Do you recognize this sound?

It may sound like static to the uneducated, but some of us will recognize the signal from the mother ship that the time has come!

A jammer, perhaps???

Drew

It sounds close to white noise to me.

was that the famous Russian "woodpecker"... the wideband over the horizon radar that cause so much interference on the bands for so long?

characterize

This wave file is from the Bowles tape of the Dictabelt recorded by the Dallas Police Department about one minute before the assassination of President Kennedy.

Herbert

an inadvertent key down during a special event is a pretty run of the mill occurrence.

it happens more often when you bring out the reserves and equip them with the dregs from the storage room.

could be anything from a sticky mic switch to someone sitting on the mic.

Nearly nothing about the JFK case is run of the mill. For example consider what the critics of the acoustic evidence had to say.

Herbert

OK.

Then WHO killed JFK?

EMWTK

| I have a wave file from a radio reception made four decades ago. | | ftp://

| | The sound is familiar to me and wonder how others would characterize | this signal?

Here's one I found. See if you can tell what the sound is from, as opposed to what the sound is.

A kazoo?

On Tue, 10 May 2005 15:10:53 GMT ehsjr wrote: | snipped-for-privacy@ipal.net wrote: |> On 4 May 2005 14:58:08 -0700 Herbert Blenner wrote: |> |> | I have a wave file from a radio reception made four decades ago. |> | |> | ftp://

|> | |> | The sound is familiar to me and wonder how others would characterize |> | this signal? |> |> Here's one I found. See if you can tell what the sound is from, as |> opposed to what the sound is. |> |> |> | | A kazoo?

Nope. Hint: the device is electrically powered.

i beleive this statement, without further qualification, is innaccurate.

"Since keying on of a second transmitter decreases the received audio of the first, this renders attack characteristics of AGC as inconclusive evidence, especially when magnitudes of the decreases are unreported."

the statement should address the relative signal strengths of the 2 (or more) signals

this sentance makes no sense to me

"In a FM system as used by the DPD, cross talk modulates the frequency of the transmitter."

transmitters are modulated by audio, not cross-talk.

the next sentance is poorly worded and thus difficult to make sense of.

When another station transmits concurrently and creates a heterodyne, its frequencies shift in accordance with changes in loudness of the cross talk at the transmitter

what frequencies shift? audio? RF? the phrase "cross talk at the transmitter" has no apparent meaning... please define it.

the phrase "by-radio nature" has no commonly accepted meaning in radio communications.

"Although the Committee on Ballistic Acoustics should have tested heterodynes for frequency modulation as conclusive evidence of the by-radio nature of the cross talk, they pursued fallacious arguments"

you cannot test an unmodulated carrier for frequency modulation. perhaps you can gaive a probabal determiantion the the recorded audio was de-moduladed by a FM receiver section.

Hubert, i know my writing style is a little curt, but im not intending to "flame". im just pointing to what seem to me to be errors.

Tim

recorded by

assassination

innaccurate.

The strengths of the radio signals at the receiver are unknown.

frequency of

See my next response.

Cross-talk arises when a transmitter operates within an earshot of a blaring receiver on another channel. Now the cross-talk at the transmitter modulates the frequency of the RF. When another station transmits the frequency of the heterodyne would not be constant. Instead the interaction of the two carriers produce a frequency modulated heterodyne.

"By-radio nature" is a vague and inaccurate term to describe nonlinear processes that produce an interaction between signals. Corresponding they use the term "by-audio nature" to describe linear operations that produce no interaction between the signals.

The brief burst of noise at the end of a solo transmission shows squelch action. This is evidence of reception by a FM receiver. A simultaneous transmission of unmodulated carriers of nearly the same strength produces a heterodyne with prominent second harmonic. This harmonic provides strong evidence of reception by a FM receiver. A frequency modulated heterodyne arising from a simultaneous transmission of at least one modulated carrier is the strongest evidence of reception by a FM receiver.

Herbert

intending to

Is that one of those things where they program an old computer to make music by running a program and listening to the interference produced in an AM radio near it?

On Thu, 12 May 2005 19:25:57 +0000 (UTC) Michael Moroney wrote: | snipped-for-privacy@ipal.net writes: | |>Here's one I found. See if you can tell what the sound is from, as |>opposed to what the sound is. | |>

| | Is that one of those things where they program an old computer to make | music by running a program and listening to the interference produced | in an AM radio near it?

Not quit. In this case it is an IBM model 1403 line printer printing an output with a pattern of characters designed to control the impact timing on each of the 132 print hammers as the character chain runs around in circles.

the univac I used a program for diagnostics, it was called 'blue tango'. it was a bunch of algorithms that played the tune through an audio amplifier attached to the junction of the arithmetics. it sounded very mechanical but it was a big help to know that thwe system was ok.

also, at GE computer, we used a diagnostic program and an AM radio to listen to the generated noise. we would rap on the PC board backs and, if the machine stopped, we knew where there was a loose connection on that card. this was when discrete components were used. ICs still hadn't happened. sammmmm