Thread: The earth
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Old April 11th 12, 10:19 AM posted to rec.radio.amateur.antenna
Geoffrey S. Mendelson Geoffrey S. Mendelson is offline
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First recorded activity by RadioBanter: Jun 2006
Posts: 487
Default The earth

Rob wrote:
Szczepan Bialek wrote:
Not all know that:
""The necessity or utility of the earth connection has been sometimes
questioned, but in my opinion no practical system of wireless telegraphy
exists
where the instruments are not connected to earth."
S*


But it is Marconi's opninion. It is not the truth, it is only an
opinion. When you like, you can say he was "not right". Or you can
just respect that he had this opinion. Your choice.

So we can move on. What is your next question about 1910's scientists?


It may be more accurate than you are giving him credit for. It was based
upon the antenna designs and frequency ranges in use at the time.

All I know is that by the end of WWI, 200 meters was considered to high in
frequency to be useable, which is why the US Navy wanted hams to be limited
to frequencies above it (or wavelengths below it).

The early practical groundless antennas were 1/2 wave, either a dipole
or end fed half wave, and is a 100 meter wire practical? A 1000 meter?

What frequencies (or wavelengths) was he speaking about?

To answer the comment about cell phones, modern ones operate at around
2.1gHz (3G) a frequency that was impossible to produce at the time.

PL-259 connectors are called UHF connectors for a reason, when they were
designed 30mHz was UHF. And that was 30-40 years later.

Geoff.

--
Geoffrey S. Mendelson, N3OWJ/4X1GM/KBUH7245/KBUW5379
In 1969 the US could put a man on the moon, now teenagers just howl at it. :-(