I have spent a happy weekend in the shed playing with a box of dead altette horns and actually managed to get them working (although they still make a sound more like a surprised duck than anything that would be of use out on the road).
I was wondering what the deal is with the gaskets and what one is trying to achieve by adding or taking away gaskets?
It seems that, provided all the components are OK, you can do all the necessary adjustments (armature to coil air gap and push rod adjustment) with the respective screws and nuts. Are the gaskets providing clearance or maybe damping / isolating the diaphragm from the horn body?
And the adjustment screw for the points seems to just tilt the contact assembly but I couldn’t see if it actually separates them at all. Does it just alter the tension to open them, or the separation to the pushrod?
chuffed that I got them to work at all but still wish I knew exactly what I was doing!!
To many gaskets will move the diaphragm further away from the magnetic pull of the coil and to close can cause the diaphragm to bind on the rim. This is what I have found when trying to adjust them.
And one more thing. The diaphragm is dished, so which way should it be installed. I have read other descriptions of this but the terminology is different every time so I’m still confused and can’t seem to come to a clear consensus. This would also affect the airgap unless you adjust that from the rear.
To make it clear, even to me, should it be installed so that my tears of frustration collect in the bowl of the diaphragm or so that they run off? :sob: