To sum up..........
The Birotron in it's marketed form was a flawed design that was well engineered from a sturdy construction point of view (nice castings) but having taken one apart and rebuilt it from the ground up, the end result just didn't justify the effort and expense. The feel was poor, the ensuing noise was a grave disappointment. Low fi, azimuthy, noisy and pointless. Sad but true. Very collectable though.............just like Trabants!
M
........and I never want to lace two complete sets of Birotron cartridges EVER again!