I swear I had sent an email on this an hour ago...
Anyway, I replaced replaced the LM338 with a switching regulator. This one was very inexpensive, less than a dollar. It is also very efficient and small. Unfortunately, I dont know what it is called!
I am attaching the pictures. There is a tiny pot on it that controls the output voltage. I added a 22 ohms, fat resistor to the output pins and adjusted the output to 5.4v. Then I took out the LM338 and installed this. The ground is a thick and very short connection to a mounting hole (I used desoldering braid). The input and output is wired to the LM338's pcb holes.
I am running this for a while before declaring victory.
If someone can identify the chip and the regulator, I will be grateful.
