Re: ALC Problem

Pasquale S

Hi Paul, thanks for your answer


It’s no a problem related to temperature, RF power goes up slowly, very slowly about 5 seconds to arrive 100 watt !!! This is the first time, then it’s faster.


In VHF and UHF there is no problem, so I suppose there is no problem with pre-driver and driver, everything runs well.


IN HF/50 I changed RD70HHF1 because I had a fault before; in your opionion, can RD70HHF1 be the problem ???? Vth is about 2 volt, it seems too little value.




Pasquale IW0HEX



Inviato da Posta per Windows 10


Da: Paul
Inviato: domenica 19 luglio 2020 03:32
Oggetto: Re: [ic7000] ALC Problem


Hi Pasquale ,

In what time frame does it go up? , is it slowly or fast , could it be a temperature related thing as something needs to be warmed up .

I think you'd need a oscilloscope to investigate the drama to see where the slow increase is actually happening RF wise like at the pre-driver or driver or even before that as being new finals i doubt if the issue is from there .

Also i'd be checking around the power setting dc rail for any variations but the Cro would be far quicker (if you have one) , 73 Paul .


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