[Boatanchors] Carborundums

[Brian Clarke]

Hi Pete,

I've been down this path many times. I used to teach Broadcast Engineers how 
to construct good dummy loads on which they could rely forever!
1. Heath with its Cantenna used a perfectly good carbon cylindrical resistor 
and buggered the application by using a straight , rather than inverse 
logarithmic, cylinder around it. Look at any Bird Termaline to get an idea 
of what it should be like.
2. Cooking oil is a no no - it has the wrong characteristics, and certainly 
is not characterised for any, let alone constant dielectric properties.
3. Visit almost any electricity distribution authority and ask for a couple 
of litres of transformer oil -  they will probably give it to you - they do 
in NSW.
4. Epoxy over the surface of the carborundum will alter both the heat 
transfer and dielectric properties in ways you cannot know in advance.

73 de Brian, VK2GCE.