18-04-2014, 08:30 AM
The latest photo's are interesting Trev, when I saw the first set you posted showing the slot only from the top I thought that there might have been an adjustable pole piece that poked up through it that was missing.
Having now seen the rest of the innards I cannot see were it would have been attached to the screw adjusting mechanism, so it might be that nothing is missing? The fact that the slot is tapered is also interesting and I am wondering if it is shaped like that to concentrate the magnetic field from the permanent magnet in the area of the reed.
You seem to have established that there is plenty of attraction between the pole piece and the reed, it's important that the reed does not have any contact with anything except at it's two fixing points and the rod to cone fixing point.
As for the other two screws with the springs that secure the brass plate/block to the main frame then they might be adjustable, possibly adjusting the tilt of the assembly with respect to the reed, the face of the pole piece (the one with the slot) needs to be parallel with the underside face of the reed and adjusted as close as possible to the reed without any physical contact between the two, the reed needs to vibrate freely.
Lawrence.
Having now seen the rest of the innards I cannot see were it would have been attached to the screw adjusting mechanism, so it might be that nothing is missing? The fact that the slot is tapered is also interesting and I am wondering if it is shaped like that to concentrate the magnetic field from the permanent magnet in the area of the reed.
You seem to have established that there is plenty of attraction between the pole piece and the reed, it's important that the reed does not have any contact with anything except at it's two fixing points and the rod to cone fixing point.
As for the other two screws with the springs that secure the brass plate/block to the main frame then they might be adjustable, possibly adjusting the tilt of the assembly with respect to the reed, the face of the pole piece (the one with the slot) needs to be parallel with the underside face of the reed and adjusted as close as possible to the reed without any physical contact between the two, the reed needs to vibrate freely.
Lawrence.
