Re: [Discuss-gnuradio] WBX power level

[Jason Abele]

On Tue, Jun 15, 2010 at 06:48:39PM +0100, Charles Brain wrote:
> >
> >Does your code set the transmit gain on the WBX?
> >
> >Eric
> 
> Yes to 25. I checked the range and set it to maximum.
> 
> - Charles

Charles,

In my test with USRP2 and UHD here in the lab, I am able to get similar
power output numbers to when I used usrp_siggen_gui.py.

Here are my best guesses:

Try my attached grc/python code for transmitting with gr-uhd, assuming
you have built a gnuradio from branch next, which includes gr-uhd.

Probe the voltage at R532, it should vary from 1.4V to 0.5V with
different transmit gain settings.  Ok, R532 is on the bottom, so instead
try probing at the via between the "2" and "1" in the C521 label (which
is near the C523 label).

> I am using my own code that writes directly to the UHD and I forced it to
> set the I channel to 0x7FFF
> and the Q channel to 0 and the gain to 25.

Its also possible your app is not sending the correct type data for that
DC tone. (ie, sending int on an interface expecting float)

see host/include/uhd/types/io_type.hpp

Jason

uhd-test-tx.grc
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uhd_test_tx.py
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