.66 ohms, determined by four terminal measurement of .657 volts across coil component side solder joints while one amp was flowed thru PC solder side terminals.
Most people with this problem already have perfectly good copper windings on perfectly good coil forms, once that pesky but quite brittle stuck core is removed. One approach is to cut away the exposed form in various ways to allow an intact but stuck core to be grasped and twisted out to be cleaned and reused. Another approach better for already fragmented cores is further mechanical fragmentation by controlled violence. A nail with the end reshaped like a cold chisel should work, with the analog board removed well away from the CRT. If the fragments can be made small enough they could be shaken out and it may be unnecessary to do any plastic cutting at all. If you or others could find a suitable source for powdered iron cores of sufficient permeability, one or two could then be threaded in to the existing coil to repair it.
I don't know the sweep rate offhand but it's in the Guide to the Mac Family Hardware book. I think getting enough permeability will be the powdered iron core selection issue, not the core losses at the several harmonics of the sweep ramp (but it can't be solid or laminated transformer iron, and I am uncertain if ferrites of the manganese-zinc will saturate in this application).
Most people with this problem already have perfectly good copper windings on perfectly good coil forms, once that pesky but quite brittle stuck core is removed. One approach is to cut away the exposed form in various ways to allow an intact but stuck core to be grasped and twisted out to be cleaned and reused. Another approach better for already fragmented cores is further mechanical fragmentation by controlled violence. A nail with the end reshaped like a cold chisel should work, with the analog board removed well away from the CRT. If the fragments can be made small enough they could be shaken out and it may be unnecessary to do any plastic cutting at all. If you or others could find a suitable source for powdered iron cores of sufficient permeability, one or two could then be threaded in to the existing coil to repair it.
I don't know the sweep rate offhand but it's in the Guide to the Mac Family Hardware book. I think getting enough permeability will be the powdered iron core selection issue, not the core losses at the several harmonics of the sweep ramp (but it can't be solid or laminated transformer iron, and I am uncertain if ferrites of the manganese-zinc will saturate in this application).