----- Original Message -----
From: "Jim Lux" <jimlux@earthlink.net>
> Mineral oil and Transformer Oil (i.e. Diala AX) ARE the same thing... The
> MSDS for Diala AX says that it is mineral oil (more precisely: highly
> refined petroleum oils).
>
The are nominally the same, but I am not sure that I would
want to use Diala-X or gear oil as a laxative :) From the bit
of googling I did this afternoon, it seems that mineral oils are
all nominally composed of what are termed "hydrotreated
paraffinic distillates". Of course, even paraffin itself seems
to be pretty vaguely defined (e.g. its not just a simple
unambigous compound like H2O).
In any case, there must be some difference in the net
thermal performance. Whether it's soley a matter of viscosity
differences, or some difference in the chemical makeup, I
don't know (I almost failed chemistry in college). Either that
or the derating curves on the MFJ and Heath cantennas are
just wrong.
> $25/gallon for the real thing is quite high... Unless it included shipping
> and tax, considering you can buy 5 gallons for under $30. Somehow, I
doubt
> MFJ is going to certify the water/contaminant content, as delivered, too.
Yes, $25/gallon is pretty darn outrageous, but then again it's
easy to get (UPS drops it on your front porch) and 1 gallon is
a lifetime suppy for most hams. Not sure the water content
matters much for a dummy load since the voltages are
relatively low, whereas I here it matters greatly in HV
applications. For more than one or two dummy loads, the
extra trouble of finding and traveling to an oil jobber starts to
make good sense.
73 de Mike, W4EF......................
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