[USRP-users] Output power of E310

Claudio Cicconetti ccicconetti at mbigroup.it
Mon Mar 14 04:04:43 EDT 2016


On 03/11/2016 04:48 PM, Marcus D. Leech via USRP-users wrote:
> On 03/11/2016 06:08 AM, Claudio Cicconetti via USRP-users wrote:
>> Dear all,
>> We are working on a testbed for satellite communication where the
>> transmitter is an Ettus E310. Since we are dealing with the link budget,
>> we need to understand the maximum power that we can achieve.
>>
>> We have run a few experiments to gather a rough order of magnitude using
>> the tx_waveforms example (with --ampl 0.7 and --gain 89.8) and measuring
>> the output power with a spectrum analyzer.
>>
>> We have found the following results:
>>
>> 70  MHz -> -6 dBm
>> 1.5 GHz -> -17 dBm
>> 3   GHz -> 10 dBm <<< as per datasheet
>> 6   GHz -> 4 dBm
>>
>> The sample rate does not seem to play a role in the experiments.
>>
>> Do these results make sense to you? For instance, we would have expected
>> to have a monotone relationship between frequency and power...
>>
>> More important: since our application is expected to work at 1.5 GHz
>> (which accidentally achieves minimum output in our experiments) is there
>> any way to increase the output power in that frequency range?
>>
>> Best regards,
>> Claudio
>>
> Claudio:
> 
> This sounds like the wrong filters are being selected.  What system
> image are you using, and can you reproduce this behavior with
>   the latest system image?

Dear Marcus,
I used the image that came pre-installed in the SD card (I don't know
where to search the version number in there).

I can try installing the latest version and try again, as you suggest.

For the avoidance of doubt, does this mean:

1. building a new image from git as described in
http://files.ettus.com/manual/page_usrp_e3x0.html under "Rebuilding the
file system"; or

2. getting a pre-built image from http://files.ettus.com/e3xx_images/

If the option 2. is the correct one, can you please provide a pointer to
the correct image to copy to the SD?

Best regards,
Claudio





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