LMS TxLO noise

Alexander Chemeris alexander.chemeris at gmail.com
Sun Jul 22 19:21:30 UTC 2012


On Sun, Jul 22, 2012 at 10:51 PM, Thomas Tsou <thomastsou at gmail.com> wrote:
> On Sun, Jul 22, 2012 at 12:59 AM, Alexander Chemeris
> <alexander.chemeris at gmail.com> wrote:
>> On Sun, Jul 22, 2012 at 6:40 AM, Thomas Tsou <thomastsou at gmail.com> wrote:
>>> On Sat, Jul 21, 2012 at 5:57 PM, Alexander Chemeris
>>> <alexander.chemeris at gmail.com> wrote:
>>>> I've started documenting this at the wiki:
>>>> http://code.google.com/p/umtrx/wiki/LMS6002DCalibration#Tx_I/Q_balance_calibration
>>>> Is that a good enough description for you?
>>>
>>> Added:
>>>
>>> - IQ balance correction
>>> - Laurent C1 pulse
>>>
>>> We are below the target threshold.
>>
>> Great achievement!
>> Is it consistent over the whole 900 band, i.e. is that the worst case?
>
> Overall measurements are close (either above or below) to 1.5/5 for
> the 900 band in general. 945 MHz is currently the best case, but that
> is the frequency I spent the most time on with calibration. Do we need
> to be consistently below 1.5/5 or just close?

Thanks for the measurements. At the end we should be below that at all
GSM bands. For now it's fine to be close.

I also noticed that your frequency is far off - could you calibrate it
and make pictures of the best and worst case in the 900 band?

And just to be sure - could you check what TCXO do you have on the
UmTRX? It should be TCD4029-26.0M, probably marked like PLEU4030Z.

-- 
Regards,
Alexander Chemeris.
CEO, Fairwaves LLC / ООО УмРадио
http://fairwaves.ru




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