Re: [Openbts-discuss] mini USRP & mini RFX900/1800

[Alexander C. <ale...@gm...>]

Jongjay, you occasionally sent this mail to me instead of the mailing list.


---------- Forwarded message ----------
From: Jongjay Liou <jon...@ho...>
Date: Tue, Nov 1, 2011 at 04:18
Subject: RE: [Openbts-discuss] mini USRP & mini RFX900/1800
To: Alexander Chemeris <ale...@gm...>


First of all, I have been warned by Matt Ettus and he threatening to
take legal action again me. I am not sure what to do next.
Now, regarding your question:

I use Agilent 4406 VSA measured, radiating with OpenBTS s/w, the
average power is betweem -4.3 ~-3.95 dBm since GSM signal is modulated
digital signal. First time I gave you ~-15dBm because 2nd stage RF3315
was not working properly, RFX has two stage signal drive before it
pump to TX/RX port, 1st stage is MGA-82563 which is very easy to get
toasted, the 2nd stage is RF3315, and we thoght all the inductor and
capacitor has something to do with output power, they don't, and of
course the microstrip impedance matching between 1st rf driver and 2nd
stage rf driver. Anyway, if MGA-82563 and RF3315 works ok and
microstrip working ok, then the output power should have around -4dBm,
I made another PC board which measured ~-9dbm with all active/passive
components working ok, I belive that is caused by microstrip impedance
matching, blame it to PCB manufacturer. Hope this explains.

52Mhz clock, the accuracy is 0.05ppm 30 days after shipping, long
stability and aging data I will give you later this week. It is custom
made with Chinese national standard class 2 accuracy, the order takes
at least 6~8 weeks because they need to do aging before shipping, same
clock manufacturer made clock for Huawei and ZTE and defense
contractor in China. It took me some effort to get agreement with
them.

Since I am on a business trip won't be back till this weekend, I will
provide more technical and some more picture later, remember to
measure 0.05ppm clock accuracy it takes special instrument to do that,
it means you must have 0.0005ppm or 0.005 accuracy instrument to know
how accurate the DUT clock is, I don't have that instrument in my lab.
I went to my supplier and I used this clock myself so I send you that
information.

Stay tune...

> From: ale...@gm...
> Date: Mon, 31 Oct 2011 19:39:45 +0400
> Subject: Re: [Openbts-discuss] mini USRP & mini RFX900/1800
> To: jon...@ho...
> CC: ope...@li...
>
> Do you actually mean that maximum output power is -4dBm, which is 0.4mW?
>
> What exactly does your "0.05 ppm" mean in the OCXO specs? Is it
> initial calibration accuracy, or temperature stability, or overall
> stability for 1year, or something else? It would be helpful if you
> share the whole PDF of the OCXO. This value alone doesn't seem to be
> useful.
>
> 2011/10/31 Jongjay Liou <jon...@ho...>:
> > Hello Community,
> >
> > We have developed Ettus USRP1 compatible mini USRP1 and mini RFX900/1800 for
> > GSM application.
> > If you are interested, please let me know (jon...@ho...).
> > This is not really a marketing ad, we just want to offer this
> > community another h/w solution.
> >
> > Hardware info:
> > (Mini RFX 900/1800)
> > - 100% compatible with Ettus RFX900/1800
> > - replace Molex with 40-pin Milli-Grid connector
> > - Maximum TX output power -4dBm
> > - low working temp, around 113 Fahrenheit
> > - RF-4 Hi quality PCB (Au based)
> > - board dimension 56x98mm
> >
> > (Mini USRP)
> > - 100% compatible with Ettus USRP1
> > - replace Molex with Milli-Grid pin connector
> > - require external oscilator
> > - low working temp, around 104 Fahrenheit
> > - 100% compatible with gnuradio
> > - RF-4 Hi quality PCB (Au based)
> > - board dimension 118x97mm (~40% < USRP1)
> >
> > * mini USRP chip side and mini RFX chip side are on opposite
> >   side, which is designed for better heat dissipation in commercial
> > application
> >
> > (52MHz OCXO Oscilator)
> > - accuracy 0.05 ppm
> > - phase noise <= -135 dBc/Hz @1Khz
> > - input 5V
> > - square wave
> > - power on current 0.7A, operating current 0.3A
> > - sma connector
> > - size 52x42x18mm (~40% < RFX900)
> >
> >
> > Best regards,
> >
> > Jongjay Liou +86-18662697077
> > Kunshan eWave Co. Ltd.
> > Tel +86-512-50190031
> > Fax +86-512-50190032
> > jon...@ho...
> >
> > ------------------------------------------------------------------------------
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> >
> > _______________________________________________
> > Openbts-discuss mailing list
> > Ope...@li...
> > https://lists.sourceforge.net/lists/listinfo/openbts-discuss
> >
> >
>
>
>
> --
> Regards,
> Alexander Chemeris.



-- 
Regards,
Alexander Chemeris.