[Test-Equipment] Bird Termaline Question

[Ron Youvan]

   On 02/04/2017 09:11 PM, Brian VK2GCE wrote:

> Time to get a few facts rather than armchair hypothesising, as
> entertaining as it may appear.

> 1. The only way to test a dummy load is with RF. A DC resistance
> measurement only speaks to connectivity.
  /* snip */

   If the resistor is not the desired resistance with a dc measurement
it can't be the desired resistance with an ac measurement.

  /* snip */
> 9. What Bird does not say is that the negative exponential tube is
> slotted to allow free oil flow. Most illustrations show Bird Termaline
> units horizontal. Heated oil loses some density and, on the Earth's
> surface, rises = convection. To get the longest life out of your
> Termaline, I suggest you use it vertical.* The heat radiating fins on the
> outside don't really care about Earth's gravity.
  /* snip */

* Bird oil cooled loads are in a tank that are never completely full to
allow room for expansion, if you operate them vertically you could be
operating the resistor partly not submerged (overheating that portion
of the resistor) and the air rising from the hot fins will not be able
to rise along the fins as well with the fins horizontally positioned.
-- 
   Ron  KA4INM - Youvan's corollary:
                 Every action results in unwanted side effects.