Mark Sims wrote:
I have done quite a bit of work replacing fans in old equipment with modern fans.
I have never seen a case where replacing a hurricane level fan with a whisper
quiet fan made any real difference in the cooling inside the unit... typically
one sees less than +/- 5C difference anywhere inside the box. Some places get a bit cooler and some a bit warmer. This is incorrect. ECL components require a minimum airflow velocity that is rather high. The purpose of the large fan is to maintain this velocity. If a smaller fan is used, the ECL components will get hotter, even though the air flowing past them is not much hotter. When you say the fan didn't make any real difference in cooling inside the unit, did you measure the temperature of the ECL DIP's? "Modern" fans obey the same laws of physics as the original equipment. They don't magically produce more airflow for less noise. It would also be a mistake to assume automatically that all HP equipment is overdesigned. I remember one logic analyzer was referred to internally as the "logic furnace", which had a high failure rate. Rick Karlquist N6RK _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.