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Showing posts from March 12, 2017


WD2XSH/17  50 decodes last night   best snr -9  2x     impressive signal No other TA call seen  possible  XSH had extra  high ERP last night 2017-03-12 02:46   WD2XSH/17   0.475639   -9   0   FN42pb   5   PA0O   JO33hg   5630 QTX  now IRFP4227      plastic  en  drain  isolated from cool flange  that isolated drain tricked me  i had +V supplied over the heathsink for the IRF540 but that did not work with this IRFP i needed to power it over pin2 although  the document shows that cool flange and pin 2 are both drain But if could not get it to work stable, the some sort of wild oscillations  that killed the IRF540 appear sometimes found that the oscillation was caused by the 475 band filter and puls shaper it is stable now it stays cool only the air coils heath up Ths IRFP  is more like a tube it can survive bad treatment more..


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