[DMcMahon]

First attachment is a section from a Roberts 1725 Reel to Reel tape recorder schematic. This shows 4 capacitors and 2 resistors within a dotted line box identified as "35-09 P.A.C. Unit". This looks to be part of the Bias Oscillator circuitry. The second attachment is a close up of the dotted box area.

I saw this when comparing the 1725 schematic to the Akai 1700 schematic, the Roberts 1725 recorder being derived from the Akai 1700 recorder. The Akai 1700 schematic shows very similar components/connections but not within a dotted line box/not identified as P.A.C. Unit.

So have been racking my brains trying to work out what P.A.C. could be an abbreviation for, any ideas please ?

David