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ludo schoofs <ludoschoofs@...>
 

Hi,

 

Can You remove this email adres: ludoschoofs@...

 

With the transition to from Yahoo to Groups.io I changed an adres. This, the old one,  kept receiving mails.

 

Thanks,

 

Regards

 

Ludo

ON7JW

 

Van: BITX20@groups.io [mailto:BITX20@groups.io] Namens Richie Chambless
Verzonden: donderdag 17 mei 2018 15:47
Aan: BITX20@groups.io
Onderwerp: Re: [BITX20] Using IRF530 outputs and 2N3553 drivers in ubitx

 

I have used the Minipa 70 in my scratch built BitX. While I can get 70 Watts out (13.8v supply), it is short lived as a final will blow within a few seconds and short closed. 50 Watts will work for short QSOs, but taking for more than four or five seconds will destroy the IRF530s. My heat sink is 6”x4” with 2” fins, so I don’t think heat dissipation is the issue. 25 Watts gives me no issues, however. 

 

Virus-free. www.avg.com

 

Arv Evans
 

Ludo

It is done.

Arv  K7HKL
_._


On Thu, May 17, 2018 at 8:17 AM, ludo schoofs <ludoschoofs@...> wrote:

Hi,

 

Can You remove this email adres: ludoschoofs@...

 

With the transition to from Yahoo to Groups.io I changed an adres. This, the old one,  kept receiving mails.

 

Thanks,

 

Regards

 

Ludo

ON7JW

 

Van: BITX20@groups.io [mailto:BITX20@groups.io] Namens Richie Chambless
Verzonden: donderdag 17 mei 2018 15:47
Aan: BITX20@groups.io
Onderwerp: Re: [BITX20] Using IRF530 outputs and 2N3553 drivers in ubitx

 

I have used the Minipa 70 in my scratch built BitX. While I can get 70 Watts out (13.8v supply), it is short lived as a final will blow within a few seconds and short closed. 50 Watts will work for short QSOs, but taking for more than four or five seconds will destroy the IRF530s. My heat sink is 6”x4” with 2” fins, so I don’t think heat dissipation is the issue. 25 Watts gives me no issues, however. 

 

Virus-free. www.avg.com