Re: LF: Re: Band is open to VK!

["Fausto Coletti" <faustocoletti@alice.it>]

Hi Marcus,

 

I understand that it is hard to believe as the means at his disposal could have received that signal in 1901,

but a year later he repeated the experiment with the same devices, perhaps a little optimized but not very

different, this time with several witnesses.

 

The sound of a spark gap transmitter received with a mercury Coherer on a earphone is a buzz, as the sound of a diode detector.

However a metal powder Coherer It is not suitable to receive sounds in a headset, he begins to conduct

when crossed by an electromagnetic field and continues to conduct until you give him a hit.

For this reason it was used with a Morse tape machine and in series with the circuit there was an electromagnet

with a little hammer that was used to strike the Coherer each character received.

 

I am currently collaborating with the Guglielmo Marconi Foundation to repeat some experiments from the first

transmission of 1895 with the replica of original equipment, trying to measure what was actually the energy

radiated by a spark gap transmitter and, what could be the effective sensitivity of the detectors available

at the end of the 19th century.

 

73, Fausto

 

 

 

 

 

 

----- Original Message -----

From: Markus Vester

To: rsgb_lf_group@blacksheep.org

Sent: Saturday, August 22, 2015 8:02 PM

Subject: Re: LF: Re: Band is open to VK!

Hi Fausto,

 

don't get me wrong - I'm in no way opposed to, or trying to diminish Marconi's work, which was indeed revolutionary at his time. I just find it hard to believe that he actually received the famous three dots on MF at the time in 1901.

 

Thanks for the link to the TV documentary. Around minute 28, the soundtrack lets us hear a real WOW signal, beautiful and convincing triple knocks. But would the sound of a coherer really have been like that?

 

Fortunately Edgar's LF receiver in Tasmania seems is not much hampered by man made QRM, his nighttime noise floor seems to be dominated primarily by natural static background.

 

All the best,

Markus 

 

 

From: Fausto Coletti

Sent: Saturday, August 22, 2015 7:11 PM

To: rsgb_lf_group@blacksheep.org

Subject: Re: LF: Re: Band is open to VK!

I know these documents and I know also how many detractors there have been and there are against the work of Guglielmo Marconi.

Now I'm not here to say if in December 1901 Marconi succeeded or not in his attempt, I'm convinced of it, the fact is that a year later

he successfully repeated the experiment with the same equipment, in front of numerous witnesses and people sent by his opponents.

On this there is no doubt.

As there is no doubt that all those who were opposed to Marconi claiming to be able to transmit a telegraphic signal before him,

when Marconi transmitted and receive to two or three hundred kilometers away, they were unable to to receive a signal to a hundred meters.

Here a documentary made by a German broadcaster few years ago:

 

http://www.zdf.de/ZDFmediathek/beitrag/video/1211142/Das-unsichtbare-Netz#/beitrag/video/1211142/Das-unsichtbare-Netz 

 

This is one of the best documentaries I have ever seen and probably the closest to historical truth.

 

@ Stefan DK7FC

 

It is true that in 1901 there was the noise created by the man who today is present but, the noise generated by Mother Nature was also at that time.

Now I do not know what could be the relationship between the sensitivity of Marconi receiver in the 1901 environment, and a modern receiver with the noise of today.

I recently tested some nickel powder Coherer for a historical events which we are organizing for next month and I assure you that a carpenter's tack is more sensitive :-)

 

73, Fausto

 

 

 

 

 

 

 

----- Original Message -----

From: Markus Vester

To: rsgb_lf_group@blacksheep.org

Sent: Saturday, August 22, 2015 6:07 PM

Subject: Re: LF: Re: Band is open to VK!

Hi Fausto, LF,

 

>> do not forget that in 1901 Guglielmo Marconi received a signal across the Atlantic at a frequency around 500 kHz

 

...did he really? I think there is some doubt around this story. With a coherer, it would be very hard to prove the difference between receiving a signal consisting of just three dots, and false triggering by random statics. Considering a situation where a success was badly needed, the reception may well have been the result of wishful thinking.

 

http://www.antiquewireless.org/uploads/1/6/1/2/16129770/45-did_marconi_receive_transatlantic_radio_signals_in_1901.pdf

http://www.antiquewireless.org/uploads/1/6/1/2/16129770/46-did_marconi_receive_transatlantic_radio_signals_in_1901.pdf

 

Today we'd simply say "show us the screenshot" ;-)

 

Best 73,

Markus

 

From: Fausto Coletti

Sent: Friday, August 21, 2015 9:59 PM

To: rsgb_lf_group@blacksheep.org

Subject: Re: LF: Re: Band is open to VK!

:-)) I have a 8 motor drone but can fly only 20 minutes with one Kg payload.

A kite or baloon is better.

Seriously speaking, the difficulties are very big, as rightly says Stefan 160 meters band, has a very different behavior but, do not forget that in 1901 Guglielmo Marconi received a signal across the Atlantic at a frequency around 500 kHz and with a receiver that in comparison with those of today was a tack. Ok were "only" 3500 Km.

Today what are we doing more with our ultramodern equipment?

Today we have SDR, filters, DSP, noise reducer, Marconi at Signal Hill had a drop of mercury.

Today obtain a considerable power is relatively easy and inexpensive,

114 years ago there were only Ruhmkorff coils then, how much power was actually radiated

no one ever taken the trouble to measure it.

But as they did then my compatriot to get those great results: trying, trying and trying again trying to improve something every day.

The important thing is to think that nothing is impossible, maybe improbable but not impossible.

Tonight I bored with the history of telegraphy...:-)

 

73, Fausto IK4NMF

...

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Controllato da AVG - www.avg.com
Versione: 2015.0.6125 / Database dei virus: 4392/10484 - Data di rilascio: 22/08/2015