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Old 5th Jan 2015, 1:58 pm   #1
vu2nan-nandu
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Default Handy 1 kW HF Dummy Load

Test equipment from the kitchen!

http://nandustips.blogspot.in/2011/0...ummy-load.html

73,

Nandu.
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Old 5th Jan 2015, 2:59 pm   #2
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Default Re: Handy 1 kW HF Dummy Load

Keep talking loudly and you have an SSB cup of tea. It shows what an inventive bunch we are.
 
Old 5th Jan 2015, 4:43 pm   #3
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Default Re: Handy 1 kW HF Dummy Load

The spiral element in the sheath will make the impedance vary quite a bit with frequency and it will also behave like a delay line making the power factor vary too.
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Old 6th Jan 2015, 12:01 am   #4
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Arrow Re: Handy 1 kW HF Dummy Load

Quite true Refugee, but he does say "The amplifier was successfully tested, with its Pi tank circuit providing a proper match to the dummy load".

Provided the output capacitive reactance of his Pi tank is adjusted so as to make a conjugate match with the inductance of that spiral element and provided that the resultant resistance is then 50 Ω, he should be O.K. For that condition, the P.F. will be unity. The Pi tank will need re-adjustment for changes of freq. though.

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