Return-Path: Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by mtain-mg06.r1000.mx.aol.com (Internet Inbound) with ESMTP id 16393380000F5; Mon, 20 Feb 2012 17:20:33 -0500 (EST) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1Rzba8-00021h-Hx for rs_out_1@blacksheep.org; Mon, 20 Feb 2012 22:19:40 +0000 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1Rzba7-00021Y-WC for rsgb_lf_group@blacksheep.org; Mon, 20 Feb 2012 22:19:39 +0000 Received: from mail-iy0-f171.google.com ([209.85.210.171]) by relay1.thorcom.net with esmtp (Exim 4.63) (envelope-from ) id 1Rzba4-0004Zb-M8 for rsgb_lf_group@blacksheep.org; Mon, 20 Feb 2012 22:19:39 +0000 Received: by iaeh11 with SMTP id h11so13814071iae.16 for ; Mon, 20 Feb 2012 14:19:30 -0800 (PST) Received-SPF: pass (google.com: domain of andy.g4jnt@gmail.com designates 10.50.208.74 as permitted sender) client-ip=10.50.208.74; Authentication-Results: mr.google.com; spf=pass (google.com: domain of andy.g4jnt@gmail.com designates 10.50.208.74 as permitted sender) smtp.mail=andy.g4jnt@gmail.com; dkim=pass header.i=andy.g4jnt@gmail.com Received: from mr.google.com ([10.50.208.74]) by 10.50.208.74 with SMTP id mc10mr9607556igc.28.1329776370058 (num_hops = 1); Mon, 20 Feb 2012 14:19:30 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :content-type; bh=a8AVq6wzJ/x/+rNgknz1El8HAccGGwvsLso2HXeRscY=; b=JRPOkNXP14uO6jLp6ouMk0Xm6k2dXMVV1FijkPqURxWVESTQHI7VHxyL07NPhDf/rp 24iJCZPVdSaTngjJGC2WIl6/AnJTkDV3qCmeK6SzOC6cMCkASqCYCAo77IjPVKfsjacB oEdCMEiaPlt1xUXU2OJenvvE6JWWg3FlpNTqo= MIME-Version: 1.0 Received: by 10.50.208.74 with SMTP id mc10mr7801668igc.28.1329776369595; Mon, 20 Feb 2012 14:19:29 -0800 (PST) Received: by 10.231.158.68 with HTTP; Mon, 20 Feb 2012 14:19:29 -0800 (PST) In-Reply-To: References: Date: Mon, 20 Feb 2012 22:19:29 +0000 Message-ID: From: Andy Talbot To: rsgb_lf_group@blacksheep.org X-Spam-Score: 0.0 (/) X-Spam-Report: autolearn=disabled,HTML_MESSAGE=0.001 Subject: Re: LF: Measurements on 10MHz references Content-Type: multipart/alternative; boundary=14dae9340c9f23f31e04b96cb006 X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: X-Spam-Status: No, hits=0.5 required=5.0 tests=HTML_20_30,HTML_MESSAGE autolearn=no version=2.63 X-SA-Exim-Scanned: Yes Sender: owner-rsgb_lf_group@blacksheep.org Precedence: bulk Reply-To: rsgb_lf_group@blacksheep.org X-Listname: rsgb_lf_group X-SA-Exim-Rcpt-To: rs_out_1@blacksheep.org X-SA-Exim-Scanned: No; SAEximRunCond expanded to false x-aol-global-disposition: G X-AOL-SCOLL-SCORE: 0:2:415018656:93952408 X-AOL-SCOLL-URL_COUNT: 0 X-AOL-SCOLL-AUTHENTICATION: mail_rly_antispam_dkim-m215.1 ; domain : gmail.com DKIM : pass x-aol-sid: 3039ac1d60ce4f42c730738a X-AOL-IP: 195.171.43.25 X-AOL-SPF: domain : blacksheep.org SPF : none --14dae9340c9f23f31e04b96cb006 Content-Type: text/plain; charset=ISO-8859-1 Yes, of course. Take 5MHz input at around +10dBm, use a bi or trifilar transformer to give 0/180 deg equal amplitude ouptuts, pair of shotky diodes in classic full wave, choke to ground to complete the DC path. Output at 2X with about 10dB loss. ~ 40dB of fundamental rejection if the input transformer is wound properly There are other even order harmonics present too, but who cares about them. They are just harmonics of the wanted signal. Andy www.g4jnt.com On 20 February 2012 20:08, Graham wrote: > ** > >>generate 5MHz which was doubled for these measurements using a > full-wave rectifier doubler.<< > > Can you do that ? > > *From:* Andy Talbot > *Sent:* Monday, February 20, 2012 7:00 PM > *To:* ukmicrowaves@yahoogroups.com ; rsgb_lf_group@blacksheep.org ; > uk_beacons@yahoogroups.com > *Subject:* LF: Measurements on 10MHz references > > In the file http://www.g4jnt.com/DownLoad/10MHz_ReferenceSpurii.pdf > are plots of the 10MHz outputs from several 10MHz references and > oscillators. > They include four GPSDOs of varying types, an HP5061 Caesium standard, an > oldish high quality TCXO recovered from a 1980's vintage STL comms > receiver, and my long in the tooth MSF frequency reference using a Toyocom > OCXO. > This latter, and the Cs standard, both generate 5MHz which was doubled for > these measurements using a full-wave rectifier doubler. > > All plots were made using an SDR-IQ on the same settings: 0.37Hz FFT bin > at spans of 10kHz and 100kHz with 4 times averaging. The final two > measurements on the two Simple GPSDOs were made by G0API using his SDR-IQ > with the same setup as mine. For all plots, signal level / attenuation > were adjusted to be as close to full scale as possible without overload. > > Some artefacts at the -100dBc to -110dBc region seem to be in common > across several plots, and I suspect these are locally generated or due to > the SDR-IQ. However, there are enough and sufficient differences to see > that some sources are definltely better than others, and that the cheaper > cost conditioners do allow spurious signals onto the output. > > My own ZAZ GPSDO, the second set of plots, originally showed unstable > sidebands at 650Hz which I realised were coming from an LCD backlight > inverter. With this removed, it is now shown to be one of the better > sources - but with the high spec TCXO that was recovered from the old Decca > Navigator chain, berhaps not too surprising. > > Teh second ZAZ plot, using the modern Morion OCXO is the cleanest in terms > of spuriou, although the phase noise of that oscillator is higher than many > of the others. This is, I believe, characteristic of that OCXO which was > used originally mainly as a a timing unit, specifically for its fast warm > up and low retrace errors rather than for its noise performance. > > > Andy > www.g4jnt.com > > --14dae9340c9f23f31e04b96cb006 Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable
Yes, of course.
Take 5MHz input at around +10dBm, use a bi or trifilar transformer to = give 0/180 deg equal amplitude ouptuts, pair of shotky =A0diodes in classic= full wave, choke to ground to complete the DC path.=A0=A0 Output at 2X wit= h about 10dB loss.=A0=A0=A0~ 40dB of fundamental rejection if the input tra= nsformer is wound properly
=A0
There are other even order harmonics present too, but who cares about = them. They are just harmonics of the wanted signal.
=A0
Andy


=A0
On 20 February 2012 20:08, Graham <g8fzk@g8fzk.fsnet.co.uk<= /a>> wrote:
>>generate 5MHz which was doubled for these measurements using a= full-wave rectifier doubler.<<
=A0
Can you=A0 do=A0 that=A0 ?

Sent: Monday, February 20, 2012 7:00 PM
Subject: LF: Measurements on 10MHz references

In the file=A0=A0=A0 http://www.g4jnt.com/DownLoad/10MHz_Re= ferenceSpurii.pdf=A0=A0=A0 are plots of the 10MHz outputs from several = 10MHz references and oscillators.=A0=A0
They include=A0four GPSDOs of varying types, an HP5061 Caesium standar= d, an oldish high quality TCXO recovered from a 1980's vintage STL comm= s receiver, and my long in the tooth MSF frequency reference using a Toyoco= m OCXO.=A0
This latter,=A0and the Cs standard, both generate 5MHz which was doubled fo= r these measurements using a full-wave rectifier doubler.
=A0
All plots were made using an SDR-IQ on the same settings: 0.37Hz FFT b= in at spans of 10kHz and 100kHz with 4 times averaging.=A0 The final two me= asurements on the two Simple GPSDOs were made by G0API using his SDR-IQ wit= h the same setup as mine.=A0=A0 For all plots, signal level / attenuation w= ere adjusted to be as close to full scale as possible without overload.
=A0
Some artefacts at the -100dBc to -110dBc region seem to be in common a= cross several plots, and I suspect these are locally generated or due to th= e SDR-IQ.=A0=A0 However, there are enough and sufficient differences to see= that some sources are definltely better than others, and that the cheaper = cost conditioners do allow spurious signals onto the output.
=A0
My own ZAZ GPSDO, the second set of plots, originally showed unstable = sidebands at 650Hz=A0which I realised were coming from an LCD backlight inv= erter.=A0 With this removed, it is now shown to be one of the better source= s - but with the high spec TCXO that was recovered from the old Decca Navig= ator chain, berhaps not too surprising.=A0=A0
=A0
Teh second ZAZ plot, using the modern Morion OCXO is the cleanest in t= erms of spuriou, although the phase noise of that oscillator is higher than= many of the others.=A0=A0 This is, I believe, characteristic of that OCXO = which was used originally mainly as a a timing unit, specifically =A0for it= s fast warm up and low retrace errors rather than for its noise performance= .
=A0
=A0
Andy
www.g4jnt.com<= /div>
=A0

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