How about this?
Intent startIntent = new Intent("WhatEverYouWant");
PendingIntent startPIntent = PendingIntent.getBroadcast(context, 0, startIntent, 0);
AlarmManager alarm = (AlarmManager) context.getSystemService(Context.ALARM_SERVICE);
alarm.set(AlarmManager.RTC_WAKEUP, triggerTime, startPIntent);
And then in your Manifest.xml
file:
<receiver android:name="com.package.YourOnReceiver">
<intent-filter>
<action android:name="WhatEverYouWant" />
</intent-filter>
</receiver>
So as far as I know you still have to declare the receiver in the Manifest. I’m not sure if you can set it to a private instance inside of your activity. You could declare an onReceive inside of your activity and call that (if the BroadcastReceiver has an interface. I don’t know if it does.)