<div dir="ltr">Hello Roderick,<div><br></div><div>Please remember that the 2 RX in the Hermes-Lite and 5 RX in the Hermes use the same input and ADC. So 1 detector lets you listen to multiple bands on the same antenna. If you are interested in an inexpensive VNA, checkout another project of mine: <a href="https://code.google.com/p/pysdrvna/">https://code.google.com/p/pysdrvna/</a></div>
<div><br></div><div>73,</div><div><br></div><div>Steve</div><div>KF7O</div><div><br></div></div><div class="gmail_extra"><br><br><div class="gmail_quote">On Wed, Apr 16, 2014 at 2:52 AM, <span dir="ltr"><<a href="mailto:rodwall1234@gmail.com" target="_blank">rodwall1234@gmail.com</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
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<div dir="ltr" style="font-family:'Calibri','Segoe UI','Meiryo','Microsoft YaHei UI','Microsoft JhengHei UI','Malgun Gothic','sans-serif';font-size:12pt"><div>Hi Steve,</div>
<div><br></div><div>Thanks for your reply. As I’ve indicated, a VNA for $150.00 would be great. And if it can have two Rx detectors it would be even better to do Reflection and Transmission measurements with out having to change the connections to the DUT.</div>
<div><br></div><div>Good luck with the development, I’ll like to build one and help test it when ready.</div><div><br></div><div>Regards,</div><div><br></div><div>Roderick Wall, vk3yc.</div><div><br></div><div style="padding-top:5px;border-top-color:rgb(229,229,229);border-top-width:1px;border-top-style:solid">
<div><font face=" 'Calibri', 'Segoe UI', 'Meiryo', 'Microsoft YaHei UI', 'Microsoft JhengHei UI', 'Malgun Gothic', 'sans-serif'" style="line-height:15pt;letter-spacing:0.02em;font-family:"Calibri","Segoe UI","Meiryo","Microsoft YaHei UI","Microsoft JhengHei UI","Malgun Gothic","sans-serif";font-size:12pt"><b>From:</b> <a href="mailto:steve@softerhardware.com" target="_blank">Steve Haynal</a><br>
<b>Sent:</b> Wednesday, 16 April, 2014 1:48 PM<br><b>To:</b> <a href="mailto:hpsdr@openhpsdr.org" target="_blank">hpsdr@openhpsdr.org</a></font></div></div><div><br></div><div dir=""><div dir="ltr">Yes, the Hermes-Lite should be usable as a VNA, although I have not tested this. Currently, it runs in half-duplex mode. I tried full-duplex but had some issues with noise at various front-end gain levels. I have asked ADI for help with this. You will have to use full-duplex for the VNA and the levels of noise I saw probably won't matter much for a VNA. Ideally, I'd like to see half-duplex for regular operation to keep the power consumption low, and then switch to full-duplex when needed for a VNA.<div>
<br></div><div>The design is now only 1 RX and 1 TX to keep the compile time down. The limitation yo will run into when compiling with 2 RX and 1 TX is not enough RAM resources. The Hermes had some large buffers because I believe it could. These will have to be reduced to fit 2 RX and 1 TX.</div>
<div><br></div><div>73, </div><div><br></div><div>Steve</div><div>KF7O</div><div><br></div></div>
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