[Heathkit] Cantenna

[Ron Youvan]

> My question is regarding the resistor. I still have the original but 
> it now tests at 42ohms. Many years ago after the oil scare, I called a 
> friend at the power company and was given replacement transformer oil 
> of the type they had switched to.

   I must question the accuracy of your Ohm meter.  If you can find two one hundred Ohms, 1 percent 
(tolerance) resistors to put in parallel that should be a good calibration.  (or fifty 1 Ohm in 
series  HI  HI)

> Is it possible that the newer oil has had any effect on the R being 
> lower now. I have never used more than 100W to it and it has been kept 
> in the shack (house) all the time. The oil is kept within 1/2inch of 
> the top.

   I would think not.  I would NOT expect to see a lower resistance other than
some kind of coating (carbon?) in parallel with the resistor.

> I will replace the resistor as soon as I can find one that will fit. 
> Also, the lower silver plated clamp is broken so will have to find a 
> substitute. I know that Kanthal Globar has resistors but who else 
> does? I believe that the Globar 886SP rated at 90W would work. It is 
> the exact size of the original. Of course they are not copper or brass 
> like the original but rather aluminum contacts. It is hard to 
> understand their specs.

   My cantenna had what looked to me to be aluminum straps on the ends of the resistor and they had 
cracked.  (when mine measured 100 Ohms)

   Not in the same form, you can buy 20 to 50 Watt 50 Ohm non-inductive resistors that look like 
huge TO-220 transistors with only two leads, these could be mounted on some aluminum plates or 
pieces of angle aluminum supported in your coolant.  Putting two in series in parallel with another 
two would give you 4 times the dry dissipation.  (50 X 4 = 200 Watts)
-- 
    Ron  KA4INM - There is no time like the pleasant.