Warwick Pro Fet II - Page 8

2.3Poweramp Testing/Regulating
Thereshouldbenolimitingoftheoutputsignaluntilthe
inputsignalreachesaround1,6V(peak-to-peak).
Iftheinputsignalisincreasedbeyondthispoint,somelimiting
oftheoutputsignalshouldbeobservableontheoscilloscope.
Frequencylinearity
Ground/Lift
Thefrequencylinearityistestedusingatonegeneratorandvoltagemeter.Theinputsignalis
connectedtothesocketontherearpanelofthe.Forthe
measurementtobecarriedout,itisessentialthatthesignalbevariablebetween
100Hz...1kHz...10kHz(switchedissufficient).Aloadresistanceof4ohms(250W)anda
voltagemetershouldbeconnectedtotheoutput.A1kHzsignalshouldthenbedirectedtothe
andthecontroladjustedsothatanoutputsignalof28V(peak-to-peak)(10
Veff)ismaintained.
Thefrequencyoftheinputsignalshouldbeswitchedto10Hzandthento10kHz.Thevalu e
oftheresultantoutputsignalshouldnotdeviatebymorethan10%fromitsinitialvalue.
Finallythefunctionoftheswitchshouldbe
checked.Forthispurpose,amultimetershouldbeswitched
betweentheearthsofthechassisandthedevice(Interior
partition-(Minus)).Theresistancevaluesfor
thesettingofthearesetoutinthenearbytable.Thevalueintheposition
canvarywidelyasaresultofthetransientresistanceoftheswitchingcontacts.Consequently
valuesupto5ohmsarepossibleandnormal.
EffectsReturnProFetII
EffectsReturn
Ground/Lift
SpeakerOut
Ground/LiftGround
Input Output
1,6Vss
1kHz
ca.:96Vss
34V
1kHz
4
eff
Ω
Ground
Lift
0Ω
1M Ω
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