| Author |
Message |
Jerry Avins
Guest
|
 Posted:
Tue Nov 29, 2005 1:16 am Post subject:
Re: Building a (cheap) software radio |
|
|
Michel Rouzic wrote:
| Quote: | Jerry Avins wrote:
You *said* that you want to input an FM channel to your PC sound system.
None of the links here deal with FM, and all the hardware described
delivers audio.
I didn't even understand that. seems like i ain't gonna get to what i
wanted
|
Probably not, but you can have something else nifty instead. You need to
understand what's being offered, instead of jumping to conclusions. For
now, I suggest you get a copy of /The Radio Amateur's Handbook/ from the
ARRL. http://www.arrl.org/catalog/?words=handbook What you're looking at
isn't "software radio", but "software defined radio". Big difference!
There's probably more satisfaction to be had from understanding how
something works than there is from making it work without knowing the
details. Doing both is really marvelous.
Jerry
--
Engineering is the art of making what you want from things you can get.
ŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻ |
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Michel Rouzic
Guest
|
| Posted:
Tue Nov 29, 2005 1:16 am Post subject:
Re: Building a (cheap) software radio |
|
|
Christen Fihl wrote:
| Quote: | I tried the SoftRock40 myself.
I bought a kit for $28, assembled it i 3 hours, and connected it to the
antenna and PC, and it worked right away.
See specs and more on: http://www.amqrp.org/kits/softrock40/
It is sold out by now, but would be easy to copy anyway.
|
"Orders are now being accepted for SoftRock v5.0 kit deliveries
starting at the end of November." think I should order it?
| Quote: | The receiver is fixed on one frequency, making "only" a bandwith of
20KHz into a PC soundcard, ready for a Software Defined Radio, like
http://www.flex-radio.com/
|
At last someone understood what I wanted to do!
| Quote: | Others have added an AnalogDevice DDS (0 to 60MHz) to it, see:
http://www.njqrp.org/dds/ making variable frequency all over.
Will set you back with another $28 (plus a free sample from
AnalogDevice)
This still leave you with $4 left in you pockets ;-)
|
um... with a softrock 5.0 and a DDS, what kind of thing could I do, and
also, what kind of antenna would I need? |
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|
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Michel Rouzic
Guest
|
| Posted:
Tue Nov 29, 2005 1:16 am Post subject:
Re: Building a (cheap) software radio |
|
|
Jerry Avins wrote:
| Quote: | You *said* that you want to input an FM channel to your PC sound system.
None of the links here deal with FM, and all the hardware described
delivers audio.
|
I didn't even understand that. seems like i ain't gonna get to what i
wanted
| Quote: | Others have added an AnalogDevice DDS (0 to 60MHz) to it, see:
http://www.njqrp.org/dds/ making variable frequency all over.
Will set you back with another $28 (plus a free sample from
AnalogDevice)
This still leave you with $4 left in you pockets ;-)
um... with a softrock 5.0 and a DDS, what kind of thing could I do, and
also, what kind of antenna would I need?
Jerry
--
Engineering is the art of making what you want from things you can get.
ŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻ |
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Christen Fihl
Guest
|
| Posted:
Tue Nov 29, 2005 1:16 am Post subject:
Re: Building a (cheap) software radio |
|
|
| Quote: | At last someone understood what I wanted to do!
Thanks |
You once wrote you wanted something like:
| Quote: | AM, FM, SSB, why not TV too, nothing precise
|
and you also asked:
| Quote: | .... starting at the end of November." think I should order it?
|
Depends on how wideband you want, and how high in frequency.
Wideband commercial FM around 100MHz cannot be received with SoftRock.
- Too high a frequency (easy to modify with other components), but still
fixed on xtal frequency or use a DDS.
- Too wide to decode in a normal soundboard, which always can do 44.1KHz
samples (about 20KHz bandwith decoded).
With a 96KHz sampler, you can get 40KHz (Google "soundboard 96KHz" and
find
http://www.natch.co.uk/downloads/SigJenny/usingsjn/Soundboard/Soundboard.html)
Or spend more money on "Creative Sound Blaster Audigy 4 Pro Limited
Edition" 192KHz sampling, I would not try this, as I like cheap too.
Wideband FM is out.
Seattle for narrowband, something like 5KHz. That leaves the whole
shortwave area. Do start out on a fixed range like SoftRock, DDS later
maybe.
Besides AM, FM, SSB, you can do TV (slowscan, called SSTV not real TV)
Morse, PSK, RTTY,
PSK is fun. It is narrowband, about 100Hz. Terminal mode with 31baud
data. In a normal voicewidth of 3KHz, you can have many active users
simultaniously. Very easy to see on a waterfall display.
SSTV: See some pictures on http://www.hffax.de/Destination.htm and
http://www.oz6sstv.dk/
See http://www.ncdxf.org/Beacon/bandplan.html for which signals are
normally send on each ham band. 7.040MHz is SSTV etc.
| Quote: | .... starting at the end of November." think I should order it?
For wideband FM, then no! |
Anything else on shortwave, sure.
| Quote: | um... with a softrock 5.0 and a DDS, what kind of thing could I do,
and also, what kind of antenna would I need?
Start with fixed frequency SoftRock. You still have many signals to play |
with.
For antenna, throw some wire out the windows into a tree, and you got
plenty of signal.
Have fun with it. I sure have ;-)
--
Christen Fihl
http://oz1aab.Fihl.net/ |
|
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|
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Jerry Avins
Guest
|
| Posted:
Tue Nov 29, 2005 1:16 am Post subject:
Re: Building a (cheap) software radio |
|
|
Michel Rouzic wrote:
| Quote: | Christen Fihl wrote:
I tried the SoftRock40 myself.
I bought a kit for $28, assembled it i 3 hours, and connected it to the
antenna and PC, and it worked right away.
See specs and more on: http://www.amqrp.org/kits/softrock40/
It is sold out by now, but would be easy to copy anyway.
"Orders are now being accepted for SoftRock v5.0 kit deliveries
starting at the end of November." think I should order it?
The receiver is fixed on one frequency, making "only" a bandwith of
20KHz into a PC soundcard, ready for a Software Defined Radio, like
http://www.flex-radio.com/
At last someone understood what I wanted to do!
|
You *said* that you want to input an FM channel to your PC sound system.
None of the links here deal with FM, and all the hardware described
delivers audio. It would be easier to understand what you want to do if
you didn't say you want to do something else.
| Quote: | Others have added an AnalogDevice DDS (0 to 60MHz) to it, see:
http://www.njqrp.org/dds/ making variable frequency all over.
Will set you back with another $28 (plus a free sample from
AnalogDevice)
This still leave you with $4 left in you pockets ;-)
um... with a softrock 5.0 and a DDS, what kind of thing could I do, and
also, what kind of antenna would I need?
|
Jerry
--
Engineering is the art of making what you want from things you can get.
ŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻ |
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|
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Jerry Avins
Guest
|
| Posted:
Tue Nov 29, 2005 5:16 pm Post subject:
Re: Building a (cheap) software radio |
|
|
Christen Fihl wrote:
| Quote: | Michel: > by the way, what should I get, the three QSD kit, Low Band OSC/BPF
kit and High Band OSC/BPF kit, or is there some that's not necessary?
SoftRock5: > As explained below, the project has two modules: a baseboard
with the sampling, voltage regulator and audio amp ($19); and a daughtercard
providing the band-specific oscillator and filters ($7.50 each of two
modules that cover 80m-30m and 20m-10m, respectively).
LowBand is low frequency, long wire, many meters, ie 80m.
HighBand is 10-20Meter. Needs the shortest antenna.
Pick one or the other band filter, and a baseboard, as far as I can tell.
My own SoftRock4 has no filter, just an oscillator on 7MHz (40Meter only).
|
These are Amateur bands. You should get a lot of conversation. I lost
interest in amateur radio when I found that most of what people talked
about was the equipment they used to do the talking. I built some
equipment for a few friends. To me, that was more interesting.
Jerry
--
Engineering is the art of making what you want from things you can get.
ŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻ |
|
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|
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Jerry Avins
Guest
|
| Posted:
Tue Nov 29, 2005 5:16 pm Post subject:
Re: Building a (cheap) software radio |
|
|
Michel Rouzic wrote:
| Quote: | Jerry Avins wrote:
Michel Rouzic wrote:
Jerry Avins wrote:
You *said* that you want to input an FM channel to your PC sound system.
None of the links here deal with FM, and all the hardware described
delivers audio.
I didn't even understand that. seems like i ain't gonna get to what i
wanted
Probably not, but you can have something else nifty instead. You need to
understand what's being offered, instead of jumping to conclusions. For
now, I suggest you get a copy of /The Radio Amateur's Handbook/ from the
ARRL. http://www.arrl.org/catalog/?words=handbook What you're looking at
isn't "software radio", but "software defined radio". Big difference!
haha, tell wikipedia : "Software-defined radio
From Wikipedia, the free encyclopedia.
(Redirected from Software radio)"
btw, you said the hardware described above delivers audio, does it
means it's already demodulated?
|
What I see is demodulated to I and Q (in phase and quadrature) at audio.
From there you can process to single sideband, NBFM, and more.
| Quote: | There's probably more satisfaction to be had from understanding how
something works than there is from making it work without knowing the
details. Doing both is really marvelous.
yup, and ill get myself ARRL Handbook, i hope it'll help me
understanding it all better.
|
Good move!
Jerry
--
Engineering is the art of making what you want from things you can get.
ŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻ |
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|
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Michel Rouzic
Guest
|
| Posted:
Tue Nov 29, 2005 5:17 pm Post subject:
Re: Building a (cheap) software radio |
|
|
Jerry Avins wrote:
| Quote: | Michel Rouzic wrote:
Jerry Avins wrote:
You *said* that you want to input an FM channel to your PC sound system.
None of the links here deal with FM, and all the hardware described
delivers audio.
I didn't even understand that. seems like i ain't gonna get to what i
wanted
Probably not, but you can have something else nifty instead. You need to
understand what's being offered, instead of jumping to conclusions. For
now, I suggest you get a copy of /The Radio Amateur's Handbook/ from the
ARRL. http://www.arrl.org/catalog/?words=handbook What you're looking at
isn't "software radio", but "software defined radio". Big difference!
|
haha, tell wikipedia : "Software-defined radio
| Quote: | From Wikipedia, the free encyclopedia.
(Redirected from Software radio)" |
btw, you said the hardware described above delivers audio, does it
means it's already demodulated?
| Quote: | There's probably more satisfaction to be had from understanding how
something works than there is from making it work without knowing the
details. Doing both is really marvelous.
|
yup, and ill get myself ARRL Handbook, i hope it'll help me
understanding it all better. |
|
| Back to top |
|
|
Michel Rouzic
Guest
|
| Posted:
Tue Nov 29, 2005 5:17 pm Post subject:
Re: Building a (cheap) software radio |
|
|
Christen Fihl wrote:
| Quote: | At last someone understood what I wanted to do!
Thanks
You once wrote you wanted something like:
AM, FM, SSB, why not TV too, nothing precise
and you also asked:
.... starting at the end of November." think I should order it?
Depends on how wideband you want, and how high in frequency.
Wideband commercial FM around 100MHz cannot be received with SoftRock.
- Too high a frequency (easy to modify with other components), but still
fixed on xtal frequency or use a DDS.
- Too wide to decode in a normal soundboard, which always can do 44.1KHz
samples (about 20KHz bandwith decoded).
With a 96KHz sampler, you can get 40KHz (Google "soundboard 96KHz" and
find
http://www.natch.co.uk/downloads/SigJenny/usingsjn/Soundboard/Soundboard.html)
Or spend more money on "Creative Sound Blaster Audigy 4 Pro Limited
Edition" 192KHz sampling, I would not try this, as I like cheap too.
|
I'm considering acquiring a BT878 based TV tuner, it's supposed to have
an input of 448 ksps (but from what I understood, due to "aperture
jitter" it still won't do it for wideband FM). Just wondering about one
thing, Jerry Avins said that the softrock delivers audio (I and Q
actually, althought i hardly understand what it means, besides that Q
is the hilbert transformed I, if i got it right) does it means that it
delivers an already demodulated signal?
How high in receiving frequencies can you get with SoftRock? (i think i
saw something about that on the site but it was in meters) and with
SoftRock + DDS?
| Quote: | Wideband FM is out.
Seattle for narrowband, something like 5KHz. That leaves the whole
shortwave area. Do start out on a fixed range like SoftRock, DDS later
maybe.
Besides AM, FM, SSB, you can do TV (slowscan, called SSTV not real TV)
Morse, PSK, RTTY,
PSK is fun. It is narrowband, about 100Hz. Terminal mode with 31baud
data. In a normal voicewidth of 3KHz, you can have many active users
simultaniously. Very easy to see on a waterfall display.
SSTV: See some pictures on http://www.hffax.de/Destination.htm and
http://www.oz6sstv.dk/
See http://www.ncdxf.org/Beacon/bandplan.html for which signals are
normally send on each ham band. 7.040MHz is SSTV etc.
.... starting at the end of November." think I should order it?
For wideband FM, then no!
Anything else on shortwave, sure.
um... with a softrock 5.0 and a DDS, what kind of thing could I do,
and also, what kind of antenna would I need?
Start with fixed frequency SoftRock. You still have many signals to play
with.
For antenna, throw some wire out the windows into a tree, and you got
plenty of signal.
|
cool, i got some 50-meter wire layin in some box, i guess it should do
it. i only wonder how i'ma keep it outside while havin my window
closed. is there a difference in efficiency if u keep a 50-meter cable
straight or if you kind of fold it around? |
|
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|
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Michel Rouzic
Guest
|
| Posted:
Tue Nov 29, 2005 5:17 pm Post subject:
Re: Building a (cheap) software radio |
|
|
Christen Fihl wrote:
<snip>
by the way, what should I get, the three QSD kit, Low Band OSC/BPF kit
and High Band OSC/BPF kit, or is there some that's not necessary? |
|
| Back to top |
|
|
Christen Fihl
Guest
|
| Posted:
Tue Nov 29, 2005 5:17 pm Post subject:
Re: Building a (cheap) software radio |
|
|
| Quote: | I'm considering acquiring a BT878 based TV tuner, it's supposed to have an
input of 448 ksps (but from what I understood, due to "aperture
You need 2 A/D's, to make both I and Q signals!! Makes it comples to use |
BT878 I guess.
The signal from SoftRock is no demodulated yet. That is where the software
sets in.
You get I and Q from the quadrature part of SoftRock.
In analog world: quadrature demodulator:
http://n.ethz.ch/student/rodonil/da/bericht/node52.html
Digital, then you feed I and Q into FFT functions as real and complex parts,
as far as I understand it (not studied much yet). And then do some more
magic ;-)
In SoftRock you get I and Q by opening and closing 4 switches, to get
signales delayed 0, 90, 180 or 270 degree.
A simple wire can pass under a closed wooden window without killing the
signal. Any wire is good for a start. Always straight or big zigzag somehow,
not in a big pile.
A wire is like putting your finger on a screwdriver in the antenna socket on
your radio ;-)
| Quote: | How high in receiving frequencies can you get with SoftRock?
300 divided my meter makes MHz. 40Meter is about 7MHz. |
--
Christen Fihl
http://oz1aab.Fihl.net/ |
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Christen Fihl
Guest
|
| Posted:
Tue Nov 29, 2005 5:17 pm Post subject:
Re: Building a (cheap) software radio |
|
|
Michel: > by the way, what should I get, the three QSD kit, Low Band OSC/BPF
kit and High Band OSC/BPF kit, or is there some that's not necessary?
SoftRock5: > As explained below, the project has two modules: a baseboard
with the sampling, voltage regulator and audio amp ($19); and a daughtercard
providing the band-specific oscillator and filters ($7.50 each of two
modules that cover 80m-30m and 20m-10m, respectively).
LowBand is low frequency, long wire, many meters, ie 80m.
HighBand is 10-20Meter. Needs the shortest antenna.
Pick one or the other band filter, and a baseboard, as far as I can tell.
My own SoftRock4 has no filter, just an oscillator on 7MHz (40Meter only).
--
Christen Fihl
http://oz1aab.Fihl.net/ |
|
| Back to top |
|
|
Michel Rouzic
Guest
|
| Posted:
Tue Nov 29, 2005 11:30 pm Post subject:
Re: Building a (cheap) software radio |
|
|
Christen Fihl wrote:
| Quote: | I'm considering acquiring a BT878 based TV tuner, it's supposed to have an
input of 448 ksps (but from what I understood, due to "aperture
You need 2 A/D's, to make both I and Q signals!! Makes it comples to use
BT878 I guess.
|
Oh, yeah, I think it only inputs mono. So, will my 44.1 ksps sound card
will be enough to do the job anyways?
| Quote: | The signal from SoftRock is no demodulated yet. That is where the software
sets in.
You get I and Q from the quadrature part of SoftRock.
In analog world: quadrature demodulator:
http://n.ethz.ch/student/rodonil/da/bericht/node52.html
Digital, then you feed I and Q into FFT functions as real and complex parts,
as far as I understand it (not studied much yet). And then do some more
magic ;-)
|
Wait, if you feed I and Q into FFT functions as real and complex parts,
it means that I and Q are in the frequency domain?
| Quote: | In SoftRock you get I and Q by opening and closing 4 switches, to get
signales delayed 0, 90, 180 or 270 degree.
A simple wire can pass under a closed wooden window without killing the
signal.
|
The problem is that it won't work with my aluminium window
| Quote: | Any wire is good for a start. Always straight or big zigzag somehow,
not in a big pile.
|
Ok, I guess I'll zigzag my 50 meter cable (it's rigid so it should do
it) and put it somewhere in my bedroom. If I zigzag it flat, I guess
the reception of a station will depend on its orientation right? By the
way, does it work better if you connect your wire to some big metallic
thing like the doors of a closet or a gutter?
| Quote: | A wire is like putting your finger on a screwdriver in the antenna socket on
your radio ;-)
How high in receiving frequencies can you get with SoftRock?
300 divided my meter makes MHz. 40Meter is about 7MHz.
--
Christen Fihl
http://oz1aab.Fihl.net/ |
|
|
| Back to top |
|
|
Michel Rouzic
Guest
|
| Posted:
Tue Nov 29, 2005 11:33 pm Post subject:
Re: Building a (cheap) software radio |
|
|
Christen Fihl wrote:
| Quote: | Michel: > by the way, what should I get, the three QSD kit, Low Band OSC/BPF
kit and High Band OSC/BPF kit, or is there some that's not necessary?
SoftRock5: > As explained below, the project has two modules: a baseboard
with the sampling, voltage regulator and audio amp ($19); and a daughtercard
providing the band-specific oscillator and filters ($7.50 each of two
modules that cover 80m-30m and 20m-10m, respectively).
LowBand is low frequency, long wire, many meters, ie 80m.
HighBand is 10-20Meter. Needs the shortest antenna.
Pick one or the other band filter, and a baseboard, as far as I can tell.
My own SoftRock4 has no filter, just an oscillator on 7MHz (40Meter only).
|
umm... does it mean that a softrock with a lowband kit will only
receive signals between 3.75 and 10 Mhz, or does it work differently (i
guess you can receive other stuff than 7 MHz signals right?). And what
will the DDS-60 change to it? |
|
| Back to top |
|
|
Michel Rouzic
Guest
|
| Posted:
Tue Nov 29, 2005 11:35 pm Post subject:
Re: Building a (cheap) software radio |
|
|
Jerry Avins wrote:
| Quote: | Christen Fihl wrote:
Michel: > by the way, what should I get, the three QSD kit, Low Band OSC/BPF
kit and High Band OSC/BPF kit, or is there some that's not necessary?
SoftRock5: > As explained below, the project has two modules: a baseboard
with the sampling, voltage regulator and audio amp ($19); and a daughtercard
providing the band-specific oscillator and filters ($7.50 each of two
modules that cover 80m-30m and 20m-10m, respectively).
LowBand is low frequency, long wire, many meters, ie 80m.
HighBand is 10-20Meter. Needs the shortest antenna.
Pick one or the other band filter, and a baseboard, as far as I can tell.
My own SoftRock4 has no filter, just an oscillator on 7MHz (40Meter only).
These are Amateur bands. You should get a lot of conversation. I lost
interest in amateur radio when I found that most of what people talked
about was the equipment they used to do the talking. I built some
equipment for a few friends. To me, that was more interesting.
|
hearing that is almost turning down. i hope it'll be more fun than to
listen people chatting about which equipement they use :-) |
|
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