[AMPS] High-SWR protection

measures 2@vc.net
Mon, 30 Oct 2000 09:16:47 -0800


>
>> I'm sorry to hear this.  All I can say is that I also have two Bird
>> wattmeters and an assortment of slugs; and the first thing I'll do when I
>> get a VFD is to check it against the Birds.  If it's inaccurate I'll send
>> it back and hope they'll make it right.  In any case, I'll report my
>> findings to the AMPS reflector!
>> 
>> Thanks for the heads-up.
>> 
>> 73 de Chuck W1HIS
>
>A Bird meter is + or - 5% of full scale anywhere on the scale, when 
>calibrated within factory specs.
>
>With that in mind, if you are using a 2500 watt slug to read 1500 
>watts the actual power can be 125 watts high or low of 1500 watts.
>
>I have seen many Bird meters that were out of spec also. So be 
>careful that your Bird (or Birds) is not off. They are by no means 
>absolute standards.
>
Also, if the termination is not 50 +/- j0 ohms, all bets are off.  Before 
placing faith in any any power measurement, measure the DC resistance of 
the termination with a DMM.  

end

-  Rich..., 805.386.3734, www.vcnet.com/measures.  
end


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