Gnu radio with a soundcard

GNU Radio
1

Hi all,

Can someone explain how we may build a FM/SW receiver using A/D D/A
converter in a sound card and minimal additional hardware? Somewhere I
have read that this is possible, in principle, but could not yet gather
info suitable for a novice.

Thanks for the help.

Cheers,
Mathew

2

Mathew George wrote:

Hi all,

Can someone explain how we may build a FM/SW receiver using A/D D/A converter in a sound card and minimal additional hardware? Somewhere I have read that this is possible, in principle, but could not yet gather info suitable for a novice.

I am attempting the same general thing. I am pretty sure you will need
a radio receiver that has an IF output. My AOR 8200 has a discriminator
output which I think is something different. In theory it has an IF
output also but have not seen anything showing how to use it.

John

3

John R. wrote:

I am attempting the same general thing. I am pretty sure you will need
a radio receiver that has an IF output. My AOR 8200 has a discriminator
output which I think is something different. In theory it has an IF
output also but have not seen anything showing how to use it.

John

Well, I´m sure you´ll have to decide on what you want, because great FM
sound by feeding something through a sound card isn´t sounding
realistic.

You can not get more informations per second generally from a
soundcards´ output than you put in the input, roughly…

So you could detect and such signals which could be sampled from some
receiver if the bandwith would be limited to what a soundcard can
digitize, so without aliasing that would be 20kHz or maybe higher. The
intermedeate frequency in radios would be much higher, more megaherzes

A discriminator output may be applicable, but the processing of such a
signal into a FM decoded signal may not be what sr is usually used for.

In most cases the much higher sampling rate of the hardware device for
sr is needed to get a demodulatable signal I think, as well the
soundcard input may have not right impedances compared with radio
boards.

Very low frequency signals could be AD converted by soundcard, or a
signal with small bandwidth mixed into the audio band.

Theo

4

For Shortwave / HF bands, try ZetaSDR [1], SoftRock [2] or YU1LM [3]
designs.

Regards,

Rakesh

[1] http://www.qrz.lt/ly1gp/SDR/
[2] http://www.softrockradio.org/
[3] http://yu1lm.qrpradio.com/