Geoff, I do not have proper equipment to do a true noise figure measurement, but my signal generator will go down to -140 dBm, and I can give the number of dB above the receive noise floor for that signal strength - I can do that at various temperatures during the other tests.
I doubt the temperature rise will affect the active devices, but a change in temperature *could* alter the inductors a bit which could detune the input circuits slightly. At this point, that is all speculation. 73, Don W3FPR Geoffrey Mackenzie-Kennedy wrote: > Don, > > I do not like to add to your workload, but I would be interested to know if > the heat generated by the Mitsubishi power module has any negative effect on > the transverter's noise figure (receive mode) if you have the time to > measure it. If I understand the layout of the XV50 correctly, the input > circuitry of its receive path is placed quite close to the power module. > > My reason for asking is that I have been considering the option of buying a > XV50 for use in a set up dedicated only to 6m EME, rather than building a > transverter from scratch > > 73, > Geoff > GM4ESD > > > Don Wilhelm wrote on Sunday, June 06, 2010 at 3:59 AM: > > > > >> Gentleman, >> >> My promised temperature rise measurements will have to be delayed a >> bit. This XV50 has a bad power output module and I will have to wait >> for one to be sent from Watsonville. Later next week, I will have the >> data. >> >> BTW - Mitsubishi in their notes at the end of the data sheet suggest >> that the module case temperature should be limited to 60 deg/C - but >> that is "too hot to touch" (140 deg/F), so the "excessively hot" >> criteria may actually be well within the limits of tolerance - I would >> not want to hold my hand very long on a surface that is at 60 deg/C. >> Also, I do agree that other components can be affected by the >> temperature rise, but most are spec-ed at 60 deg/C, so in reality, there >> may be no problem, just a "discomfort zone" - details after the new >> module arrives. >> >> 73, >> Don W3FPR >> > > > > > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:[email protected] > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > > ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
