[Hackrf-dev] Low TX power

Paul Connolly eeipcy at gmail.com
Sat Jan 31 11:03:31 EST 2015


Are using -c 127 as an argument for your testing. And -x goes from 0 to
47dB, why stop at 14dB ?
$ hackrf_transfer
receive -r and receive_wav -w options are mutually exclusive
Usage:
... snip ...
        [-l gain_db] # RX LNA (IF) gain, 0-40dB, 8dB steps
        [-g gain_db] # RX VGA (baseband) gain, 0-62dB, 2dB steps
*        [-x gain_db] # TX VGA (IF) gain, 0-47dB, 1dB steps*
... snip ...
        [-c amplitude] # CW signal source mode, amplitude 0-127 (DC
value to DAC).
... snip ...
$

From https://github.com/mossmann/hackrf/wiki/HackRF-One#transmit-power
you should be seeing about 15dBm that close to 10MHz

It could be that you have damaged the TX amplifier, did you have -a 0 in
your tests. Because if it is broken then it would probably act like an
attenuator.

Paul

On 31/01/2015 12:43, Mark Jessop wrote:
> Hi all,
>
> Bought a HackRF a few months back, never properly measured the output power
> on it when I got it unfortunately, but it has certainly dropped at some
> point in the last few months.
>
> I finally got the chance to put it on a spectrum analyzer the other day.
> Transmitting a single carrier, I'm seeing a maximum of -30dBm output power
> at 14MHz. Only a few dB difference noticed when turning the RF Gain setting
> from 0 to 14dBm (This does actually do something, doesn't it?)
>
> Any thoughts? I have the facilities to replace QFN components if required...
>
> Cheers,
> Mark VK5QI
>
>
>
> _______________________________________________
> HackRF-dev mailing list
> HackRF-dev at greatscottgadgets.com
> https://pairlist9.pair.net/mailman/listinfo/hackrf-dev

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