Very true indeed. The price for a decent regulated dc supply has dropped for the past years.
Sent from my iPhone 4 Don Wilhelm <[email protected]> 於 2011年5月11日 上午11:44 寫道： > David, > > I have many times commented negatively on the use of unregulated wall > warts for use with any radio because the no load (low load) voltage can > be substantially greater than the rated voltage (the specified voltage > is only at full load). Many 12 volt wall warts will develop 17 volts or > more at no load. Those power supplies intended for laptop computers may > do the job, but still, I shudder at using them unmodified, and that does > not speak to any potential spurious responses (some call them "birdies") > coming from the power supply. > > Regulated wall warts are a different matter (birdies not considered) - > if they will provide the required current at 13.8 volts or so, then > there is no harm in using them, but the availability of 13.8 volt > regulated wall-warts is close to zero at the sources I normally use - it > seems all the available ones with sufficient current that I have located > are unregulated. > > Use wall-warts and computer power supplies at your own peril. For me, I > would not subject any radio to such a power source. With the K3 in > particular, if one has spent upwards of $1.5k for the radio, then why > "go cheap" on the power source. Spend a few extra dollars and obtain a > good 13.8 volt power supply - you will be more satisfied in the long run. > > 73, > Don W3FPR > > On 5/10/2011 9:04 PM, David Gilbert wrote: >> Didn't someone here not too long ago post some information on the >> unreliable voltage regulation of many wallwart/laptop supplies? Maybe >> it wasn't this reflector. In general, though, I believe the thread >> mentioned that many of those supplies assume a load, and under no load >> conditions the voltage often went up several volts. The K3 has it's own >> internal voltage regulators, but I'm not sure I'd want to subject them >> to that sort of over voltage at turn on. >> >> Dave AB7E >> > ______________________________________________________________ > 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
