10 Mar
2013
10 Mar
'13
3:20 p.m.
Hi Joel.
2. What is the power output in dbm of your umtrx?
After fixing this
issue<https://code.google.com/p/umtrx/issues/detail?id=41&can=1&…
measured + 20 dBm for 900 MHz band and +17 dBm for 1800.
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:
GSM.Radio.PowerManager.MaxAttenDB 8
GSM.Radio.PowerManager.MinAttenDB 0
Please explain more what att do you try to use and what clipping do you
mean (may be 1dB gain compression) ?
Anyhow, you can easy adjust output signal of UmTRX by using --gain in case
of UHD TX control.
Also can be used TXVGA2 gain in case of direct LMS registers control via
Python scripts.
Is using an LNA with BPF advisable with your UMTRX?
Yes of course.
External LNA and duplexer or band pass filter should be used for better NF
performance.
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.
You can find on the board FUN2 control IC (U35)
MAX6665ASA45<http://datasheets.maximintegrated.com/en/ds/MAX6665.pdf>
.
So, at the PCB temperature +45'C FUN2 must start to cooling.
And if you do not use FAN2 (or broken) then this IC will switch off UmTRX
at temperature 45+30=75'C.
Low temperature limit is minus 40'C due to industrial components (is not
tested 100% in production).
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?
You can use any DC-DC output higher 2V through current limiting resistor.
Pleas refer to datasheet of your LED's type to find proper resistor value.
On Tue, Mar 5, 2013 at 10:16 AM, Andrey Sviyazov <andreysviyaz(a)gmail.com>wrote;wrote:
Best regards,
Andrey Sviyazov.
Hi Joel.
On Fri, Feb 22, 2013 at 6:28 PM, joel yabut <joel(a)jointventure.com>
wrote:
Not yet measured and
unfortunately there are no info from Lime Micro.
Andrey Sviyazov.
--
Mother Ignacia Avenue corner Scout Rallos St.
Quezon City, Metro Manila, Philippines
May i
know the following specs
1. What is the tx and rx isolation of umtrx?
2. What is the power output in dbm of your
umtrx?
After fixing this
issue<https://code.google.com/p/umtrx/issues/detail?id=41&can=1&…
measured + 20 dBm for 900 MHz band and +17 dBm for 1800.
3. How is the lna on the rx input and is an
external lna and bpf
recommended?
For Fairwaves 10W base stations we're developing UmSEL, which has
channel filter and an additional LNA. For the use without amplifier
you don't need any additional filters or LNAs.
4. What is the main advantage of umtrx compared
to usrp by ettus?
If you want to use it for GSM, then it's cheaper and gives you
dual-channel support.
--
Regards,
Alexander Chemeris.
CEO, Fairwaves LLC / ООО УмРадио
http://fairwaves.ru
Best regards,