Actually, the viscosity (the number indicates viscosity, not weight or
density) is important. The lower the number the better. That's one of
the reasons transformer oil is better for transformers and dummy loads
than drug store mineral oil - it has lower viscosity. The lower the
viscosity the more easily convection currents transfer heat from the
dummy load into the fluid and from the fluid to the can. That means
lower thermal resistance, giving a lower resistor temperature for a
given power dissipation.

73,
Bob AD3K

BOB wrote:
is far motor oil (if you have to use it ) use "nd 30" (or 40 ,20,50 the
weight is not important) the "nd" is non detergent, to not dissolve carbon

i tend to agree try to find an oil closer to what's "right"

bob


--
Robert L. Spooner
Registered Professional Engineer
Associate Research Engineer
Intelligent Control Systems Department

Applied Research Laboratory Phone: (814) 863-4120
The Pennsylvania State University FAX: (814) 863-7841
P. O. Box 30
State College, PA 16804-0030