Record the entire RF spectrum

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

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

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.


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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