[Hackrf-dev] HackRF and SDR Console Vers 3

Discussion:

James Brown

2017-03-02 15:07:44 UTC

Is anyone using SDR Console to control HackRf?

I have a problem that is plaguing me and I canât decided if its SDR Console, drivers, or Hack RF hardware.

A set of signals that show up on the Spectrum display right in the middle regardless of the tuning.
They are not I/Q unbalance (I donât think), and they appear to be modulated in amplitude.
They are dependent of bandwidth selection but are sensitive to the setting of LNA and VGA gain.
You can see a screen grab here:
http://www.seti.net/engineering/notebook/volume-11/Chap68/chap68.php

Iâm running Windows 10 64 bit and using SDR Console dated Feb 21 2017, 64 bit

Regards...James Brown

Cinaed Simson

2017-03-02 20:35:53 UTC

Permalink

You should post the output from hackrf_info.

That is, we need to be convinced the libraries being used match the
firmware on the HackRF.

The HackRF as a DC offset at the center frequency.

There should always be something at the center frequency - besides the
signal of interest - so you will need to shift the center frequency so
it avoids the signal of interest.

Take a look at

http://www.greatscottgadgets.com/sdr

-- Cinaed

Post by James Brown
Is anyone using SDR Console to control HackRf?
I have a problem that is plaguing me and I can’t decided if its SDR
Console, drivers, or Hack RF hardware.
A set of signals that show up on the Spectrum display right in the
middle regardless of the tuning.
They are not I/Q unbalance (I don’t think), and they appear to be
modulated in amplitude.
They are dependent of bandwidth selection but are sensitive to the
setting of LNA and VGA gain.
http://www.seti.net/engineering/notebook/volume-11/Chap68/chap68.php
I’m running Windows 10 64 bit and using SDR Console dated Feb 21 2017,
64 bit
Regards...James Brown
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https://pairlist9.pair.net/mailman/listinfo/hackrf-dev

Fernando

2017-03-03 11:37:20 UTC

Permalink

I compile here some of the information I have gathered and set out some
questions I do not know

The FAQ explains that hack rf one have three amplifiers for reception (
RF, IF and BB) and two for transmission (RF and IF)
At RX: RF gain may be 0 or 14dB
IF (LNA) gain may be from 0 to 40 db in 8dB steps
BB (VGA) gain may be from 0 to 62dB in 2 db steps

They suggest using RF=0, IF=16, BB=16 as start point and change IF and
BB almost same amount up/down trying to achieve a gain so good you have
a good SNR but so low you don't have distortion
You must not use RF gain unless you are receiving a very week signal and
even so you must be sure there is no other signal out of your band of
interest with high power because if it is the case you can damage your
RF amplifier
Max RX power = -5dBm (In theory with the RF amplifier gain set to 0 it
can accept up to +10dBm but it is not recommended)

At TX
RF gain may be 0 or 14dB
IF gain may be from 0 to 47 dB in 1dB steps
There is no BB amplifier
You cant transmit without a correctly adapted antenna (for instance
without antenna) because impedance disadaptation may produce reflection
(without antenna 100% reflection) wich will create an overshoot and can
destroy the RF amplifier.
Max TX power depends on TX frequency
10 MHz to 2150 MHz: 5 dBm to 15 dBm, generally increasing as frequency
decreases
2150 MHz to 2750 MHz: 13 dBm to 15 dBm
2750 MHz to 4000 MHz: 0 dBm to 5 dBm, increasing as frequency decreases
4000 MHz to 6000 MHz: -10 dBm to 0 dBm, generally increasing as
frequency decrease

Taking in account all the precedent, I have two questions (indeed they
are very related)

What it the max amplification you can use for TX?
When using a osmocon sink in GNU Radio, how can we calc the power we are
using for transmision?

regards

Cinaed Simson

2017-03-03 09:19:25 UTC

Permalink

Also, turn off I/Q balance and DC offset and tune the receiver to 25.04
MHz - for instance - and see what happens.

-- Cinaed