A mobile device uses the user as the counterpoise.
A vehicle is not physically bonded to the earth - yet still works.
A Mag Mount antenna is not physically bonded to the vehicle body - hence it uses a loop radio to antenna antenna to radio and it changes the way the coax interacts with the antenna.
If the radio is bonded to the body and the antenna is bonded to the body the body is capacitive. Turns the whole body into one big counterpoise.

Maybe this is the reason why a 102 inch whip works better then a mag mount antenna or one of those silly dual sticks on a truckers mirrors...

Channel Jumper wrote:

'Rob[_8_ Wrote:
;789340']Szczepan Bialek wrote:-
In 1909 Marconi wrote:
http://tinyurl.com/c3j4ghj

"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."

It is still true?
S*-

I hope you have your GSM phone firmly connected to earth, or it would
operate in violation of Marconi's observations.

A mobile device uses the user as the counterpoise.
A vehicle is not physically bonded to the earth - yet still works.
A Mag Mount antenna is not physically bonded to the vehicle body - hence
it uses a loop radio to antenna antenna to radio and it changes the way
the coax interacts with the antenna.
If the radio is bonded to the body and the antenna is bonded to the body
the body is capacitive. Turns the whole body into one big
counterpoise.

Maybe this is the reason why a 102 inch whip works better then a mag
mount antenna or one of those silly dual sticks on a truckers mirrors...

Balanced antennas such as dipoles do not require a "counterpoise".

http://www.k0bg.com/ground.html

I was saving this for desert.

Read and learn...

On 4/10/2012 10:48 AM, Channel Jumper wrote:
'Rob[_8_ Wrote:
;789340']Szczepan Bialek wrote:-
In 1909 Marconi wrote:
http://tinyurl.com/c3j4ghj

"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."

It is still true?
S*-

I hope you have your GSM phone firmly connected to earth, or it would
operate in violation of Marconi's observations.

A mobile device uses the user as the counterpoise.

Incorrect. The antennas used do not need a counterpoise. In fact the
user is often a hindrance to the antenna working properly.

tom
K0TAR

"Channel Jumper" napisa³ w
wiadomo¶ci ...


A mobile device uses the user as the counterpoise.
A vehicle is not physically bonded to the earth - yet still works.
A Mag Mount antenna is not physically bonded to the vehicle body - hence
it uses a loop radio to antenna antenna to radio and it changes the way
the coax interacts with the antenna.
If the radio is bonded to the body and the antenna is bonded to the body
the body is capacitive. Turns the whole body into one big
counterpoise.

Maybe this is the reason why a 102 inch whip works better then a mag
mount antenna or one of those silly dual sticks on a truckers mirrors...

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*

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?

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. :-(

Geoffrey S. Mendelson wrote:
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.

Which means it is true for specific, limited cases, but not true in general.

There has been a lot learned about electromagnetic theory in the past
100 years that this babbling idiot just ignores.

In article ,
Geoffrey S. Mendelson wrote:

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

My understanding is that in this context, "UHF" is not an acronym for
"ultra-high frequency". It means "Universal High Frequency"... as in,
can be used for all "high frequency" applications.

--
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!

Dave Platt wrote:
In article ,
Geoffrey S. Mendelson wrote:

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

My understanding is that in this context, "UHF" is not an acronym for
"ultra-high frequency". It means "Universal High Frequency"... as in,
can be used for all "high frequency" applications.


Thanks Dave, in all the years I have been interested in radio I never heard
or read that. It does clear up a lot of questions. :-)

73,

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. :-(