UmTRX performance questions

Alexander Chemeris alexander.chemeris at
Sun Mar 10 20:16:45 UTC 2013


In addition to comments from Andrey:

On Sun, Mar 10, 2013 at 10:00 PM, joel yabut <joel at> wrote:
> 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

Yes, you could use these config values to control power output. Note,
that maximum output power is control by MinAttenDB and not MaxAttenDB,
because these are attenuation values.

> Is using an LNA with BPF advisable with your UMTRX?

It depends on you intended usage. For high power BTS you need them,
yes. At this moment we're designing a proper RF solution for UmTRX as
a part of our UmSITE hardware.

> 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.

It is designed to meet industrial temperature range, but only units
used for UmSITE will be tested during manufacturing. UmTRX's which are
sold as DIY kit are not tested and could be assumed to meet indoor
temperature range.

> 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 could use "Ext connector" or LED1/LED2/LED3 connectors. Please
check schematics for details.

Alexander Chemeris.
CEO, Fairwaves LLC / ООО УмРадио

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