David, Thanks for the information. The Elector seems like a poor path for me to follow. I will look into the other group but will continue my quest for a more general coverage SDR. I am using an RXTX6.2 and really enjoy the aspects of SDR.
73, Jack --- In [email protected], "drmail377" <[EMAIL PROTECTED]> wrote: > > Hi Jack, > > You might want to rethink building that Elektor board, at least the > way it is "out of the box". I took a good look at it and found that it > uses a Cypress Semiconductor CY27EE16 PLL Clock Generator as a > synthesized local oscillator. The CY27EE16 has a typical jitter > specification of 250ps rms. This is pretty bad. By comparison, a good > crystal oscillator should present less than 1ps rms jitter. To give > you an idea how this translates to phase noise: > > 0.4psrms jitter (Isotemp OCXO134-10 10MHz VC-OCXO): > 10Hz = -105 dBc/Hz > 100Hz = -125 dBc/Hz > 1000Hz = -140 dBc/Hz > > 230psrms jitter (for comparison): > 10Hz = -50 dBc/Hz > 100Hz = -70 dBc/Hz > 1000Hz = -85 dBc/Hz > > Not only that, I get the feeling that the CY27EE16ZE may be set for > deprecation. At least the Blueberry demo board for the part has been > discontinued and replaced with a Peppermint demo board. The Peppermint > demo board uses a CY22393 three PLL clock synthesizer part. The > CY22393 has even worse specified jitter, a whopping 400psrms! But > there are allusions in the data sheet that the jitter may be > significantly less for some "settings", but it doesn't elaborate. I've > just received a couple of Peppermint boards to test. > > Anyway, the seemingly poor choice of L.O. on the Elektor radio, along > with the outrageously high price put me off. If you do build one of > these, you might want to replace the CY27EE16ZE with an Si570. The > Si570's jitter is specified at around 0.35psrms. Mike, KF4BQ has > measured the phase noise of the CMOS version of Si570 to be - 130dBc/Hz > at 3-7kHz offset. His report is in the Files section. > > If you do replace the CY27EE16ZE with an Si570 (or something else), > remember the G8JCF SDR software that accompanies the Elektor radio > most likely will not be able to control the L.O. frequency. There's a > group here for the G8JCF software with some discussion on the Elektor > board as well - but not a lot of activity: > > http://groups.yahoo.com/group/G8JCFSDR/ > > 73's David (WB4ONA) > > --- In [email protected], "artus1947" <artus@> wrote: > > > > Hi folks, > > > > I wonder if anyone knows of any other sources for the Elector Boards -- > > the shipping to the States (25 euros) is horrible. I tried etching the > > boards myself, but I can't get a good registration between layers. > > Thanks. > > > > 73, > > Jack (W0FNQ) > > >
