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Hi Mauro,
Marconi's transmitter in Podhu was a spark gap tx
but at Signal Hill in Canada he had use the sintonic receiver
as your patent number 7777.
73, Fausto IK4NMF
----- Original Message -----
Sent: Saturday, August 22, 2015 7:14
PM
Subject: Re: LF: Re: Band is open to
VK!
the Marconi's trasmitter was a spark tx, with many
harmonics and no selective filters ..
It possible what the
transatlantic contact was made using the 3° or higher harmonic ???
73
de Mauro IK1WVQ
At 18:07 22/08/2015, Markus Vester wrote:
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: [email protected]
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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