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Re: [Amps] Advice needed for SS amp

 To: amps@contesting.com Re: [Amps] Advice needed for SS amp Manfred Mornhinweg Fri, 07 Jun 2013 02:08:14 +0000 mailto:amps@contesting.com>
 ```Larry, Jim, ``````Any one want to check my math? `````` I checked it, and Larry is right. ```A half gallon of water (1893 milliliters), which has a specific heat of roughly 4.19 joule per milliliter per kelvin (the actual value varies slightly with temperature), heated for 5 minutes (300 seconds) with 1500 watts, would warm up by ``` 1500 * 300 / 1893 / 4.19 = 56.7 kelvin, ```which is the same as 56.7 degrees Celsius. Hardly enough to make it boil, unless it was pretty warm to begin with! ``` ```Starting from typical tap temperature, and considering some loss that ends up heating the kettle and producing some steam, the actual time required for boiling would be somewhat between 7 and 8 minutes, assuming the power is actually 1500 W and the water volume is actually half a gallon - and that the water is pure, not mixed with some liquid that has a lower specific heat! Now I don't think that anyone will boil a water/glycol mix to make coffee, but it's very possible that the heater actually is consuming more than 1500 W, or that the amount of water is somewhat less than half a gallon. ``` ```This illustrates that cooling a legal limit amp with a bucket of water under the operating desk is a satisfactory method for casual operation in SSB, but won't cut it for a full weekend of RTTY contesting! ``` Manfred ======================== Visit my hobby homepage! http://ludens.cl ======================== _______________________________________________ Amps mailing list Amps@contesting.com http://lists.contesting.com/mailman/listinfo/amps ```