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Realistic Receiver STA-21 from 1983,schematic or info on power supply secondary voltage

Hello everyone,I have a sta-21 receiver and I either need a schematic or if someone has one and can do tests for me then that would be good enough.All I need to know is the voltage on the secondary of the power supply transformer,it has two reds and a blue...the two reds would be the full voltage and the blue would split the AC in half,or goes to ground..thanks very much..simply email me with the sta-21 in the topic,,have a nice day