MagneQuest PGP 8.1 power transformer installation
1. First apply a drop of acetone to the nut of each corner of the transformer. Be careful not to use more than a drop or two, as the acetone will soften the varnish finish on the transformer laminations if it slops over onto them.
2. Let the acetone work for a few seconds, and then carefully loosen the nuts, one by one, using a slotted tip screw driver of adequate size to avoid damaging the screw’s slot, and an 11/32” socket wrench. Remove the screws using some axial pressure to keep the screwdriver from skipping from the slot, and keep track of the order of the placement of the washers as they come off.
NOTE: once the screws are removed, be very careful with the transformer! Damage caused by dropping the transformer and knocking laminations apart is not covered under warrantee !!
3. Next install the bell end and replace the screws, following the original order of the placement of the washers. Before tightening snugly, place the transformer into the mounting holes in the amp chassis to make sure they are properly spaced. Then remove the transformer and tighten the nuts snugly, but not so tight as to stress or deform the laminations.
Your PGP 8.1 is now ready to install.
The terminal identification of the PGP 8.1 is as follows:
1S start of the 700VCT ( a.k.a. 350-0-350V) 75 mA secondary winding
1T 700VCT secondary center tap
1F finish of the 700VCT secondary winding
2S start of the 115V primary winding
2F finish of the 115V primary winding
3S start of the 6.3V 2A secondary winding
3F finish of the 6.3V secondary winding
4S start of the first 2.5V 1.25A secondary winding
4F finish of the first 2.5V secondary winding
5S start of the second 2.5V 1.25A secondary winding
5F finish of the second 2.5V 1.25A secondary winding
For a 2A3, 45, or other 2.5V filament connect 4S to 5S and connect 4F to 5F for a 2.5V 2.5A filament supply. Connect one end of the tube filament to 4S and 5S, connect the other end of the filament to 4F and 5F.
For a 300B first connect 4F to 5S, and then connect one end of the tube filament to 4S and the other end to 5F for a 5V 1.25A filament supply