Interesting thread. I had two pairs of Infinity 2000A speakers (stacked) and was unaware until I sold them of just how many RTR tweeters had quietly died. There were 4 of the blue RTR panels in each speaker, arrayed in a vertical line with the top one tilted, as I recall. I ended up selling them for next to nothing because nobody I queried at the time could tell me how to bring them back to life. I doubt that there were more than 3 tweeters (out of 16) still working at that time. No, I didn't play the speakers especially loud.
RTR esr 15 info
I'm new to this forum and others after getting my eqpt. out of storage. After researching the RTR esr 15's I wanted to refurb. I have some needed? info on these. I have a schematic of the esr 6/15's and some reprints? I've cleaned and brought up the esr 15's on a variac, tested and updated MY version of the schematic I have.I then made my esr 15's a line source speaker to "go with" my Maggie 1d's. I have great pics of the final speakers,don't know how/if I can post these here? I saw a old pic of someone who did this "line source arrangement" but it wasn't pretty. Some hints for the blue elements (panels)...Hold the bottom (jam nut) nut while tightening/loosening the top nuts. You don't want the threaded post to rotate. The center post is slotted on the side opposite from the nuts side so you can use a small screwdriver to keep this post from rotating (on my panels at least).My elements are date coded 1974 as I recall. I used a super soft artist "fan" brush w/a fan blowing across me while dusting both sides of the "grids". I used those magnifier goggles you see the watchmakers/hobbiest use. This was time consuming for 30 esr panels, but the safest/most thorough way I felt. I could examine the grids and even straighten any "bent" grid/stator? wires I found.