Gold Apollo AL-A28 (Pilot XP)
An obsolete pager can be converted into a single channel receiver for paging monitoring by adding a discriminator output.
With the Gold Apollo AL-A28 POCSAG pager (sold in the US as 'Apollo Pilot XP'), it is not necessary to solder at receiver IC, that has a high pin density.
Each pager contains a battery saving mechanism. At regular intervals, the receiver is switched on briefly to check if there are messages. If not, the receiver will sleep until the next interval. To be able to use the pager as a monitoring receiver, this battery saving mechanism needs to be disabled to open the receiver continuously. Obviously, as a result battery life will decrease considerably.
Follow the next steps to make a data output on the AL-A28:
Location of the solder pads
Connected solder pads and 10 k resistor
As there is not enough clearance for a chassis socket, you can drill a hole and lead the shielded wire outside. You can use a tyrap as strain relief. The shielded wire can be terminated with a female 3.5 mm connector. This 'pigtail' enables using an interface or audio cable.
You can also box the pager and add a 1.5 Volt power supply. You can find a description here.