Dave I am interested in more information about the usability of the Elektor May 2007 SDR. I have seen somewhere information about too low SNR ratio for hamradio listening and similar weak signals. I need a receiver to use when travelling abroad and sometimes also listening on local radionets in the tropics. They use frequencies around 4 MHz. Would the Elektor May 2007 SDR suit these needs?
Greetings Roland Andersson --- Dave Wade <[EMAIL PROTECTED]> skrev: > As a user of the Elektor project I find its an > excellent product. can you > explain what the effect the phase jitter has on > received signal. For me the > Elektor project provides general coverage receivce > with a similat cost to > mid-range receivers an either reduced size or cost. > Comparing it with a > "Classic" such as an RA17 or a HRO its somewhat > smaller, offers better > sideband suppression , at what I think would be a > similar cost. > > > > If I was going to go for better quality I would be > looking at something that > sampled at RF and so would cost of the order of five > times that of the > elector > > > > Dave > > G4UGM > > > > -----Original Message----- > From: [email protected] > [mailto:[EMAIL PROTECTED] On > Behalf Of artus1947 > Sent: 31 March 2008 01:26 > To: [email protected] > Subject: [soft_radio] Re: Elector Boards > > > > 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] > <mailto:soft_radio%40yahoogroups.com> ups.com, > "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. > <http://groups.yahoo.com/group/G8JCFSDR/> > yahoo.com/group/G8JCFSDR/ > > > > 73's David (WB4ONA) > > > > --- In [EMAIL PROTECTED] > <mailto:soft_radio%40yahoogroups.com> ups.com, > "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) > > > > > > > > > __________________________________________________________ Går det långsamt? Skaffa dig en snabbare bredbandsuppkoppling. Sök och jämför hos Yahoo! Shopping. http://shopping.yahoo.se/c-100015813-bredband.html?partnerId=96914325
