Record the entire RF spectrum

GNU Radio
1

Hi there everyone,

I sent Eric and email asking if it was possible to record the entire
spectrum and about the possibilities that would result if this was
possible. After an excellent reply, I continued and he suggested I post
here for more information. I would be very interested in the answers.
Here’s what I wrote:

If it is possible, and also assuming enough storage-space is available
doesn’t sound a bad price for the necessary equipment. How accessible is
the project? I mean, I develop software for a living but not mega
low-level stuff. Is it a requirement to understand fully electronics?

Sorry for going on too much.

Thanks for your excellent reply,

Mat

2

On Wed, 2006-08-30 at 09:24 +0100, mat holton wrote:

Hi there everyone,

I sent Eric and email asking if it was possible to record the entire
spectrum and about the possibilities that would result if this was
possible. After an excellent reply, I continued and he suggested I post
here for more information. I would be very interested in the answers.

That is what got me excited - in short, you can record an 8Mhz wide
band with the USB bus (minimum decimation of 64Mhz sample rate is 8).
That’s one TV channel or 1/3 of the FM band. However it eats up disk
space pretty quick at that rate, about 50Gb every 15 minutes.
I use smaller pre-demodulation recording for practical ham and shortwave
listening - setup a good listening post to capture 640KHz (decim = 100)
of an ‘event’ (contests, sunspots, etc) then go dx’ing over and over
again ;). 6900 - 7500 KHz is one of my favorite bands, where you can get
pirates, hams, international broadcasters, utilities, spy numbers, a
time station, etc., and only uses about 20Gb/hour.

–Chuck

3

Hi all,

I’ve modified the fpga design to include some gadgets
like a signal generator, qpsk modulator, etc…

My signal generator is sitting just in between the TX
buffer and the Interpolator (tryed after the
interpolator also). There is a software controlable
switch (FR_USER_3) to turn on/off the generator and
restore the regular TX-Chain Path.

Now, may be its obvious but I cant seem to find the
answer:

My signal generator only works if I have some signal
comming in from the regular tx-path (Tx-buffer). I
know its probably related to some strobe or enable
or… Or perhaps it depends on the Microcontroller
???

Any clues???

Thank you

Angilberto.

Do You Yahoo!?
Tired of spam? Yahoo! Mail has the best spam protection around

4

At 06:18 AM 8/30/2006, you wrote:

band with the USB bus (minimum decimation of 64Mhz sample rate is 8).
That’s one TV channel or 1/3 of the FM band. However it eats up disk
space pretty quick at that rate, about 50Gb every 15 minutes.
I use smaller pre-demodulation recording for practical ham and shortwave
listening - setup a good listening post to capture 640KHz (decim = 100)
of an ‘event’ (contests, sunspots, etc) then go dx’ing over and over
again ;). 6900 - 7500 KHz is one of my favorite bands, where you can get
pirates, hams, international broadcasters, utilities, spy numbers, a
time station, etc., and only uses about 20Gb/hour.

I tried using video tape in the late 80s as a poor man’s wideband analog
data recorder with some success. I wonder if the newer generation of
D-VHS
can be adapted to do more general digital data recording?

Steve