[Test-Equipment] Bird Termaline Question - Update (long)

[Howard Weeks]

Back around 1962 or so, I came by a 500 watt Bird Termaline load. 
According to an ohmmeter, it was reading high - well over 50 ohms but 
less than 100. I do not remember exactly what it was.

I stood the load on it's back end, loosened the clamp ring and removed 
it from the case. Lost a little oil in the process. The problem was a 
crack in the load resistor up near the top or feed point end. Since the 
coating on the resistor was conductive, I put a small stainless radiator 
clamp (about 1/2" wide) over the crack and tightened it. The resistance 
went to about 49 ohms or so and I put it back together with a little 
additional mineral oil. I still have that load and it is still working. 
The slightly low resistance doesn't make any practical difference in the 
normal use of it.

Howard K5JCP in GA

On 2/7/2017 2:15 PM, Richard Knoppow wrote:
>    Since you got into the thing is is possible to measure the resistance
> of the resistor directly?
>    What I suspect is that the resistor is not really a single resistor
> but effectively several resistors on parallel. This is done by taking a
> coated blank resistor and slitting the coating lengthwise into several
> sections. If one burns out the value goes up by an amount which depends
> on the value of each section. I think they may open at one end rather
> than actually opening along the length somewhere. The cartridge
> resistors used in the Cantenna and in the MFJ look identical. Both have
> a coating over the resistor coating and silvered end sections for
> connecting.  It is not possible to see the internal connections.
>     I don't know who actually makes the resistors but have found similar