|Decca London ribbon tweeters with huge transformers.
|The horn of a Decca ribbon tweeter
|Brass mess behind the horn,
|These have large, powerful magnets
|Old ribbon (left) and new one waiting to be soldered.
The ribbon material in these speakers is stiffer and thicker than one would use in a microphone. The thickest foil I had in stock is 6.5 micrometer thick, supplied by Advent Research Materials, so that is what is going into these. That is about three to four times thicker than would be used in a microphone. The gap is 10mm and I cut the ribbons at 8.6mm, based on measuring a 'good' ribbon. Corrugating is routine, but the challenge here is making the electrical connection from the ribbon to the mounts. There are no ribbon clamps but I can see traces of old solder.
|New ribbon in position.
|New ribbon as seen through the horn.