30-11-2015, 04:47 PM
(27-11-2015, 11:29 PM)Crackle Wrote: Well done, it is surprising how difficult it is to find a fault like a little wisp of wire touching where it shouldn't.
It may be possible manufacturers fitted components into "modules" like your double tag strip, and then fitted these into the set. It may have saved time.
This is a component board in a radio I am repairing at the moment, I would not be surprised if this was assembled outside the set and then wired in. There is another row of solder tags for the other end of the component leads the opposite side of the board (which indecently is only made of cardboard) hidden under the rest of the wiring. But this method of fitting components is probably easier to work on whilst carrying out repairs than the tag strips you had in the HMV.
Mike
Was the tag-strip idea a good one? The way I see it maybe the manufacturers figured if a radio lasts 20 years, that's a fair innings. They probably never figured there would be a need to remove the tag-strip where most of the larger bypass capacitors were soldered in. However, on the HMV, it really was a nightmare. One day last week I was close to tears of frustration because I couldn't get a solder joint to hold. The solder point was deeply recessed to the point I needed a lamp shined on the joint to see where I was and the slightest movement would scorch nearby wires or components. It took half an hour to do the one joint whereas other joints after that took seconds due to better access.
Far better in my opinion not to use tag-strips unless some thought for access has been pondered.
I've often wondered about something, though, and it's a good question to ponder. How often did tube radios suffer a broken solder joint? What would happen if an HT lead at 230 VDC came off an HT can and then swung around till resting on the chassis? Would the fuse save the day and blow? Obviously there was no RCD back then and no earth wire. I often think there must have been incidents and the tag strip idea might have emerged due to that.
