But cooling / heating systems designed to work over a Wide temperature range (ie. Parts of Northern Canada where outside temperatures of perhaps -40C in the winter and +35C in the summer are within the relm of possibility) can be somewhat more expensive / complicated than systems designed for mild climates.
I can sort of see why someone might want electronic equipment that could work at -40C especially if the equipment was going to reside in an unattended shelter that was hard to get to. I realize that in practice this is likely to be difficult (: Mark Spencer m...@alignedsolutions.com 604 762 4099 > On Apr 8, 2020, at 7:09 PM, Bob kb8tq <kb...@n1k.org> wrote: > > Hi > > Running a hard disk at -40 C is pretty much a no-go sort of thing. Even > finding CPU > or FPGA chips rated for operation down there is difficult / expensive. DRAM > chips with > the “right” timing … not so much. Bottom line - the heater / HVAC costs > *way* less than > designing all that stuff to work over a wide temperature range. > > Bob > >> On Apr 8, 2020, at 9:58 PM, Hal Murray <hmur...@megapathdsl.net> wrote: >> >> >> kb...@n1k.org said: >>> Well, based on conversations with the people who designed the part, the >>> outer oven’s only function was to take care of a potential cold end >>> problem. >>> At the time, the telecom guys were thinking of putting GPSDO’s in systems >>> with no heating on the enclosures. That idea died when they ran into a >>> variety of issues with the digital side of things at cold temperatures. >> >> What's the problem with digital gear at cold temperatures? The only one I >> can >> think of is that electrolytic capacitors stop working when the electrolyte >> freezes. >> >> Do signal integrity problems appear when the rise time from CMOS drivers >> gets >> faster? >> >> What sort of warmth did the telecom guys decide they needed? I live in >> California, at sea level rather than up in the mountains. We get occasional >> freezing from radiation cooling on clear nights. They wouldn't have to work >> very hard to keep a box above freezing. I'll have to look closer the next >> time I see some cell phone antennas. >> >> >> -- >> These are my opinions. I hate spam. >> >> >> >> >> _______________________________________________ >> time-nuts mailing list -- time-nuts@lists.febo.com >> To unsubscribe, go to >> http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com >> and follow the instructions there. > > > _______________________________________________ > time-nuts mailing list -- time-nuts@lists.febo.com > To unsubscribe, go to > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > and follow the instructions there. _______________________________________________ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
