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Good idea.<br>I agree that.<br><br>73, Maximo - EA1DDO<br><br> <br><br><br><div>> From: getpri@t-online.de<br>> To: o.orcinus@gmail.com<br>> Date: Wed, 5 Oct 2011 11:34:00 +0200<br>> CC: hpsdr@lists.openhpsdr.org<br>> Subject: Re: [hpsdr] VHF/UHF transverter for HPSDR<br>> <br>> ***** High Performance Software Defined Radio Discussion List *****<br>> <br>> Hi Ante,<br>> <br>> I would like to bring up following question:<br>> Why not to develop a transverter for VHF/UHF? It would not only save<br>> space on our limited Atlas backplane but also engineering power. For<br>> those who don't need the TX-part could populate the RX-part only.<br>> <br>> 73, Georg, dl2kp<br>> <br>> <br>> <br>> On Sa, 2011-10-01 at 22:52 +0200, Ante Vukorepa wrote:<br>> > ***** High Performance Software Defined Radio Discussion List *****<br>> > <br>> > On srijeda, 21. rujna 2011. at 23:18, Ante Vukorepa wrote:<br>> > > 1) using Si570 (high grade LVDS version, if possible) as the LO to<br>> > > feed a high IP3 Mini Circuits frequency mixer, then filtering out<br>> > > the higher "image" with a 500MHz-ish low pass filter<br>> > > B1 is probably the best option for initial experimentation and my<br>> > > own (not very demanding) purposes. So that's the route i think i'll<br>> > > go, as soon as i catch some free time and start putting all this<br>> > > down on paper. My plan is to try and design a down converter<br>> > > consisting of fore-mentioned elements (Si570, frequency mixer,<br>> > > filter) plus a microcontroller, that would fit an Atlas card and<br>> > > would be controlled through the bus, via I2C. The vision is to have<br>> > > the ability to bypass and turn all the elements, including the<br>> > > microcontroller, off when not in use, so the impact on the existing<br>> > > HF signal chain is minimal.<br>> > <br>> > <br>> > I've put together an initial block diagram for what i've had in mind:<br>> > http://dl.dropbox.com/u/1702513/Block.png<br>> > <br>> > <br>> > The board will be 2-layer if possible (to simplify and cheapify things<br>> > initially), with one side dedicated almost purely to ground (separate<br>> > analogue and digital ground planes, of course, perhaps even a<br>> > completely separate plane for the Si570). Omron SMD signal relays will<br>> > be used for pre-amp and filter bypassing and oven control (control in<br>> > the sense of having it completely on or off, not in the sense of PWM).<br>> > An Atmega168 or 328 will control both them and the Si570 providing the<br>> > LO frequency. The Atmega will, in turn, be controlled via an I2C or<br>> > SPI line, by the other boards on the bus, or manually, via a front<br>> > control panel consisting of a rotary encoder, LCD and a few buttons.<br>> > The balun is there to convert the differential Si570 CML output and<br>> > suck out as much decibels as possible to feed a high IP3 frequency<br>> > mixer. The (optional) FM broadcast band-stop filter is there to kill<br>> > the interference from strong nearby FM towers, if needed.<br>> > <br>> > <br>> > How am i doing so far?<br>> > <br>> > -- <br>> > Ante Vukorepa<br>> > Sent with Sparrow<br>> > <br>> > <br>> > <br>> > <br>> > _______________________________________________<br>> > HPSDR Discussion List<br>> > To post msg: hpsdr@openhpsdr.org<br>> > Subscription help: http://lists.openhpsdr.org/listinfo.cgi/hpsdr-openhpsdr.org<br>> > HPSDR web page: http://openhpsdr.org<br>> > Archives: http://lists.openhpsdr.org/pipermail/hpsdr-openhpsdr.org/<br>> <br>> <br>> _______________________________________________<br>> HPSDR Discussion List<br>> To post msg: hpsdr@openhpsdr.org<br>> Subscription help: http://lists.openhpsdr.org/listinfo.cgi/hpsdr-openhpsdr.org<br>> HPSDR web page: http://openhpsdr.org<br>> Archives: http://lists.openhpsdr.org/pipermail/hpsdr-openhpsdr.org/<br></div> </div></body>
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