On Wed, 3 Feb 1999 09:10:49 -0500 (EST) "William L. Fuqua III"
<wlfuqu00@pop.uky.edu> writes:
>
> The Cantenna dummy loads just can't take 1.5 Kw for
>very long. I was wondering if anyone has tried to
>cool one of these. Either by running water thru the
>can in a coil of copper tubing or maybe even having
>the water replace the oil and run it thru the can.
>I guess another possibility is to have oil circulated thru
>the can and cool it in an heat exchanger. Any ideas?
>I seem to be able to run 2KW into mine for at least
>a 10 or 20 seconds at a time with out any additional
>cooling. But not long enough for serious test.
>
> 73
>Bill wa4lav
You can use a 5 Gallon can which are usually throw aways from auto body
shops.
With some creative work with tin shears, drill, and a propane torch you
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 and
still maintain the Cantenna frequency response.
Adapting other wattage resistors is also quite simple if low VSWR at VHF
is not required; otherwise a rather involved method as mentioned in
several ARRL Handbooks is required.
73 Carl KM1H
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