Reply
 
LinkBack Thread Tools Search this Thread Display Modes
  #1   Report Post  
Old April 17th 12, 02:18 AM posted to rec.radio.amateur.antenna
external usenet poster
 
First recorded activity by RadioBanter: Jul 2006
Posts: 464
Default The earth

In article , NM5K wrote:

Yep.. I think the frustration tends to be difficulty in understanding
that it's just one type of system, and others that do not require any
ground connection do exist.


Which means you would have to classify his statement as incorrect in
the overall larger picture. I believe most have already stated that
while some antennas do require such a connection, any "complete"
antenna does not require one.


Correct.

One interesting counter-example, would be the simple one of a
full-wavelength loop of wire, which is fed with a balanced feedline
(twinlead or open-wire or ladder line), which is fed from a
fully-balanced transmitter output stage (e.g. with transformer
coupling from the driver transistors). To be extreme about it, let's
say that the transmitter is itself based on a fully-balanced
(differential) circuit, all the way back to the crystal oscillator.
It's powered by a single battery, and is installed in a plastic chassic.

This sort of antenna would have no galvanic connection to "earth" at
all. Measure the resistance or RF impedance between any part of the
antenna or feedline structure, and *anything* not part of the antenna,
and the result will be "huge".

Since it's a loop antenna, it has no "ends"... no points at which
electrons could "fly off". The net current flow going up the feedline
to the antenna will be zero, at all points - a positive current on one
side of the feedline will be exactly balanced by a negative current on
the other side of the feedline. There are no "excess" electrons or
charge flowing in either direction.

You can even insulate the antenna wires, if you wish.

It will transmit just fine, with no connection at all to "ground".
Disconnect the transmitter, install a receiver of a similar "balanced
and isolated" design, and it'll receive just as well... again, with no
connection to "ground".

--
Dave Platt AE6EO
Friends of Jade Warrior home page: http://www.radagast.org/jade-warrior
I do _not_ wish to receive unsolicited commercial email, and I will
boycott any company which has the gall to send me such ads!
  #2   Report Post  
Old April 17th 12, 09:17 AM posted to rec.radio.amateur.antenna
external usenet poster
 
First recorded activity by RadioBanter: Oct 2009
Posts: 707
Default The earth


"Dave Platt" napisa³ w wiadomo¶ci
...

Since it's a loop antenna, it has no "ends"... no points at which
electrons could "fly off".


A loop antena have the antinodes. The points at which electrons could "fly
off".

See Fig. 2: http://www.antiquewireless.org/otb/lodge1102.htm

The net current flow going up the feedline
to the antenna will be zero, at all points - a positive current on one
side of the feedline will be exactly balanced by a negative current on
the other side of the feedline. There are no "excess" electrons or
charge flowing in either direction.


""A further feature of the structure of negative coronas is that as the
electrons drift outwards, they encounter neutral molecules and,
withelectronegative molecules (such as oxygen and water vapor), combine to
produce negative ions. These negative ions are then attracted to the
positive uncurved electrode, completing the 'circuit'.". From: Negative
coronas. Mechanism.
http://en.wikipedia.org/wiki/Corona_...gative_coronas

In the each antenna is the excess/deficit of electrons and "charge flowing
in either direction."
But the negative corona and the positive corona are not simmetrical.
At transmitting you have the deficit and at receiving the excess.
Without the earth the static build up and radio stop working.

You can even insulate the antenna wires, if you wish.


Can you measure the static electricity?

It will transmit just fine, with no connection at all to "ground".
Disconnect the transmitter, install a receiver of a similar "balanced
and isolated" design, and it'll receive just as well... again, with no
connection to "ground".


You will transmit just fine if you have the ground/chassis/counterpoise.
S*


  #3   Report Post  
Old April 17th 12, 09:24 AM posted to rec.radio.amateur.antenna
external usenet poster
 
First recorded activity by RadioBanter: Dec 2008
Posts: 375
Default The earth

Szczepan Bialek wrote:
At transmitting you have the deficit and at receiving the excess.
Without the earth the static build up and radio stop working.


How would you know that when you don't even have a transmitter?

You will transmit just fine if you have the ground/chassis/counterpoise.
S*


And without it, fine as well.
  #4   Report Post  
Old April 17th 12, 04:47 PM posted to rec.radio.amateur.antenna
external usenet poster
 
First recorded activity by RadioBanter: Oct 2009
Posts: 707
Default The earth


"Rob" napisal w wiadomosci
...
Szczepan Bialek wrote:
At transmitting you have the deficit and at receiving the excess.
Without the earth the static build up and radio stop working.


How would you know that when you don't even have a transmitter?


But my "friend" Marconi had a lot. He wrote:
"but in my opinion no practical system of wireless telegraphy
exists
where the instruments are not connected to earth."

You will transmit just fine if you have the ground/chassis/counterpoise.
S*


And without it, fine as well.


It is not true. You know that.
S*


  #5   Report Post  
Old April 17th 12, 05:50 PM posted to rec.radio.amateur.antenna
external usenet poster
 
First recorded activity by RadioBanter: Apr 2012
Posts: 165
Default The earth


"Szczepan Bialek" wrote in message
...

"Rob" napisal w wiadomosci
...
Szczepan Bialek wrote:
At transmitting you have the deficit and at receiving the excess.
Without the earth the static build up and radio stop working.


How would you know that when you don't even have a transmitter?


But my "friend" Marconi had a lot. He wrote:
"but in my opinion no practical system of wireless telegraphy
exists
where the instruments are not connected to earth."

You will transmit just fine if you have the ground/chassis/counterpoise.
S*


And without it, fine as well.


It is not true. You know that.
S*


Hello chaps.
Several of you have said that Szczepan seems unable to accept new ideas.

I see that he persists in believing Marconi's comment that an earth
connection is necessary. Those of us who use Yagi , loop or dipole aerials
know, through experience, that an earth connection is not necessary.
I am undecided why he prefers to believe the opinion of someone who worked
in the early days of radio rather than those of us who use radio in modern
times.

I feel it is awkward to say that Marconi was wrong even though we now know
this is the case. Personally, I'd say that Marconi's opinion that "no
practical system of wireless telegraphy exists where the instruments are not
connected to earth" obviously related to his own use of wireless. As I
understand it, Marconi's aerials were not resonant at the frequency he was
using. They would therefore be a mis-match to his radios and this situation
was alleviated by using connections to earth.

I find it puzzling that Szczepan feels happy to ignore our comments and
continue to accept Marconi's opinion given that he (Szczepan) said that a
transmitter is a "black box" to him. I've speculated that his English may
not be very good but I shall be amused if we find out that his first
language is English despite his non-English name.
He never answered my question about resonant / non-resonant aerials so I
guess his technical knowledge is limited.

Kindest regards to all,
Ian.

ps: If Szczepan is happy to constrain his knowledge to the days of Marconi
then I wonder how come he is using a computer. Didn't have those in the days
of Marconi.










  #6   Report Post  
Old April 17th 12, 06:13 PM posted to rec.radio.amateur.antenna
external usenet poster
 
First recorded activity by RadioBanter: Jun 2006
Posts: 1,898
Default The earth

Ian wrote:


I feel it is awkward to say that Marconi was wrong even though we now know
this is the case. Personally, I'd say that Marconi's opinion that "no
practical system of wireless telegraphy exists where the instruments are not
connected to earth" obviously related to his own use of wireless. As I
understand it, Marconi's aerials were not resonant at the frequency he was
using. They would therefore be a mis-match to his radios and this situation
was alleviated by using connections to earth.


Little of the technology in use today was known in Marconi's time.

Marconi knew nothing of resonance, impedance, or electromagnetic field
theory; it all came after his time.

Marconi would have been totally baffled if shown a helical, slot, yagi,
or any number of antennas invented after his time in common use today.

The only reference antenna Marconi had was a wire of some sort fed against
ground.

For that particular type of antenna, Marconi was correct, but his statement
is NOT correct for antennas in general.



  #7   Report Post  
Old April 17th 12, 06:25 PM posted to rec.radio.amateur.antenna
external usenet poster
 
First recorded activity by RadioBanter: Apr 2012
Posts: 165
Default The earth

wrote in message
...
Ian wrote:


Little of the technology in use today was known in Marconi's time.

Marconi knew nothing of resonance, impedance, or electromagnetic field
theory; it all came after his time.

Marconi would have been totally baffled if shown a helical, slot, yagi,
or any number of antennas invented after his time in common use today.

The only reference antenna Marconi had was a wire of some sort fed against
ground.

For that particular type of antenna, Marconi was correct, but his
statement
is NOT correct for antennas in general.


Hello again.

I bet that Marconi would have been very wiling to learn about new theory and
technology ... unlike some people.

Regards, Ian.


  #8   Report Post  
Old April 17th 12, 05:58 PM posted to rec.radio.amateur.antenna
external usenet poster
 
First recorded activity by RadioBanter: Jun 2006
Posts: 1,898
Default The earth

Szczepan Bialek wrote:

It is not true. You know that.


Marconi was wrong.

Most of the antennas in use today were not invented until after Marconi.

Marconi would be totally baffled if he were shown a helical, yagi or slot
antenna.



  #9   Report Post  
Old April 17th 12, 10:49 PM posted to rec.radio.amateur.antenna
external usenet poster
 
First recorded activity by RadioBanter: Aug 2011
Posts: 76
Default The earth

On 4/17/2012 10:47 AM, Szczepan Bialek wrote:
napisal w wiadomosci
...
Szczepan wrote:
At transmitting you have the deficit and at receiving the excess.
Without the earth the static build up and radio stop working.


How would you know that when you don't even have a transmitter?


But my "friend" Marconi had a lot. He wrote:
"but in my opinion no practical system of wireless telegraphy
exists
where the instruments are not connected to earth."

You will transmit just fine if you have the ground/chassis/counterpoise.
S*


And without it, fine as well.


It is not true. You know that.
S*


I guess all the people I talk to using that portable rig
are just a figment of my imagination?
And likewise here at the house where most of my systems are
ungrounded..
It's actually quite astounding.. I've worked about 29
zillion people using various ungrounded antenna systems that don't work.

How did I pull off such a feat? Did I scream real loud?
Did I hire R. Lee Ermey to scream for me? He's pretty good at it..
Maybe I built a big fire behind the radio, and sent smoke signals..
I suppose that could be a viable explanation, being as that land was
Indian Territory until a couple of years before Marconi made that
statement. :\
I don't own any war drums, so we would have to rule those out.. :|
Maybe I pass notes around the country on the backs of tarantulas..
They usually don't mind as long as I don't use a hat pin to attach
the notes to their backs.
http://home.comcast.net/~disk100/oct17-4.jpg







  #10   Report Post  
Old April 18th 12, 01:39 AM posted to rec.radio.amateur.antenna
external usenet poster
 
First recorded activity by RadioBanter: Jul 2006
Posts: 409
Default The earth



"NM5K" wrote in message ...

On 4/17/2012 10:47 AM, Szczepan Bialek wrote:
napisal w wiadomosci
...
Szczepan wrote:
At transmitting you have the deficit and at receiving the excess.
Without the earth the static build up and radio stop working.


How would you know that when you don't even have a transmitter?


But my "friend" Marconi had a lot. He wrote:
"but in my opinion no practical system of wireless telegraphy
exists
where the instruments are not connected to earth."

You will transmit just fine if you have the ground/chassis/counterpoise.
S*


And without it, fine as well.


It is not true. You know that.
S*


# I guess all the people I talk to using that portable rig
# are just a figment of my imagination?
snip

Nope. Not at all. I have quite a few contacts with a Heathkit HW-7 powered
with 8 "D" cells, a homebrew balanced tuner and open wire dipole. This was
use on board a sailboat.



Reply
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules

Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Earth To GWB! James Douglas Shortwave 1 November 22nd 05 04:29 PM
Earth To GWB! m II Shortwave 0 November 22nd 05 05:47 AM
Earth To GWB! Larry Naumann Shortwave 0 November 21st 05 10:20 PM
CALCULATION OF EARTH RESISTANCE IN MULTI-LAYER EARTH STRUCTURE [email protected] Antenna 2 January 12th 05 03:41 PM
CALCULATION OF EARTH RESISTANCE IN MULTI-LAYER EARTH STRUCTURE [email protected] Equipment 1 January 11th 05 05:14 PM


All times are GMT +1. The time now is 07:15 AM.

Powered by vBulletin® Copyright ©2000 - 2025, Jelsoft Enterprises Ltd.
Copyright ©2004-2025 RadioBanter.
The comments are property of their posters.
 

About Us

"It's about Radio"

 

Copyright © 2017