RT, Good point. But it can be done on many 78 rpm record changers. Again, I’m not familiar with the Philco 46-1226, but I betcha this too can be made to work reliably. Each of these record changers has a personality of its own and will probably require some tweaking to initiate the trip cycle at end of record. I've had good luck with a few solutions. First, if the record changer has a ‘velocity trip’ also called an acceleration trip, which initiates the record change as it relies on the change in speed of the tone arm as it moves toward the spindle, at end of record, the 78 run-off groove (if there) will drive the tone arm toward the spindle quickly. This sudden change in speed initiates the trip, not a problem for the ceramic cartridge/stylus.
Some velocity trip mechanisms will initiate the change cycle if the tone arm moves forward more than 1/4 - 1/2 inch during one cycle. Some changers rely on the drive pawl, (looks like flat gear) which slowly moves forward synchronized with the main gear, as the drive pawl moves forward slowly, it will trip a spring loaded flange which initiates the change cycle on the next revolution. This is reliable only for 10 and 12 inch records and they must have a run out groove.
There’s an eccentric trip (sounds like bad weed) really an oscillating trip mechanism that actuates the change cycle when the needle tracking in the run off eccentric groove causes the tone arm to move backward away from the spindle. This backward movement can jump the groove and thus fail to trip, if this happens try adjusting the eccentric stud adjustment by turning it clockwise. Sometimes changing the spring that puts tension on the trip finger (a ball point pen spring, cut to length) will do the trick.
Even the RCA Victor RP-190 which is pretty gentle and was engineered assuming a wide run-off groove on the 45 rpm record, may need adjustment. I always lighten the weight of the cycling cam by drilling 14 holes and I always rebuild this cam using a neoprene washer (rather than buying a replacement or using that grooved piece of window rubber that is found on eBay. Needless to say, I’m looking for flawless operation and as the weight of the tone arm can be modified, we have to be creative about adjusting what actuates the trip. Look closely at the stylus in a ceramic cartridge and you’ll see there’s a pretty hard horizontal movement when you trigger the change cycle by pulling the spring-loaded reject button; this is why the stylus should have a good rubber yoke and metal (not plastic) cantilever.
Finally, I never, ever use grease on any friction points associated with the change cycle, a light oil lubrication is sufficient. Have fun.
Please see: http://phonojack.com