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N1EE February 8th 04 07:50 AM

Marine Radio RF Ground Question
 
What elements make a good Radio Frequency
(RF) ground system in a yacht?

Bart Senior

Gay Sailor February 8th 04 03:25 PM

Marine Radio RF Ground Question
 
A counterpoise.



"N1EE" wrote in message
om...
What elements make a good Radio Frequency
(RF) ground system in a yacht?

Bart Senior




Nav February 9th 04 01:24 AM

Marine Radio RF Ground Question
 
Mostly, hydrogen, oxygen, sodium, chorine and copper. In the right
proportions and places of course.

Cheers

N1EE wrote:

What elements make a good Radio Frequency
(RF) ground system in a yacht?

Bart Senior



N1EE February 10th 04 01:58 AM

Marine Radio RF Ground Question
 
What is the best way to make a counterpoise for
a boat?

"Gay Sailor" wrote

A counterpoise.



"N1EE" wrote


What elements make a good Radio Frequency
(RF) ground system in a yacht?


Gay Sailor February 10th 04 02:57 AM

Marine Radio RF Ground Question
 
The simplest is a variable series LC circuit that tunes the ground path for
the lowest impedance possible.
A caveat though, the voltage across either element is the circuit Q times
the applied voltage. If you drive a 12volt Vcc amplifier (voltage swing of
24 volts) into a circuit with a Q of 10, there is 240 volts across the
series inductor and 240 volts across the series capacitor. So for your 12
volt output driver one would be wise to use 500 volt capacitors and
inductors.

Why not just convert your backstay antenna into a sleeve dipole? No ground
is necessary for this antenna, the radiation pattern is good and the
bandwidth is ok. I ran some NEC simulations on a 35 foot sleeve dipole over
a seawater ground and found the patterns and SWR to be quite good. If I get
a round to it I'll post the plans for such an antenna on a website. Any
engineer worth the title can look up a sleeve dipole on the net and figure
out how to build one too.

Swishy tither boy gay sailor!


"N1EE" wrote in message
m...
What is the best way to make a counterpoise for
a boat?

"Gay Sailor" wrote

A counterpoise.



"N1EE" wrote


What elements make a good Radio Frequency
(RF) ground system in a yacht?




Gay Sailor February 10th 04 03:42 AM

Marine Radio RF Ground Question
 
http://www.arising.com.au/people/Hol...ph/counter.htm



"N1EE" wrote in message
om...
What elements make a good Radio Frequency
(RF) ground system in a yacht?

Bart Senior




Jonathan Ganz February 10th 04 04:24 AM

Marine Radio RF Ground Question
 
Gilligan, you're way too nerdy for most of these people...

"Gay Sailor" wrote in message
link.net...
The simplest is a variable series LC circuit that tunes the ground path

for
the lowest impedance possible.
A caveat though, the voltage across either element is the circuit Q times
the applied voltage. If you drive a 12volt Vcc amplifier (voltage swing

of
24 volts) into a circuit with a Q of 10, there is 240 volts across the
series inductor and 240 volts across the series capacitor. So for your 12
volt output driver one would be wise to use 500 volt capacitors and
inductors.

Why not just convert your backstay antenna into a sleeve dipole? No ground
is necessary for this antenna, the radiation pattern is good and the
bandwidth is ok. I ran some NEC simulations on a 35 foot sleeve dipole

over
a seawater ground and found the patterns and SWR to be quite good. If I

get
a round to it I'll post the plans for such an antenna on a website. Any
engineer worth the title can look up a sleeve dipole on the net and figure
out how to build one too.

Swishy tither boy gay sailor!


"N1EE" wrote in message
m...
What is the best way to make a counterpoise for
a boat?

"Gay Sailor" wrote

A counterpoise.



"N1EE" wrote


What elements make a good Radio Frequency
(RF) ground system in a yacht?






Nav February 10th 04 06:24 AM

Marine Radio RF Ground Question
 
That would be interesting, please do it.

Cheers
Gay Sailor wrote:

The simplest is a variable series LC circuit that tunes the ground path for
the lowest impedance possible.
A caveat though, the voltage across either element is the circuit Q times
the applied voltage. If you drive a 12volt Vcc amplifier (voltage swing of
24 volts) into a circuit with a Q of 10, there is 240 volts across the
series inductor and 240 volts across the series capacitor. So for your 12
volt output driver one would be wise to use 500 volt capacitors and
inductors.

Why not just convert your backstay antenna into a sleeve dipole? No ground
is necessary for this antenna, the radiation pattern is good and the
bandwidth is ok. I ran some NEC simulations on a 35 foot sleeve dipole over
a seawater ground and found the patterns and SWR to be quite good. If I get
a round to it I'll post the plans for such an antenna on a website. Any
engineer worth the title can look up a sleeve dipole on the net and figure
out how to build one too.

Swishy tither boy gay sailor!


"N1EE" wrote in message
m...

What is the best way to make a counterpoise for
a boat?

"Gay Sailor" wrote


A counterpoise.


"N1EE" wrote


What elements make a good Radio Frequency
(RF) ground system in a yacht?






Nav February 10th 04 06:40 AM

Marine Radio RF Ground Question
 


Gay Sailor wrote:

A caveat though, the voltage across either element is the circuit Q times
the applied voltage. If you drive a 12volt Vcc amplifier (voltage swing of
24 volts) into a circuit with a Q of 10, there is 240 volts across the
series inductor and 240 volts across the series capacitor. So for your 12
volt output driver one would be wise to use 500 volt capacitors and
inductors.


Can you explain this. I though that for a parallel LC the impedence went
to infinite at resonance (f=1/2pi sqrt(LC)) so that Vin=Vout.

What am I missing?

Cheers


Wally February 10th 04 02:48 PM

Marine Radio RF Ground Question
 
Nav wrote:

Can you explain this. I though that for a parallel LC the impedence
went to infinite at resonance (f=1/2pi sqrt(LC)) so that Vin=Vout.

What am I missing?


Getting beyond my knowledge (or memory), but Gilly did say that the LC
circut is series - would that work better?


--
Wally
www.artbywally.com
www.wally.myby.co.uk/music





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