Re: Voltage Regulators or Diodes to drop voltage?

You can buck the primary winding voltage with another yet much
smaller transformer.
This is an easy quick yet reliable fix.
Example: If you would like to lower the supply voltage by 10%...
Lower the Primary voltage by 10% or that would be 10% of 120 volts =
12 Volts.
Get a 12 Volt transformer rated at or more than your maximum primary
current.
Yes the Primary current, not the secondary current.
You mentioned your pulling 7 ampers, so the primary is probably 2
amps max. ( 1.6Amps = 7 / (120/28) ) (I'm assuming your secondary is
28 Volts)
Ask for a 12 Volt/2 Amper "filiment" tranformer at your local TV Shop.
This is a small and inexpensive unit.
Wire the primary to the 120V as normal and wire the secondary in
series with the primary of your Power Supply Transformer.
Measure your output again.
If it is 10% higher... swap the leads on one of the Filiment
Transformers windings.
Now you should measure 10% Less.
See how that works... Simple reduction without waisting power.

Tom M.