Not knowing the innards of the Cantenna, may I suggest a quick test for
the usefulness of simply a bigger can of oil. The test would be to see
if the sides of the existing Cantenna are warm after the "10 or 20
seconds" at 2KW claimed to be the maximum before VSWR change. If the
outside of the can isn't warmer than before the test started, then a
bigger can filled with more liquid will not help. It would seem that
one would have to get the oil circulating around the resistor better to
justify a larger reservoir. My guess is the can surface will NOT be any
Is it true that the Cantenna's VSWR changes appreciably after 10 to 20
seconds of 2KW?
> >> The Cantenna dummy loads just can't take 1.5 Kw for
> >>very long. ........
> >You can use a 5 Gallon can which are usually throw aways from auto
> >With some creative work with tin shears, drill, and a propane torch
> >can adapt the Cantenna as a unit.
> >Thoroughly wash out the solvents in the can first!
> >With 5 gallons of xfmr oil you can run 2KW for at least 20 minutes
> >still maintain the Cantenna frequency response.
> ? With a resistor that is spec'd at 100 or so watts, this solution
> sounds somewhat unlikely. If transformer oil vapour-bubbles begin to
> form on the surface of the resistor, which seems quite likely, it does
> not matter if the resistor is in a 55-gallon drum or a 1-gal. can of
> stuff. .
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