UmTRX v1b coming soon

Jean-Samuel Najnudel - BJT PARTNERS SARL jsn at bjtpartners.com
Wed May 30 22:57:00 UTC 2012


Hi Andrey,

Thank you very much for your reply.

Yes, great idea. I think this really makes sense. Adding this amplifier
would be better in most cases and cannot be worse than just saturating the
LMS Tx without amplifier. Now I understand and fully agree with you.

Best regards.

Jean-Samuel.
:-)
 Le 30 mai 2012 22:28, "Andrey Sviyazov" <andreysviyaz at gmail.com> a écrit :

> Hi Jean-Samuel.
>
> Unfortunately nobody can say about isolation between Tx and Rx of the
> LMS6002 chip, about which I've told you.
> So, I decide to pre-amplify Tx because it can to reduce the output signal
> of the LMS.
> Anyway isolation of the PCB seems to be quite higher then inside LMS, I'm
> sure.
> And also, if I am wrong then we can bypass signal through C108-C109 to
> avoid this my mistake.
>
> Best regards,
> Andrey Sviyazov.
>
>
>
> 2012/5/30 Jean-Samuel Najnudel - BJT PARTNERS SARL <jsn at bjtpartners.com>
>
>> Hi Andrey,
>>
>> Thank you for your e-mail.
>>
>> This is a great news. Great ideas, great debug, great improvements.
>> Thanks a lot.
>>
>> The board looks fine but I will see in deeper details and let you know.
>>
>> A question just comes to my mind.
>> 20 dBm Tx output is very convenient. This would allow to saturate and
>> achieve a very good PA efficiency. This is really nice.
>> In case Tx output is 20 dBm are you sure we would not have any PCB Tx
>> signal leakage problems ?
>> A few months ago, you told me maximum Tx power was around 0 dBm to avoid
>> problems. Did you find a solution to improve isolation and allow the 20 dBm
>> Tx power ?
>>
>> Anyway, thanks a lot. Again, the board seems to be really great. This
>> would also bring a wonderful tool to the SDR, OpenBTS and OpenBSC
>> communities. Thank you so much for this.
>>
>> Best regards.
>>
>> Jean-Samuel.
>> :-)
>>
>>
>>
>> On Tue, May 29, 2012 at 7:59 PM, Andrey Sviyazov <andreysviyaz at gmail.com>wrote:
>>
>>> Hi all.
>>>
>>> First of all, Alexander asked me to use UmTRXv2 instead of v1b, so
>>> project renamed and I'll send whole project later.
>>> Here "What new in UmTRXv2.txt" in addition to fixed of all known
>>> UmTRXv1a issues<http://code.google.com/p/umtrx/issues/list?can=1&q=&colspec=ID+Type+Status+Priority+Milestone+Owner+Summary+Modified&cells=tiles>
>>> .
>>> Unfortunately, a lot physical changes between v1a and v2 and it is very
>>> difficult to me to explain all step-by-step in details.
>>> But I am ready to patiently answer for any kind of questions.
>>> Here also EEpromConfig.SchDoc and BOM files which changed because C298
>>> should be Case-A (issue 18<http://code.google.com/p/umtrx/issues/detail?id=18&can=1&colspec=ID%20Type%20Status%20Priority%20Milestone%20Owner%20Summary%20Modified>
>>> ).
>>>
>>> Best regards,
>>> Andrey Sviyazov.
>>>
>>>
>>>
>>> 2012/5/29 Andrey Sviyazov <andreysviyaz at gmail.com>
>>>
>>>> Here PDF's
>>>>
>>>> Best regards,
>>>> Andrey Sviyazov.
>>>>
>>>>
>>>>
>>>> 2012/5/29 Andrey Sviyazov <andreysviyaz at gmail.com>
>>>>
>>>>> Here PCB file of project.
>>>>>
>>>>> Best regards,
>>>>> Andrey Sviyazov.
>>>>>
>>>>>
>>>>>
>>>>> 2012/5/29 Andrey Sviyazov <andreysviyaz at gmail.com>
>>>>>
>>>>>> Hi all.
>>>>>>
>>>>>> First release of UmTRXv1b seems finished.
>>>>>> All suggestions and issues are welcomed, especially prior to
>>>>>> production (few days).
>>>>>> There are 4 Rx inputs to implement either scan function or software
>>>>>> diversity receiving.
>>>>>> There are 16pin connector to supply and control external preselector,
>>>>>> amplifier, LNA, ATT, diversity switch...
>>>>>> This new release have 2U size (100x160mm) that more universal for
>>>>>> indoor housing to put together several UmTRX's with PC and power supply
>>>>>> modules in one rack.
>>>>>> Also possible variant to meet to requirements -40C and it is the only
>>>>>> one reason to keep OCVCXO onboard.
>>>>>> Also possible variant with external control panel to make easily IP65
>>>>>> housing design.
>>>>>> Also DC supply voltage can be in range 8..28V to keep single DC
>>>>>> supply if UmTRX will combined with IP65 tower mounted amplifiers.
>>>>>>
>>>>>> And so on depend of your fantasy :)
>>>>>>
>>>>>> Here included some project files and BOM for variant with 20dBm Tx
>>>>>> and onboard control.
>>>>>> PCB and PDF files will be in the next two e-mails.
>>>>>>
>>>>>> Best regards,
>>>>>> Andrey Sviyazov.
>>>>>>
>>>>>>
>>>>>>
>>>>>> 2012/5/21 Alexander Chemeris <alexander.chemeris at gmail.com>
>>>>>>
>>>>>>> Andrey,
>>>>>>>
>>>>>>> On Sun, May 20, 2012 at 6:46 PM, Andrey Sviyazov <
>>>>>>> andreysviyaz at gmail.com> wrote:
>>>>>>> > 1) Is it used somewhere? In the datasheet there is probable
>>>>>>> errors, for
>>>>>>> > example, 1PPS is specified as input.
>>>>>>>
>>>>>>> Use this datasheet, here it's marked as output:
>>>>>>>
>>>>>>> http://www.transystem.com.tw/product/66/EB-570%20Data%20Sheet%20V1.4.pdf
>>>>>>> Probably you have an older version of the datasheet.
>>>>>>>
>>>>>>> > 2) There are inputs Reset and Standby. The first can be left open,
>>>>>>> and the
>>>>>>> > second is possible need to be connected to to FPGA.
>>>>>>>
>>>>>>> Yes.
>>>>>>>
>>>>>>> > 3) There Is RTC_CLK_O we don't need him? And that there may be,
>>>>>>> 32768?
>>>>>>>
>>>>>>> Could you route it to a test-point or a 2-pin IDC? I don't think we
>>>>>>> need this, but it's better to have an ability to access it.
>>>>>>>
>>>>>>> > 4) Which of two UART's better to use or are they equivalent? There
>>>>>>> are no
>>>>>>> > any words in datasheet about it.
>>>>>>>
>>>>>>> Use TX0/RX0 (pins 13/14), which is default to NMEA - see the
>>>>>>> datasheet above.
>>>>>>>
>>>>>>> > 5) Unfortunately no place for both on PCB and we can use either
>>>>>>> EB-230 or
>>>>>>> > EB-570.
>>>>>>>
>>>>>>> Then we have to use EB-570.
>>>>>>>
>>>>>>>
>>>>>>> --
>>>>>>> Regards,
>>>>>>> Alexander Chemeris.
>>>>>>> CEO, Fairwaves LLC / ООО УмРадио
>>>>>>> http://fairwaves.ru
>>>>>>>
>>>>>>
>>>>>>
>>>>>
>>>>
>>>
>>
>
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