Cord drive tuning systems back in the old days could have extremely complex threading. e.g. the direction and number of turns round a shaft or pulley and whether the turns were wound upwards or downwards tended to be critical. If you got it wrong, the drive would tend to slip or jam, commonly towards one limit or the other of its range. It could also judder due to the incorrect lead angle causing one turn to pile on top of another then slip off again as it starts to jam.
The first rule of successful rethreading is: If you don't have a clear threading diagram from the service manual, preserve *ALL* evidence of how it was originally threaded before doing *ANYTHING* else to the receiver. e.g. photo whatever remains of the original cord, closeup and from several angles. Count turns remaining on all shafts or pulleys, noting direction and for multiple turns, which side is on top. Look for marks in dust, wear patterns, cord wear etc. that may help resolve ambiguities. Also examine the tensioner mechanism very carefully to see is there is any evidence of its original position, and measure the exact length of the cord to the break either side and the position of anything fixed to the cord (e.g. pointers) so you can check the length of the new cord to be certain you haven't got too many or too few turns around any shaft or pulley.
Home
Help
Search
Login
Register
