<div>Hi All,</div> <div>ECL is pretty easy to use. All you need to do is treat it like an RF device. Then just follow the loading and transmission rules. When AC logic came out I saw all the old ECL rules surface. </div> <div>I wonder why nobody has thought of using FETs as switches? The first H mode used an SD5000. Why not look at discrete parts. I have found stuffing too much stuff on one substrate can cause cross talk. I was actually surprised with the performance of the FST3253 at HF. This may take a second transformer but if it was rated for 50 or so watts it should work. </div> <div>I have a hard time trusting the HP8640B for dynamic ranges over 100 dB. I get the feeling theer is interaction between generators. A friend who has been doing high dynamic range stuff uses a pair of isolation amplifiers after the generators to avoid problems.</div> <div>lurker frank wa1gfz. </div> <div><BR><BR><B><I>hpsdr-request@hpsdr.org</I></B> wrote:</div> <BLOCKQUOTE
class=replbq style="PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: #1010ff 2px solid">Send hpsdr mailing list submissions to<BR>hpsdr@hpsdr.org<BR><BR>To subscribe or unsubscribe via the World Wide Web, visit<BR>http://lists.hpsdr.org/listinfo.cgi/hpsdr-hpsdr.org<BR>or, via email, send a message with subject or body 'help' to<BR>hpsdr-request@hpsdr.org<BR><BR>You can reach the person managing the list at<BR>hpsdr-owner@hpsdr.org<BR><BR>When replying, please edit your Subject line so it is more specific<BR>than "Re: Contents of hpsdr digest..."<BR><BR><BR>PLEASE change your subject line in any replies to this digest to reflect the actual subject!!! We all thank you for this thoughtfullness.<BR><BR>Today's Topics:<BR><BR>1. Re: An high dynamic QSD front-end (Giancarlo Moda)<BR>2. Re: Phoenix (Ray Anderson)<BR>3. Re: An high dynamic QSD front-end (Marco IK1ODO)<BR>4. Re: An high dynamic QSD front-end (Marco IK1ODO)<BR>5. Re: An high dynamic QSD front-end (Lyle
Johnson)<BR>6. Re: An high dynamic QSD front-end (Robert McGwier)<BR>7. ADG901 (Geoff)<BR>8. Re: ADG901 (Dan Andersson)<BR>9. Re: ADG901 (Ahti Aintila)<BR><BR><BR>----------------------------------------------------------------------<BR><BR>Message: 1<BR>Date: Mon, 15 Jan 2007 11:01:05 -0800 (PST)<BR>From: Giancarlo Moda <I7SWX@YAHOO.COM><BR>Subject: Re: [hpsdr] An high dynamic QSD front-end<BR>To: HPSDR Group <HPSDR@HPSDR.ORG><BR>Message-ID: <20070115190105.86682.qmail@web37203.mail.mud.yahoo.com><BR>Content-Type: text/plain; charset=iso-8859-1<BR><BR>Hi Bob,<BR><BR>Marco, IK1ODO, has done a very interesting and<BR>welcomed analysis of QSD in SDR. Also Ahti, OH2RZ, has<BR>defined an interesting way to improve QSD.<BR><BR>I would like to report a few comments to your notes<BR>below.<BR>I believe discussions are very important as are way to<BR>exchange ideas and improve designs in the ham or<BR>business field.<BR><BR>Date: Sun, 14 Jan 2007 17:37:06 -0500<BR>From:
Robert McGwier <RWMCGWIER@GMAIL.COM><BR>Subject: Re: [hpsdr] An high dynamic QSD front-end<BR>To: Ahti Aintila <OH2RZ.SDR@GMAIL.COM><BR>Cc: Marco IK1ODO <IK1ODO@SPIN-IT.COM>, hpsdr@hpsdr.org<BR>Message-ID: <45AAB092.8020300@gmail.com><BR>Content-Type: text/plain; charset=ISO-8859-1;<BR>format=flowed<BR><BR>Congratulations. Very nice analysis, very<BR>straightforward, not <BR>requiring the machinery of Laplace transforms to<BR>understand the reasons <BR>which the "intuition impoverished mathematician" had<BR>to do to gain <BR>intuition. If you study Leif ?sbrink's WSE hardware<BR>you will see the <BR>great lengths he went to do his "transient fix". He<BR>was working very <BR>hard to supply the current from a suboptimal current<BR>source to overcome <BR>the transients problems with the four phase capacitor<BR><BR>pseudo-integrator. He had a heuristic understanding<BR>of the need some <BR>time ago but did not go fully virtual ground, current<BR>mode with the
<BR>necessary integrator to solve this in the utterly<BR>simple ISD Ahti has <BR>shown us.<BR><BR>Thank you both for a serious elevation of this<BR>discussion. It really <BR>is <BR>time to build hardware. WARNING: We definitely want<BR>to steer away <BR>from <BR>the FST switches. FROM MEASUREMENT, coupled with DDS<BR>issues, they <BR>are <BR>the source of the increasing noise figure. Marco's<BR>plots, as well as <BR>Phil C's and my measurements of various QSD's using<BR>them show this <BR>inescapable fact. <BR><BR>> It was my understanding that Marco did try to<BR>demonstrate the opposite about QSD noise<BR><BR><BR>I think various pieces of analysis have incorrectly <BR>attributed the measurements but the switches are a<BR>major contributor. <BR><BR>> SDR is an interesting field in radiocommunication<BR>but I feel there is still a lot of work to be done as<BR>we do have to learn on how to do measurements with<BR>this kind of receivers contrary to the analog
radio<BR>equipment ...<BR><BR><BR>They solved an early problem and we can thank Gerald<BR>for finding this <BR>part and his very gracious publication in QEX and with<BR>the SDR-1000. <BR><BR>> I would like to underline that I am the ONE that had<BR>the idea, early 1998, to use the Fast Bus Switches<BR>like the FST3125 in mixers to replace diodes and MOS<BR>in particular for the G3SBI H-Mode Mixer. The Idea of<BR>FST use did improve the Tayloe QSD.<BR><BR>But it is time to leave them behind FOREVER.<BR><BR>> Sorry but I do not understand your "FOREVER" in the<BR>abouve phrase. Leave the Forever for all radio project<BR>or FOREVER for SDR ?<BR><BR>I believe we should never close any door to the past<BR>or to the future. I am sure the HPSDR group will<BR>rlease SDR project very advanced going totally with<BR>digital solution ... but we should never forget we are<BR>Amateur Radio and not Business, although there are<BR>many involved in SDR that are also in the
industry.<BR><BR>> There are other colleges experimented with recent<BR>switches like the FSA322 ... that may give H-Mode<BR>Mixer with IP3 around +50dBm .... what will be the<BR>value of IP3 in HPSDR?<BR><BR>Thanks and best 73<BR><BR>Gian<BR>I7SWX<BR><BR>73's<BR>Bob<BR>N4HY<BR><BR><BR><BR><BR>____________________________________________________________________________________<BR>Finding fabulous fares is fun. <BR>Let Yahoo! FareChase search your favorite travel sites to find flight and hotel bargains.<BR>http://farechase.yahoo.com/promo-generic-14795097<BR><BR><BR>------------------------------<BR><BR>Message: 2<BR>Date: Mon, 15 Jan 2007 11:58:07 -0800<BR>From: "Ray Anderson" <RAY.ANDERSON@XILINX.COM><BR>Subject: Re: [hpsdr] Phoenix<BR>To: <HPSDR@HPSDR.ORG><BR>Message-ID:<BR><BD06837F0655E84288539771399A41FF01DB54C8@XSJ-EXCHVS1.XLNX.XILINX.COM><BR>Content-Type: text/plain; charset="us-ascii"<BR><BR>I posted my reply to Lyle's inquiry back around the 1st of the year
when<BR>the mail reflector was acting up. So far I haven't heard from anyone<BR>regarding their desire to become involved in or take over the Phoenix<BR>project. As I mentioned, due to other commitments my time available for<BR>involvement with Phoenix is quite limited as well as my temporary lack<BR>of radio lab facilities.<BR><BR>-Ray WB6TPU<BR><BR>>I'm curious as to the status of Phoenix. Has the QSD op-amp been <BR>>chosen? The DDS or other synthesizer? Is a preamp going to be<BR>required <BR>>in any event to minimize oscillator radiation back to the antenna?<BR><BR>>Thanks!<BR><BR>>Lyle KK7P<BR><BR><BR>Lyle-<BR><BR>Phoenix progress has kind of stalled on my end due to unanticipated<BR>drains on my time both at work and in the evenings.<BR><BR>I have been monitoring the list on a daily basis to keep up to speed on<BR>other HPSDR activity (with particular interest in the QSD discussion<BR>related to the Odyssey project).<BR><BR>In addition to a general
shortage of time I am also temporarily devoid<BR>of debug/troubleshooting facilities to bring a new design to life.<BR>Hopefully that will resolve itself in the not too distant future.<BR><BR>After quite a bit of contemplation I think that an invitation for<BR>assistance from others who have more immediate time and facilities is in<BR>order so as to not unduly delay the realization of Phoenix now that<BR>Janus and Ozy are on the verge of becoming releasable designs. I've been<BR>delaying the plea for extra involvement in the hope I'd have a large<BR>block of time open up, but for the foreseeable future this is looking<BR>kind of doubtful.<BR><BR>If anyone feels like becoming involved in the development of the Phoenix<BR>board (integrated HF RX and TX) in either actual board design and or<BR>bringup/testing/characterization I'd be more than pleased to have them<BR>become associated with the project. I really dislike having the project<BR>unduly delayed due to my current
lack of time and facilities.<BR><BR>Best Regards & 73,<BR><BR>Ray WB6TPU<BR><BR><BR>________________________________<BR><BR>size=2 width="100%" align=center> <BR>-------------- next part --------------<BR>An HTML attachment was scrubbed...<BR>URL: http://lists.hpsdr.org/pipermail/hpsdr-hpsdr.org/attachments/20070115/90d83d35/attachment.html <BR><BR>------------------------------<BR><BR>Message: 3<BR>Date: Mon, 15 Jan 2007 22:28:58 +0100<BR>From: Marco IK1ODO <IK1ODO@SPIN-IT.COM><BR>Subject: Re: [hpsdr] An high dynamic QSD front-end<BR>To: hpsdr@hpsdr.org<BR>Message-ID: <FBCMCL01B01I5GJAKZX000E8EF8@FBCMCL01B01.FBC.LOCAL><BR>Content-Type: text/plain; charset="us-ascii"<BR><BR>At 23.37 14/01/2007, N4HY wrote:<BR>>It really is time to build hardware.<BR><BR>So I did, spending three months to optimize it.<BR><BR>>WARNING: We definitely want to steer away from the FST <BR>>switches. FROM MEASUREMENT, coupled with DDS issues, they are the <BR>>source of the
increasing noise figure. Marco's plots, as well as <BR>>Phil C's and my measurements of various QSD's using them show this <BR>>inescapable fact. I think various pieces of analysis have <BR>>incorrectly attributed the measurements but the switches are a major <BR>>contributor.<BR>>They solved an early problem and we can thank Gerald for finding <BR>>this part and his very gracious publication in QEX and with the SDR-1000.<BR>>But it is time to leave them behind FOREVER.<BR>><BR>>73's<BR>>Bob<BR>>N4HY<BR><BR>Bob,<BR><BR>why do you say so? I think I measured and demonstrated exactly the <BR>opposite: the switching noise from the FST may be minimized, and the <BR>overall level plan of the receiver has to be considered to reduce the <BR>noise contribution of the opamps. I see no "inexcapable facts".<BR>Please consider the figures that I measured - in some point perhaps <BR>by defect, see http://www.spin-it.com/sdr/IK1ODO_SDR1.html<BR><BR>Low
gain audio interface setting (+4dBu f.s.)<BR><BR>RF input level for A/D converter saturation: -3dBm<BR>SFDR: 90dB with -10dBm RF input<BR>Noise floor: -123dBm / 2.4kHz<BR>3' order dynamic range: 105 dB<BR>IIP3: +36dBm<BR><BR><BR>High gain audio interface setting (-10dBu f.s.)<BR><BR>RF input level for A/D converter saturation: -17dBm<BR>SFDR: 100dB with -20dBm RF input<BR>Noise floor: -128dBm / 2.4kHz<BR>3' order dynamic range: 102 dB<BR>IIP3: +25dBm<BR><BR>How many receivers designs get similar figures with such a simple hardware?<BR><BR>I think it's time to go ahead with Phoenix. It will not be the <BR>definitive receiver, but using the ideas of Ahti and my tested <BR>frontend we may get a very nice intermediate solution, at a low cost. <BR>The LO may be derived from I0CG design (AD9951 plus a 500MHz clock); <BR>possibly a PLL in 10kHz (or wider) steps may be better, but it's not <BR>trivial to design it with sufficient spectral purity.<BR><BR>73 - Marco
IK1ODO<BR>-------------- next part --------------<BR>An HTML attachment was scrubbed...<BR>URL: http://lists.hpsdr.org/pipermail/hpsdr-hpsdr.org/attachments/20070115/0912d418/attachment-0001.html <BR><BR>------------------------------<BR><BR>Message: 4<BR>Date: Mon, 15 Jan 2007 22:42:14 +0100<BR>From: Marco IK1ODO <IK1ODO@SPIN-IT.COM><BR>Subject: Re: [hpsdr] An high dynamic QSD front-end<BR>To: Jim Miller <JIM@JTMILLER.COM>, hpsdr@hpsdr.org<BR>Message-ID: <FBCMCL01B05BJJJJGW9000DE268@FBCMCL01B05.FBC.LOCAL><BR>Content-Type: text/plain; charset="us-ascii"; format=flowed<BR><BR>At 23.53 14/01/2007, Jim Miller wrote:<BR><BR><BR>>i'm still left puzzled how any of the active integrators deal with all of<BR>>the signals outside their gain bandwidth capability.<BR>><BR>>they only present a virtual ground to frequencies at which they have<BR>>significant excess gain.<BR>><BR>>what am i missing?<BR>><BR>>73<BR>><BR>>jim ab3cv<BR><BR>Nothing,
Jim.<BR><BR>Please have a look at my schematic at <BR>http://www.spin-it.com/sdr/IK1ODO_SDR1.html<BR><BR>The impedance seen from the RF port is always close to 50 Ohm, at any <BR>frequency.<BR>The key is the diplexer after the integrator. Signal offset more than <BR>250kHz from F0 are grounded there. The opamp is not working at all on <BR>HF signals.<BR>I measured the "blocking" dynamic range, defined as the signal level <BR>that causes A/D saturation or significant distortion in the mixer. <BR>For in-band signals it is -3dBm (for 4Vrms audio out to the EMU); at <BR>1MHz from the tuning frequency +10dBm are needed, then the protection <BR>diodes in the FST start conducting...<BR><BR>The opamp must not see signals outside it's bandwidth. I think I <BR>demonstrated it. Transients out of the QSD reach hundreds of mV with <BR>spectral components in the GHz range; nothing that an audio opamp <BR>could withstand. Blocking them in the diplexer stabilizes the mixer <BR>output
impedance and avoids distortion in the opamp.<BR><BR>73 - Marco IK1ODO<BR><BR><BR><BR>------------------------------<BR><BR>Message: 5<BR>Date: Mon, 15 Jan 2007 13:46:32 -0800<BR>From: Lyle Johnson <KK7P@WAVECABLE.COM><BR>Subject: Re: [hpsdr] An high dynamic QSD front-end<BR>To: Marco IK1ODO <IK1ODO@SPIN-IT.COM><BR>Cc: hpsdr@hpsdr.org<BR>Message-ID: <45ABF638.3060204@wavecable.com><BR>Content-Type: text/plain; charset=ISO-8859-1; format=flowed<BR><BR>> I think it's time to go ahead with Phoenix.<BR><BR>Here is an heretical thought: what if we used the QSD at a fixed IF <BR>frequency and thus didn't need a quadrature, wideband injection source? <BR>That might make a PLL - or even a DDS - solution practical or easier.<BR><BR>If the revised QSD works well above 30MHz, we can use a high IF to ease <BR>image rejection and we wouldn't need much in the way of an IF filter, so <BR>we can still use the QSD to get the 200 kHz or so of spectrum display we <BR>have come to
expect from this sort of design.<BR><BR>We need something in front of the QSD to suppress LO radiation, and the <BR>"front end" filters and whatnot are going to be required as well. An <BR>H-mode mixer will preserve the dynamic range characteristics we want.<BR><BR>73,<BR><BR>Lyle KK7P<BR><BR><BR><BR><BR><BR><BR>------------------------------<BR><BR>Message: 6<BR>Date: Mon, 15 Jan 2007 17:27:54 -0500<BR>From: Robert McGwier <RWMCGWIER@GMAIL.COM><BR>Subject: Re: [hpsdr] An high dynamic QSD front-end<BR>To: Giancarlo Moda <I7SWX@YAHOO.COM><BR>Cc: HPSDR Group <HPSDR@HPSDR.ORG><BR>Message-ID: <45ABFFEA.9070804@gmail.com><BR>Content-Type: text/plain; charset=ISO-8859-1; format=flowed<BR><BR><BR>Hello Gian:<BR><BR>Thank you for your many contributions in the mixer area, to the N2PK VNA <BR>group (both of mine use your circuit boards), and more. Here is what I <BR>know from my own experience, measurements done by Phil Covington, Phil <BR>Harman, and others. From several
QSD's I have measured and have seen <BR>measured the rise in noise figure from (say) 14 to 54 MHz. I see that <BR>Marco has done the same with his very nice work. In each case, the <BR>results are similar, if not identical to those I have measured or others <BR>have measured. In those cases where I have seen these kinds of mixers <BR>done without the FST switches, but with different parts, there is <<NO <br>such rise in noise figure>>. Marco's work has one thing different from <BR>all of the other ISD implementations I have seen. It uses the FST <BR>switches you discovered for us. ;-). Marco's circuit has the rise in <BR>NF which is NOT present in those ISD's I have seen measured which do NOT <BR>have the FST's. I am certain Marco is not sloppy and his work is <BR>excellent and I am taking his graphs as the absolute truth. The logical <BR>implication from this is immediate. The FST switches are the cause of <BR>the rise. I would like to minimize the amount of gain
needed to make <BR>the receiver usable at 10 and 6 meters.<BR><BR>I acknowledge your work and that of Marco. I am giving my opinions on <BR>the best way to proceed, fully aware of all of this work. I read this <BR>group every day and am grateful for all of the wonderful contributions <BR>and sharing.<BR><BR>73's<BR>Bob<BR><BR><BR><BR><BR>Giancarlo Moda wrote:<BR>> ***** High Performance Software Defined Radio Discussion List *****<BR>><BR>> Hi Bob,<BR>><BR>> Marco, IK1ODO, has done a very interesting and<BR>> welcomed analysis of QSD in SDR. Also Ahti, OH2RZ, has<BR>> defined an interesting way to improve QSD.<BR>><BR>> I would like to report a few comments to your notes<BR>> below.<BR>> I believe discussions are very important as are way to<BR>> exchange ideas and improve designs in the ham or<BR>> business field.<BR>><BR>> Date: Sun, 14 Jan 2007 17:37:06 -0500<BR>> From: Robert McGwier <RWMCGWIER@GMAIL.COM><BR>> Subject:
Re: [hpsdr] An high dynamic QSD front-end<BR>> To: Ahti Aintila <OH2RZ.SDR@GMAIL.COM><BR>> Cc: Marco IK1ODO <IK1ODO@SPIN-IT.COM>, hpsdr@hpsdr.org<BR>> Message-ID: <45AAB092.8020300@gmail.com><BR>> Content-Type: text/plain; charset=ISO-8859-1;<BR>> format=flowed<BR>><BR>> Congratulations. Very nice analysis, very<BR>> straightforward, not <BR>> requiring the machinery of Laplace transforms to<BR>> understand the reasons <BR>> which the "intuition impoverished mathematician" had<BR>> to do to gain <BR>> intuition. If you study Leif ?sbrink's WSE hardware<BR>> you will see the <BR>> great lengths he went to do his "transient fix". He<BR>> was working very <BR>> hard to supply the current from a suboptimal current<BR>> source to overcome <BR>> the transients problems with the four phase capacitor<BR>><BR>> pseudo-integrator. He had a heuristic understanding<BR>> of the need some <BR>> time ago but did
not go fully virtual ground, current<BR>> mode with the <BR>> necessary integrator to solve this in the utterly<BR>> simple ISD Ahti has <BR>> shown us.<BR>><BR>> Thank you both for a serious elevation of this<BR>> discussion. It really <BR>> is <BR>> time to build hardware. WARNING: We definitely want<BR>> to steer away <BR>> from <BR>> the FST switches. FROM MEASUREMENT, coupled with DDS<BR>> issues, they <BR>> are <BR>> the source of the increasing noise figure. Marco's<BR>> plots, as well as <BR>> Phil C's and my measurements of various QSD's using<BR>> them show this <BR>> inescapable fact. <BR>><BR>> <BR>>> It was my understanding that Marco did try to<BR>>> <BR>> demonstrate the opposite about QSD noise<BR>><BR>><BR>> I think various pieces of analysis have incorrectly <BR>> attributed the measurements but the switches are a<BR>> major contributor. <BR>><BR>>
<BR>>> SDR is an interesting field in radiocommunication<BR>>> <BR>> but I feel there is still a lot of work to be done as<BR>> we do have to learn on how to do measurements with<BR>> this kind of receivers contrary to the analog radio<BR>> equipment ...<BR>><BR>><BR>> They solved an early problem and we can thank Gerald<BR>> for finding this <BR>> part and his very gracious publication in QEX and with<BR>> the SDR-1000. <BR>><BR>> <BR>>> I would like to underline that I am the ONE that had<BR>>> <BR>> the idea, early 1998, to use the Fast Bus Switches<BR>> like the FST3125 in mixers to replace diodes and MOS<BR>> in particular for the G3SBI H-Mode Mixer. The Idea of<BR>> FST use did improve the Tayloe QSD.<BR>> <BR>> But it is time to leave them behind FOREVER.<BR>><BR>> <BR>>> Sorry but I do not understand your "FOREVER" in the<BR>>> <BR>> abouve phrase. Leave the Forever
for all radio project<BR>> or FOREVER for SDR ?<BR>><BR>> I believe we should never close any door to the past<BR>> or to the future. I am sure the HPSDR group will<BR>> rlease SDR project very advanced going totally with<BR>> digital solution ... but we should never forget we are<BR>> Amateur Radio and not Business, although there are<BR>> many involved in SDR that are also in the industry.<BR>><BR>> <BR>>> There are other colleges experimented with recent<BR>>> <BR>> switches like the FSA322 ... that may give H-Mode<BR>> Mixer with IP3 around +50dBm .... what will be the<BR>> value of IP3 in HPSDR?<BR>><BR>> Thanks and best 73<BR>><BR>> Gian<BR>> I7SWX<BR>><BR>> 73's<BR>> Bob<BR>> N4HY<BR>><BR>><BR>><BR>> <BR>> ____________________________________________________________________________________<BR>> Finding fabulous fares is fun. <BR>> Let Yahoo! FareChase search your
favorite travel sites to find flight and hotel bargains.<BR>> http://farechase.yahoo.com/promo-generic-14795097<BR>> _______________________________________________<BR>> HPSDR Discussion List<BR>> To post msg: hpsdr@hpsdr.org<BR>> Subscription help: http://lists.hpsdr.org/listinfo.cgi/hpsdr-hpsdr.org<BR>> HPSDR web page: http://hpsdr.org<BR>> Archives: http://lists.hpsdr.org/pipermail/hpsdr-hpsdr.org/<BR>><BR>> <BR><BR><BR>-- <BR>AMSAT Director and VP Engineering. Member: ARRL, AMSAT-DL,<BR>TAPR, Packrats, NJQRP, QRP ARCI, QCWA, FRC. ARRL SDR WG Chair<BR>"If you board the wrong train, it is no use running along the<BR>corridor in the other direction. " - Dietrich Bonhoeffer<BR><BR><BR><BR>------------------------------<BR><BR>Message: 7<BR>Date: Tue, 16 Jan 2007 15:29:49 +1100<BR>From: Geoff <VK2TFG@OZEMAIL.COM.AU><BR>Subject: [hpsdr] ADG901<BR>To: HPSDR Group <HPSDR@HPSDR.ORG><BR>Message-ID:
<45AC54BD.2050803@ozemail.com.au><BR>Content-Type: text/plain; charset=ISO-8859-1; format=flowed<BR><BR>Hi Guys,<BR>A couple of numpty questions (I fix machines for a living). Has <BR>anybody looked at the Analog Devices ADG901 as a QSD Switch? I can?t <BR>recall seeing it on the list. Has anybody identified a class of <BR>flip-flops suitable for QSD service above 30 or 40 MHz?<BR><BR>73 de Geoff vk2tfg.<BR><BR><BR>------------------------------<BR><BR>Message: 8<BR>Date: Tue, 16 Jan 2007 10:28:10 +0000<BR>From: Dan Andersson <DAN.ANDERSSON@IEEE.ORG><BR>Subject: Re: [hpsdr] ADG901<BR>To: hpsdr@hpsdr.org<BR>Message-ID: <200701161028.10988.dan.andersson@ieee.org><BR>Content-Type: text/plain; charset="iso-8859-1"<BR><BR>On Tuesday 16 January 2007 04:29, Geoff wrote:<BR>> ***** High Performance Software Defined Radio Discussion List *****<BR>><BR>> Hi Guys,<BR>> A couple of numpty questions (I fix machines for a living). Has<BR>> anybody looked at
the Analog Devices ADG901 as a QSD Switch? I can?t<BR>> recall seeing it on the list. Has anybody identified a class of<BR>> flip-flops suitable for QSD service above 30 or 40 MHz?<BR>><BR>> 73 de Geoff vk2tfg.<BR>> <BR><BR><BR>Geoff,<BR><BR>The ADG901 is on the slow side for Ton and Toff.<BR><BR><BR>=== message truncated ===</BLOCKQUOTE><BR>