UmTRX v1b coming soon

Andrey Sviyazov andreysviyaz at gmail.com
Wed May 30 20:28:32 UTC 2012


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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