<html><body><div style="color:#000; background-color:#fff; font-family:times new roman, new york, times, serif;font-size:12pt"><div><span></span></div><div>Helmut,</div><div> </div><div>Often wondered the same myself. I also thought that undersampling of narrowband FM or AM in this spectrum 140-166 would be handy for many uses (airband, amateur, etc)....which then took me toward the FM broadcast band also (is 88-108 too close to the LO?).</div><div> </div><div>Greg</div><div>nz8r<br><br><br><br></div><div><br><blockquote style="padding-left: 5px; margin-top: 5px; margin-left: 5px; border-left-color: rgb(16, 16, 255); border-left-width: 2px; border-left-style: solid;"> <div style="font-family: times new roman, new york, times, serif; font-size: 12pt;"> <div style="font-family: times new roman, new york, times, serif; font-size: 12pt;"> <div dir="ltr"> <div class="hr" style="margin: 5px 0px; padding: 0px; border: 1px solid rgb(204, 204,
204); height: 0px; line-height: 0; font-size: 0px;" contenteditable="false" readonly="true"></div> <font face="Arial" size="2"> <b><span style="font-weight: bold;">From:</span></b> "Helmut, DC6NY" <dc6ny@gmx.de><br> <b><span style="font-weight: bold;">To:</span></b> hpsdr@lists.openhpsdr.org <br> <b><span style="font-weight: bold;">Sent:</span></b> Wednesday, July 31, 2013 10:31 AM<br> <b><span style="font-weight: bold;">Subject:</span></b> [hpsdr] Mercury as VHF Receiver<br> </font> </div> <div class="y_msg_container"><br>
***** High Performance Software Defined Radio Discussion List *****<br><br>Hi ,<br><br>I did some tests with undersampling: For this purpose I bypassed the<br>antialiasing LP on one of my Mercuries and added an external helical BP<br>together with a low noise high OIP3 preamp. Selecting 122,9 MHz LO offset<br>plus error correction in the XVTR settings the entire 2m band can be<br>perfectly received. Stop-band attenuation in this preliminary experiment was<br>only around 80 dB, but can be certainly improved.<br>Moreover I think it makes sense to generate possibly the 2m-TX-signal with a<br>simple analog up-converter to get a complete 2m TRX without the classic<br>transverter configuration.<br><br>Comments and suggestions are welcome.<br><br>73, Helmut, DC6NY<br><br>_______________________________________________<br>HPSDR Discussion List<br>To post msg: <a href="mailto:hpsdr@openhpsdr.org"
ymailto="mailto:hpsdr@openhpsdr.org">hpsdr@openhpsdr.org</a><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></div> </div> </div> </blockquote></div> </div></body></html>