On 20/01/17 18:01, [email protected] wrote: > From: Wayne Burdick <[email protected]> > To: Guy Olinger K2AV <[email protected]> > Cc: Doug Smith <[email protected]>, Elecraft Reflector > <[email protected]> > Subject: Re: [Elecraft] K3: past chirp report > Message-ID: <[email protected]> > Content-Type: text/plain; charset=windows-1252 > > This is not a factor in synthesizer switching. Both the old and new synths > incorporate their own voltage regulators, preserve identical signal integrity > down to a power supply voltage of around 9 VDC. That's about as low as the > radio can go in any case. > > Wayne > N6KR
Does the radio still chirp when run on a large linear PSU, or from a very well charged battery. (In a vehicle with the engine running for example.) Unless specifically designed for such use, Switching PSU's are generally quite poor in regards to dynamic regulation (such as would be needed for QRO CW or SSB.) However, from what Wayne describes above, even if the incoming DC dips a little, I get the impression the DC rail for the synthesizer itself is likely to stay clean. But, while the SMPS is recovering from a sudden large load being applied, it could introduce a burst of noise on the PS lines, that might couple into other things causing trouble. Similar things also happen when the load (RF) is suddenly turned off, then though, you get a voltage spike, and maybe some "cycle skipping" in the PSU as it tries to prevent such... What make/model of PSU? I've yet to find one for the "Amateur" market that is anyway near half as good as the mega bucks SMPS cinder block sized things we use in the commercial multi kW QRO amps we handle at work. And even they have a few issues when the amp is carrying high levels of pulsed RF. And the types designed for telecom or "server" use, are often very much poorer in regards to dynamic regulation, especially if the RX current draw is a under 10 to 15% of their rated max load, as they would have been designed for a high power delivery, that does not vary much. 73. Dave G0WBX. ______________________________________________________________ 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 Message delivered to [email protected]
