached the chassis ground lead, with a length of spaghetti tubing, to the same chassis terminal as where the old cap lead was attached.
I reattached the 3-gang trimmer caps to the original mounting position on the dividers with #4-40 fasteners and lock washers. Then re-attached the coil and switch leads to the trimmers. It was really not as bad as I thought it was going to be. I have yet to reinstall the chassis, as I am waiting on new cloth insulated wire to replace the chassis leads to the main chassis. Some of these leads can be reattached through holes in the top side of the sub-chassis, under the tuning cap. Some are relatively easy to get to from the sides, and some will just have to be spliced, as they are just not in a position to get to.
The big question is, is it going to work afterwards???? I usually replace one or two components at a time, and test, just to make sure I have not flubbed up somewhere, but in this case, that is not an option. Hopefully this may help someone else out when they go through the same thing. It may not be the right way, but it is the method that worked for me.
Thanks for the advice.
Chris H
N9WHH