<html><head></head><body bgcolor="#FFFFFF"><div>Yes i need to attenuate the tx output and Also take into consideration the 1 db compression. I just have to </div><div> min attenuation to 8.<br><br>Sent from my Ipad</div><div><br>On Mar 11, 2013, at 3:20 AM, Andrey Sviyazov <<a href="mailto:andreysviyaz@gmail.com">andreysviyaz@gmail.com</a>> wrote:<br><br></div><div></div><blockquote type="cite"><div>Hi Joel.<div><br><div class="gmail_quote"><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="ltr"><div><div class="im"><div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">
> 2. What is the power output in dbm of your umtrx?<br></blockquote></div><div>After fixing <a href="https://code.google.com/p/umtrx/issues/detail?id=41&can=1&colspec=ID%20Type%20Status%20Priority%20Milestone%20Owner%20Summary%20Modified" target="_blank">this issue</a> I measured + 20 dBm for 900 MHz band and +17 dBm for 1800.</div>
<div> <br></div></div><div>I will be testing this UMTRX with a DCS amp with 10 dBM input. Just to be sure, I just need to adjust attenuation to at least 7 dBM and 8 probably to avoid clipping the RF amp as below:<br><br>
GSM.Radio.PowerManager.MaxAttenDB 8
<br>GSM.Radio.PowerManager.MinAttenDB 0
<br></div></div></div></blockquote><div><br></div><div>Please explain more what att do you try to use and what clipping do you mean (may be 1dB gain compression) ?</div><div>Anyhow, you can easy adjust output signal of UmTRX by using --gain in case of UHD TX control.</div>
<div>Also can be used TXVGA2 gain in case of direct LMS registers control via Python scripts.</div><div><br></div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="ltr">
<div><div><br></div><div>Is using an LNA with BPF advisable with your UMTRX? <br></div></div></div></blockquote><div>Yes of course.</div><div>External LNA and duplexer or band pass filter should be used for better NF performance.</div>
<div> </div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="ltr"><div><div><br></div>What is the operating temperature of your UMTRX as I want to make sure the HD case I am using for testing is good enough. I installed a small fan and so far temperature is around 40 deg C.<br>
</div></div></blockquote><div><br></div><div>You can find on the board FUN2 control IC (U35) <a href="http://datasheets.maximintegrated.com/en/ds/MAX6665.pdf">MAX6665ASA45</a>.</div><div>So, at the PCB temperature +45'C FUN2 must start to cooling.</div>
<div>And if you do not use FAN2 (or broken) then this IC will switch off UmTRX at temperature 45+30=75'C.</div><div>Low temperature limit is minus 40'C due to industrial components (is not tested 100% in production).</div>
<div><br></div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="ltr"><div>
<br></div><div>The LEDs are on the board and I may want to solder some LEDs to monitor status, where on the board can I terminate the power for LEDs?<br></div></div></blockquote><div><br></div><div>You can use any DC-DC output higher 2V through current limiting resistor.</div>
<div>Pleas refer to datasheet of your LED's type to find proper resistor value.</div><div><br></div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="ltr">
<div></div></div><div class="gmail_extra"><div><div class="h5"><br><br><div class="gmail_quote">
On Tue, Mar 5, 2013 at 10:16 AM, Andrey Sviyazov <span dir="ltr"><<a href="mailto:andreysviyaz@gmail.com" target="_blank">andreysviyaz@gmail.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
<div>Hi Joel.</div><div><div><br></div>On Fri, Feb 22, 2013 at 6:28 PM, joel yabut <<a href="mailto:joel@jointventure.com" target="_blank">joel@jointventure.com</a>> wrote:<br></div><div class="gmail_quote">
<div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
> May i know the following specs<br>
> 1. What is the tx and rx isolation of umtrx?<br></blockquote></div><div>Not yet measured and unfortunately there are no info from Lime Micro.</div><div><div><br></div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
> 2. What is the power output in dbm of your umtrx?<br></blockquote></div><div>After fixing <a href="https://code.google.com/p/umtrx/issues/detail?id=41&can=1&colspec=ID%20Type%20Status%20Priority%20Milestone%20Owner%20Summary%20Modified" target="_blank">this issue</a> I measured + 20 dBm for 900 MHz band and +17 dBm for 1800.</div>
<div>
<div> </div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
<br>
> 3. How is the lna on the rx input and is an external lna and bpf<br>
> recommended?<br>
<br>
For Fairwaves 10W base stations we're developing UmSEL, which has<br>
channel filter and an additional LNA. For the use without amplifier<br>
you don't need any additional filters or LNAs.<br>
<br>
> 4. What is the main advantage of umtrx compared to usrp by ettus?<br>
<br>
If you want to use it for GSM, then it's cheaper and gives you<br>
dual-channel support.<br>
<br>
--<br>
Regards,<br>
Alexander Chemeris.<br>
CEO, Fairwaves LLC / ООО УмРадио<br>
<a href="http://fairwaves.ru" target="_blank">http://fairwaves.ru</a><br>
<br>
</blockquote></div></div><div><div>Best regards,<div>Andrey Sviyazov.</div></div></div>
</blockquote></div><br><br clear="all"><br></div></div><span class="HOEnZb"><font color="#888888">-- <br>Mother Ignacia Avenue corner Scout Rallos St.<br>Quezon City, Metro Manila, Philippines<br><br>
</font></span></div>
</blockquote></div><br></div><div><div>Best regards,<div>Andrey Sviyazov.</div></div></div><div><br></div>
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