I would like a copy of the article please. cheers, Graham ve3gtc planophore@aei.ca On 2014-11-13 00:47, Don Latham wrote: > I digitized the first 2011 article to hand, the one in Jan-Feb; it's a smaller > article, and not as elegant as the later one. Anyone interested can email me > off-list. You're allowed to have a copy for your own use, just can't > re-publish. > Don > > Jim Sanford >> I'm a member, and the article is not there -- just the Excel spreadsheet >> and a Word document of the parts list. >> Too bad, I have a handful of 5 MHzx TCXOs. >> I may have hardcopy of the issue, will have to dig for it. >> >> Jim >> wb4gcs@amsat.org >> >> On 11/12/2014 3:34 PM, Dave M wrote: >>> I am able to download the files associated with the article, but not >>> the article itself. Guess I need to be a paying member to get the >>> article. The only files in the download are the XLS file for >>> calculating the filter values, and the parts list. >>> >>> It's at http://www.arrl.org/qexfiles in the year 2011 listings, >>> filename 3x11_Roos.zip >>> titled "Converting a Vintage 5 MHz Frequency Standard to 10 MHz with a >>> Low Spurious Frequency Doubler" >>> >>> Dave M >>> >>> John C. Roos via time-nuts wrote: >>>> Several list members contacted me expressing interest in the >>>> article. None of them were able to download much or anything >>>> from the ARRL QEX web site. That includes me and other ARRL members. >>>> I am working the issue with one call to ARRL so far today. I will >>>> contact Larry Wolfgang at ARRL and see what Ican bust loose. So >>>> hang in there. It is a cute technique, not originated by me, but >>>> useful. Right now I have to get the ARRL FMT done first. >>>> -73 john c roos k6iql >>>

Is that the "A Two Diode Frequency Doubler" article by John Pivnichny? DaveD On 11/12/2014 10:47 PM, Don Latham wrote: > I digitized the first 2011 article to hand, the one in Jan-Feb; it's a smaller > article, and not as elegant as the later one. Anyone interested can email me > off-list. You're allowed to have a copy for your own use, just can't > re-publish. > Don > > Jim Sanford >> I'm a member, and the article is not there -- just the Excel spreadsheet >> and a Word document of the parts list. >> Too bad, I have a handful of 5 MHzx TCXOs. >> I may have hardcopy of the issue, will have to dig for it. >> >> Jim >> wb4gcs@amsat.org >> >> On 11/12/2014 3:34 PM, Dave M wrote: >>> I am able to download the files associated with the article, but not >>> the article itself. Guess I need to be a paying member to get the >>> article. The only files in the download are the XLS file for >>> calculating the filter values, and the parts list. >>> >>> It's at http://www.arrl.org/qexfiles in the year 2011 listings, >>> filename 3x11_Roos.zip >>> titled "Converting a Vintage 5 MHz Frequency Standard to 10 MHz with a >>> Low Spurious Frequency Doubler" >>> >>> Dave M >>> >>> John C. Roos via time-nuts wrote: >>>> Several list members contacted me expressing interest in the >>>> article. None of them were able to download much or anything >>>> from the ARRL QEX web site. That includes me and other ARRL members. >>>> I am working the issue with one call to ARRL so far today. I will >>>> contact Larry Wolfgang at ARRL and see what Ican bust loose. So >>>> hang in there. It is a cute technique, not originated by me, but >>>> useful. Right now I have to get the ARRL FMT done first. >>>> -73 john c roos k6iql >>> >>> _______________________________________________ >>> time-nuts mailing list -- time-nuts@febo.com >>> To unsubscribe, go to >>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >>> and follow the instructions there. >>> >> >> --- >> This email is free from viruses and malware because avast! Antivirus >> protection is active. >> http://www.avast.com >> >> _______________________________________________ >> time-nuts mailing list -- time-nuts@febo.com >> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >> and follow the instructions there. >> >> >

For those who may be curious, I dug out the schematic for my version of the quadrature-driven DBM frequency doubler and posted it to ko4bb.com. It uses a quadrature hybrid coupler to generate +45 and -45 degree signals at 5MHz, buffers them with emitter followers, and applies them to the RF and LO inputs of a Level 7 DBM. The file name is "Frequency doubler quadrature DBM" (it should be searchable once it is moved out of the recent upload directory). Due to the excellent balance of the quadrature hybrid coupler and the DBM, the spurious products in the mixer output are all odd-order harmonics of 10MHz, the strongest being 30MHz at about -35dBc. The 5MHz feedthrough is about -50dBc. Note that these depend on the mixer balance and circuit layout, as well as the quadrature coupler design and construction. Also shown is an active filter/amplifier that brings the 10MHz output back up near 1Vrms and lowers the 30MHz harmonic to ~ -60dBc and the 5MHz feedthrough to ~ -65dBc. If a simple series LC is used to feed the load, H3 and 5MHz feedthrough can be reduced further to ~ -80dBc. Bandpass filters at the output frequency can create phase modulation with temperature changes. Accordingly, they are presumptively disfavored. However, I built the whole circuit into a smallish cast aluminum box, which integrates any external temperature changes with a long time constant (tens of minutes), and have never had any problem in this regard. For many applications there is no need for any filtering (other than a simple LP noise filter) after the mixer. Because the even-order output products are very well suppressed, the output waveform is nearly perfectly symmetrical. This means that it has a 50% duty cycle and maintains its 50% duty cycle when it is AC coupled or DC-restored, so triggering can always be stable at the center point of the waveform. This inherent freedom from spurious outputs and suppression of even-order output harmonics makes the circuit attractive wherever low spurious output is desired, compared to diode doublers or active push-push circuits. For any required suppression of spurs, the DBM doubler needs less aggressive filtering because of its inherent balance. It also avoids the flicker noise that is characteristic of diode, BJT, and FET doublers. Of course, any design is an exercise in compromise and meeting required performance goals, and there are always many means to reach the end, so different designers will choose different paths. This is one I happen to like. If you try it, you may find that you do, too. Note: The circuit works without the emitter follower buffers, but the spurious outputs are somewhat higher due to the nonlinear loading on the hybrid coupler. This may still be useful if an all-passive circuit is required. Best regards, Charles