<under construction>
For sure, procedure is rather close to refurbishing bass panel. Just more complex.
Tip: do not repair what is not broken
This one needs to be repaired !:
What you hear: http://esl.drakkapps.com/wp-content/uploads/2020/01/IMG_5585.mov
What you see: http://esl.drakkapps.com/wp-content/uploads/2020/01/IMG_5586.mov
Some measurements
Just a sanity check. With one probe on long red wire (polarisation of diaphragm), resistance from this wire to all other ones will be > 500MOhm (no leakage), whereas capacitance will be approximately 180pF with blue wires (medium) and 150pF with brown wires (center, treble). If you cell has arced, you will not get this information from this basic check.
Dust covers
Same procedure as for dust cover for bass panels. A reparation is sometimes possible when wrinkles are visible. See below, using a heat gun set at 100°C.
Open cell
Use a plier to squeeze the head of the rivet in one direction then in the other. Cut the head (wear glasses !) then push gently and remove the other part of the rivet from the other side. Plan for 45min to remove 56 rivets (vs about 66 for bass cells).
Note for refurbishers: treble cells are 4.4mm thick, rivets have a diameter of 3.2mm. M3x6 screws and low profile nuts (1.8mm) are adequate as replacement: this is what I use. If rivets are preferred: 4.4*1.1+3.2*1.5=9.64 : 3.2x10mm can be tried. For bass cells: M3x10 / 3.2×14.
Tip: do not remove the 2*2 rivets that are used to power the diaphragm (red wire)
Tip: use low profile bolts to avoid changing overall thickness of the cell
New wires: long enough to be confortable to solder the audio input transformer:
- 44 cm for the 2 blue ones
- 35 cm for the 2 brown ones
- 64 cm for the red one
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