[AMPS] Input power question

[measures]

>
>Hi All,
>
>Just a quick question after experimenting with a couple radios here the last
>couple days.  I have an AL-800H amp (two 3cx800a7) and 2 different exciters,
>an FT-990 and an IC-756.  I am curious why it takes 80watts from the Yaesu
>and only 55 watts from the Icom to drive to a 1500 watt carrier.  I have put
>a wattmeter between the radio and amp and the amp and antenna.  I assume its
>some kind of impedence thing, perhaps from the finals of the radio.  Both
>radios at 100watts out will drive the amp to the same output.
>
>I am not that concerned about it, even though the amp is rated at legal
>limit for 55W of drive, 25 watts seems like quite a large difference to
>achieve the same output.  The input SWR is < 1.5:1, but the Icom shows
>1.19:1 and the Yaesu shows 1.46:1.
>
>Any comments?

Wattmeters are worthless when swr exceeds 1:1.  

cheers.  

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


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