I have a technical manual for the Broadcast Audio Corp System 20 Console.
I also have info on the power supplies.
They use 2 power supplies, originally built as 24 volts at 3.6 amps but modified down to 18 volts each.
The 2 power supplies are made by Power One, part # HN24-3.6-AG. DigiKey has many in stock at about $73 each. Now the notes I have is that they are modified down to 18 volts from 24 volts by adding a 5K6 (5600) ohm resistor somewhere in the supply. Looking at it closer, there is a 5600 ohm small 1/2 watt or smaller resistor in parallel directly across a resistor. The component number of the resistor it is parallel across is hidden by the 2 large electrolytics above it, but it is the third resistor up in line from the negative (-) output terminals and under the filter caps and next to a metal trimpot marked R11 V ADJ. Also it is next to C4 a ceramic cap and just before R13 and U1.
You take two of these supplies to make + and - 18 volts.
A datasheet on the original 24 volt supply is here:
http://www.power-one.com/resources/products/datasheet/lin.pdf
A parts page link from a distributor is here:
http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail?name=179-2347-ND
Funny thing is these listed for $73.10 back in July 1996 and are now $72.83 each in 2008.
I have a 23 page Tech Manual for the console which specs out line diagrams, instructions and things like jumper settings plus installation, operation & maintenance sections.
Email me your email address to <ontheair247(AT)verizon(DOT)net and I will scan off a copy to you or anyone else needing same.
This would probably be a good addition to one of the broadcast manual archives somewhere too.
George Kowal CBNT
WRKL - AM