[QRO] plans still needed

[Galen Watts]

Cutting to the chase...

Resistors of the type you're seeking (at least for an RF load) are 
usually called 'carbon tubular non-inductive' and end up sunk in a 
mineral oil or transformer oil bath, just like my Heathkit Cantenna.
The Cantenna is essentially a 50 ohm resistor sunk in an oil bath in a 1 
gallon paint can with a coax connector in the center of the lid.  It can 
handle 1500 watts for a short time or lower powers for longer.  There's 
a curve on the can to show how much power for how long.  I think MFJ has 
a load similar to the cantenna.  Surplus Sales of Nebraska and Fair 
Radio Sales may have the tubular resistors.

The guts of the cantenna consist of the tubular resistor connected to 
the coax center pin at one end, dipped into the oil vertically and the 
other end connected to a sleeve surrounding the resistor and connected 
back to the can lid with slots to allow the oil to freely circulate.  It 
may attempt to approximate a 50 ohm coaxial line with the resistor in 
the sleeve, I never really worried that much about it.

We have a large wire wound resistor for loading down power supplies, it 
just sits out on the bench (and gets dang hot), we don't have it in a 
cooling bath but we also don't run it for very long.

I hope that helps, your wattage/mileage may vary.

W8LNA

-- 
Galen Watts
RF Engineer
National Radio Astronomy Observatory
PO Box 2	(or)	Route 28/92
Green Bank, West Virginia 24944-0002
http://www.gb.nrao.edu/
304-456-2134
304-456-2200 fax