Re: Low Cost Dummy Load


David Martin <davemrtn@...>
 

Yes but, as you can see from his photo, he paid for a 1% resistor !!

For $11 (+ shipping), I would be calling the vendor.

OR MAYBE, the error is in the device he is using to measure the resistance ??


On 5/11/2015 2:05 PM, Wayne Dillon wayne.dillon@... [4sqrp] wrote:
 
Hi Darryl
Should be 2K2, this equates to 50.0355 Ohms total effective resistance. Not sure on power as the 51.2 is only about 3% of the 2K2. Anyway why worry about the error? the error is less that 3% and that's better than most commercial dummy loads.
Just my $0.02 worth.
Be blessed
Wayne - KC0PMH

On Mon, May 11, 2015 at 1:49 PM, kk5ib01@... [4sqrp] <4sqrp@...> wrote:
 

This is my new low cost dummy load, made with a Caddock thick film non-inductive resistor. This one is 50 ohms at 1%, and rated at 100 watts, and costs about $11.00 from Mouser or Digikey. I realize the current heat sink will not be adequate for 100 watts, but it will suffice for the 5 and 50 watt calibrations of my K3, it does get warm to the touch. Only problem is resistance measures 51.2 ohms. What value of a parallel resistor would bring that down to 50 ohms? I calculate 1234.56 ohms or 1.2 K. Is that right? Also what would the power rating of the resistor need to be? Thanks.

Darryl, KK5IB




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