The new synth uses a hybrid DDS-PLL architecture running at a very high frequency. Many newer transceivers use a DDS only. The PLL is critical to low-noise (low-jitter) performance.
The DDS-PLL subsystem is locked to the 49.380-MHz reference to within a small fraction of a Hz over the entire tuning range. 73, Wayne N6KR On Mar 10, 2015, at 1:54 PM, Giuliano Carmignani <[email protected]> wrote: > A simple question : > the new synthesizer uses a DDS? If yes what is the type? > 73 > Giuliano I0CG > Italy > K1,K2,K3+P3 > > >> Message: 18 >> Date: Tue, 10 Mar 2015 15:54:24 -0000 >> From: "Dave Olean"<[email protected]> >> To: "Elecraft Reflector"<[email protected]> >> Subject: [Elecraft] A datapoint comparing old vs new synthesizer >> boards. >> Message-ID: <3AE5C8AA7D6B4DF2A2932520B75DCF21@t30ce0d73e1b34> >> Content-Type: text/plain; charset="iso-8859-1" >> >> I recently got a new K3 and it was one of the first units supplied with the >> new and improved synthesizer board. In reading a few comments on the >> reflector, a number of people wanted to know if anyone could detect any >> difference between the old and the new. I also have some older K3s and >> decided to compare one of them head to head with the new one on ten meter CW >> using a 500 Hz bandwidth and check for MDS. I used the line out jack and an >> HP AC VTVM and 8640B signal generator. Here is what I found: >> K3 #8858 no preamp -137 dBm new synthesizer board >> preamp ON -139 dBm new synthesizer board >> K3 #1504 no preamp -134.5 dBm old synthesizer board >> preamp ON -137 dBm old synthesizer board >> >> I also ordered a pair of synth boards for one of my old K3s on March 1, but >> it will be awhile before it gets here I guess. I ordered a P3 kit with it >> and included comments that I was in no rush for the P3 so ship it all >> together. From the comments I have seen on how many have been ordered, I >> might be waiting a long time for the P3!! At my age, I'll probably forget >> about the order in another week or so. When it shows up, I'll wonder what it >> is and who ordered it!! The plan is to put new synth boards into #1504 and >> then I can check MDS again to see how it looks. From my checking, it looks >> like the newer K3 is almost 3 dB better than the older one at least as far >> as minimum discernable signals go. The new board definitely makes a >> difference, and my result tracks reasonably well with what what others have >> found. >> >> Dave K1WHS > > ______________________________________________________________ > 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] ______________________________________________________________ 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]
