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Ed March 9th 07 07:03 PM

mobile antenna ground loss
 
You've gotten several suggestions. 6-8 Ohms is no better than 10-12
Ohms as a guess; however, just what does this program do that this
number is so important in performing what it does?


mobile.exe is a little DOS based program that gives you radiation
efficiency, Q factor, etc, after you input several proposed design
measurements of a mobile antenna. When calculating these antenna
parameters for a "fixed station" type of mounting, ( not on a vehicle, I
guess), ground loss is one figure required for input. It is NOT a
required input when figuring for mounting on a vehicle, I just realized.


Ed

Cecil Moore March 9th 07 07:08 PM

mobile antenna ground loss
 
Ed wrote:
It is NOT a
required input when figuring for mounting on a vehicle, I just realized.


Does it require one to input the type of vehicle?
--
73, Cecil http://www.w5dxp.com

Ed March 9th 07 07:11 PM

mobile antenna ground loss
 
(Richard Harrison) wrote in news:12998-
:

Ed wrote:
"Wouldn`t you think that losses might be less on a large vehicle like

an
RV or Truck,---."

I earlier rederred to an article by W1DBM in QST and an ARRL Antenna
Anthology from the 1970`s. The title was: "Antennas for Trailers and
Campers".

Everything old is new again. Please see the article: "Compact 40 Meter
Loop for Your Recreational Vehicle" by W6NBC on page 41 of the March
2007 QST.

Best regards, Richard Harrison, KB5WZI




I saw that. Neat idea, but as previously mentioned, I think, my
needed antenna design is for 80M, operation only while stopped, must be
vertical, and lastly, must not require me to climb up to the RV rooftop
to put it up or take it down. I have a good idea where I'm going with
this and will discuss the final product when it is completed ... probably
several weeks from now.



Ed




Ed

Ed March 9th 07 07:13 PM

mobile antenna ground loss
 
Cecil Moore wrote in news:u%gIh.9028$jx3.5787
@newssvr25.news.prodigy.net:

Richard Harrison wrote:
Everything old is new again.


In one of the CA 75m shootouts, the strongest signal by far
was from a large RV with a motor-erected vertical on top.
Of course, it violated the 12.5 foot height-above-ground
limit for official entries. Heck, the top of the RV was
almost 12.5 foot above ground.
--
73, Cecil, w5dxp.com



A beautifully constructed 23' marine antenna on the roof with custom
fabricated lift mechanism, I believe? I think I saw that rig at Quartzite
in January. Fantastic.


Ed

Ed March 9th 07 07:32 PM

mobile antenna ground loss
 
Cecil Moore wrote in news:ahiIh.6363$M65.6276
@newssvr21.news.prodigy.net:

Ed wrote:
It is NOT a
required input when figuring for mounting on a vehicle, I just

realized.

Does it require one to input the type of vehicle?



yes, input selections are pretty much based on vehicle size; largest
vehicle choice is a Van type. Last choice is "fixed station" which I
assume means no vehicle at all.. and that is the only choice requiring a
ground loss entry. Since my proposed antenna is for an RV, it appears I
really needn't have asked the ground loss question at all!

mobile.exe is a rather neat little DOS program located on the CD in
the back of newer ARRL antenna books, I believe.... maybe in the Handbook
too, I'm not sure on that.


Ed





Cecil Moore March 9th 07 08:14 PM

mobile antenna ground loss
 
Ed wrote:
... as previously mentioned, I think, my
needed antenna design is for 80M, operation only while stopped, must be
vertical, and lastly, must not require me to climb up to the RV rooftop
to put it up or take it down. I have a good idea where I'm going with
this and will discuss the final product when it is completed ... probably
several weeks from now.


At one of the CA 75m shootouts, Sanford, W6YY had
a motorized 30 foot vertical mounted on top of his
huge RV. While he was traveling, it laid down against
the top of the RV. When he was stopped, he had it
motorized so he could raise it to a vertical position.
He beat the best of the best 75m mobile bugcatchers
and screwdrivers by 2 dB and beat a 75m hamstick
by about 14 dB. It's certainly worth considering.
--
73, Cecil http://www.w5dxp.com

Richard Clark March 10th 07 03:04 AM

mobile antenna ground loss
 
On 09 Mar 2007 19:32:20 GMT, Ed
wrote:

mobile.exe is a rather neat little DOS program located on the CD in
the back of newer ARRL antenna books, I believe.... maybe in the Handbook
too, I'm not sure on that.


Hi Ed,

Doesn't sound worth the clock cycles to run it when a Magic 8-Ball
would be just as accurate.

You can get better results from the free version of EZNEC because you
know what you've put in and what relationship it has to the whole. If
you belly up to the bar and buy the full-blown version, then you can
design a model of your antenna, RV, ladder and frame.

73's
Richard Clark, KB7QHC

Ed March 10th 07 05:05 AM

mobile antenna ground loss
 
Richard Clark wrote in
:

On 09 Mar 2007 19:32:20 GMT, Ed
wrote:

mobile.exe is a rather neat little DOS program located on the CD in
the back of newer ARRL antenna books, I believe.... maybe in the
Handbook too, I'm not sure on that.


Hi Ed,

Doesn't sound worth the clock cycles to run it when a Magic 8-Ball
would be just as accurate.

You can get better results from the free version of EZNEC because you
know what you've put in and what relationship it has to the whole. If
you belly up to the bar and buy the full-blown version, then you can
design a model of your antenna, RV, ladder and frame.

73's
Richard Clark, KB7QHC



Didn't realize there was a free version. I had been thinking of biting
the bullet and buying it, but wasn't sure if I would like the program. A
freebie access to it will allow me to decide.

. . . off to download....



Ed


Richard Clark March 10th 07 05:54 AM

mobile antenna ground loss
 
On 10 Mar 2007 05:05:30 GMT, Ed
wrote:

. . . off to download....


Hi Ed,

You are about to discover there are more questions than answers...

That's what keeps it interesting.

73's
Richard Clark, KB7QHC


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