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Subject: mobile antenna design performance
Date: 2000/03/24
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Snip
The only real gain is from your wallet. The 102" SS is cheaper than
the other antennas that outperform it.

Well Well Well...... I do believe there Mr. Mystery Man, seeing how
you appear to be trolling for all of my posts and disagreeing with
everyone of them, regardless.... that I'll never be right with you.

I'm an equal opportunity corrector. You needed correction, so you
got it.

Of
course, you didn't ask the question, OR provide any answere, so I'll
let any self displayed ignorance speak for itself.

I believe I have answered the question quite well. At least more
accurately. Perhaps you forgot to read my answer. I will post
it here once again.
*************************************
All things being equal:

1.Top loaded antennas perform marginally better than base loaded

2.Taller antennas (less loading coil) perform better than shorter

3. Thicker antennas perform marginally better than thinner.

4. More conductive antenna stock makes a marginal difference
over less conductive antenna stock.

5. A higher antenna mount works better than a lower mount.

6. A free and clear antenna mount works better than an obstructed one.

7. A more substantial RF ground works better than a minimal ground.

8. A vertical antenna performs better than a diagonal (windblown).

Number 5, 6, & 8 are the most important factors in the performance of
an antenna.


Now if any one could come up with a formula that includes all of
these factors then we would be able to answer your question. There
is no formula. However we can say this.
The best mobile antenna is a thick stiff nine foot whip that is
silver coated and mounted on top of the roof with multiple radial
grounding points.
No one is going to use the antenna above in the real word, so one
might draw the conclusion that in the real world we might substitute a
102" stainless whip for the best real world performance. WRONG.
The 102" is made of stainless. Stainless has only 3% the
conductivity of copper. This alone will stop the 102" stainless from
being the top performer. Subtract also the fact that the 102"
stainless bends over in the wind and is also a relatively thin
antenna.
So what is the best choice? It appears that for a realistic
antenna, it is a mildly loaded top or center loaded antenna made
of thick conductive materials. There are a few of these ugly looking
antennas around. They do work marginally better than the
102" stainless and have the benefit of being shorter. These
antennas can get as short as five foot and still equal or
outperform the 102" stainless.

Percent conductivity of materials, based on copper being the standard
of 100%

Aluminum 65%
Brass 28%
Chrome 74%
Gold 71%
Iron 17%
Silver 106%
Steel 10%
Stainless 3%
**************************************
If, and I repeat, *IF* you did any reading (and paying attention)
before you spewed, You might get something right. Why don't you go
back and read my reply and look at the gain I claimed for a 102"
(that's a quarter wave on the 11 mtr band) whip before you TRY to
correct me? THEN...

That is not what you claimed. I will quote you.........

"At the risk of getting flamed (who am I kidding, it's inevitable),
the best *overall* antenna is the 102" SS whip."

Does not the SS stand for stainless steel? If you are NOW saying that
a 102" whip can outperform a loaded antenna then I will agree. But
you were referring to something else.


you can come back and TRY to give a reply to the
question raised in the post.

I believe that I have done that.

I don't think that the poster asked for ANY of what you offered.
(which was NOTHING btw)

I think most readers of these posts would prefer accuracy. Therefore
corrections should be made when someone is in error.


Signed... Mr. Mystery Man, formally known as tnom

wrote:
*************************************
All things being equal:

1.Top loaded antennas perform marginally better than base loaded

2.Taller antennas (less loading coil) perform better than shorter

3. Thicker antennas perform marginally better than thinner.

4. More conductive antenna stock makes a marginal difference
over less conductive antenna stock.

5. A higher antenna mount works better than a lower mount.

6. A free and clear antenna mount works better than an obstructed one.

7. A more substantial RF ground works better than a minimal ground.

8. A vertical antenna performs better than a diagonal (windblown).



Have you ever opened a book?

Now if any one could come up with a formula that includes all of
these factors then we would be able to answer your question. There
is no formula. However we can say this.
The best mobile antenna is a thick stiff nine foot whip that is
silver coated and mounted on top of the roof with multiple radial
grounding points.
No one is going to use the antenna above in the real word, so one
might draw the conclusion that in the real world we might substitute a
102" stainless whip for the best real world performance. WRONG.
The 102" is made of stainless. Stainless has only 3% the
conductivity of copper. This alone will stop the 102" stainless from
being the top performer. Subtract also the fact that the 102"
stainless bends over in the wind and is also a relatively thin
antenna.
So what is the best choice? It appears that for a realistic
antenna, it is a mildly loaded top or center loaded antenna made
of thick conductive materials. There are a few of these ugly looking
antennas around. They do work marginally better than the
102" stainless and have the benefit of being shorter. These
antennas can get as short as five foot and still equal or
outperform the 102" stainless.

A common choice that was overlooked was the 102"
whip made out of fiberglass with copper wire embedded
in it. Due to the lower velocity factor (how fast radio
frequency energy travels though a substance), the
fiberglass version of the 102" whip can actually be 6"
or so shorter than its stainless counterpart. Due to the
shorter length and thicker outer material, it's also
more rigid (stays straighter when the vehicle is in motion).
In practical terms, it doesn't need a spring to achieve
resonance in the CB band, and can usually be shortened
an additional 4" or more depending on where in the
spectum the operator most often operates. For example,
the fiberglass whip (Radio Shack part number 21-905)
is usually 2 to 6 inches shorter than the stainless version
to begin with. It doesn't need a spring. And when
shooting for resonance (lowest SWR with highest field
strength) on Channel 40, it can usually be shortened
an additional 4 inches. If you shorten it from the bottom
instead of the top, the rigidity is improved. So, the end
product very often ends up a full foot shorter than the
108" stainless whip and spring combination as well as
being cheaper because there's no need to pay for a
spring. Not having a spring makes the setup look
nicer and stay straighter too.

Over the years I've taken a number of the 21-905
whips, shortened them 4 inches or so from the bottom,
and coated them with a thin coat of Varathane to
prevent splintering of the fiberglass over time. The
end result looks great, lasts until it gets smacked
low enough and hard enough to break it, and per-
forms very, very well. To outperform it, an antenna
would have to be a closer match to 50 ohms resistive
and have a lower angle of radiation. Few are capable
of that--and none are cheaper or easier to obtain.
--
-------------------------------------------------------------------
-=[Bill Eitner]=-
http://www.cbtricks.com/~kd6tas

-------------------------------------------------------------------

On 25 Oct 2003 02:02:24 +0100, "(Scott Unit 69)"
wrote:


wrote:
*************************************
All things being equal:

1.Top loaded antennas perform marginally better than base loaded

2.Taller antennas (less loading coil) perform better than shorter

3. Thicker antennas perform marginally better than thinner.

4. More conductive antenna stock makes a marginal difference
over less conductive antenna stock.

5. A higher antenna mount works better than a lower mount.

6. A free and clear antenna mount works better than an obstructed one.

7. A more substantial RF ground works better than a minimal ground.

8. A vertical antenna performs better than a diagonal (windblown).



Have you ever opened a book?

Have you ever made sense?

All the above can be gained by a many books. One of
those books was the book of common sense.

Do you have that book?

"Bill Eitner" wrote in message
...

Now if any one could come up with a formula that includes all of
these factors then we would be able to answer your question. There
is no formula. However we can say this.
The best mobile antenna is a thick stiff nine foot whip that is
silver coated and mounted on top of the roof with multiple radial
grounding points.
No one is going to use the antenna above in the real word, so one
might draw the conclusion that in the real world we might substitute a
102" stainless whip for the best real world performance. WRONG.
The 102" is made of stainless. Stainless has only 3% the
conductivity of copper. This alone will stop the 102" stainless from
being the top performer. Subtract also the fact that the 102"
stainless bends over in the wind and is also a relatively thin
antenna.
So what is the best choice? It appears that for a realistic
antenna, it is a mildly loaded top or center loaded antenna made
of thick conductive materials. There are a few of these ugly looking
antennas around. They do work marginally better than the
102" stainless and have the benefit of being shorter. These
antennas can get as short as five foot and still equal or
outperform the 102" stainless.

A common choice that was overlooked was the 102"
whip made out of fiberglass with copper wire embedded
in it. Due to the lower velocity factor (how fast radio
frequency energy travels though a substance), the
fiberglass version of the 102" whip can actually be 6"
or so shorter than its stainless counterpart. Due to the
shorter length and thicker outer material, it's also
more rigid (stays straighter when the vehicle is in motion).
In practical terms, it doesn't need a spring to achieve
resonance in the CB band, and can usually be shortened
an additional 4" or more depending on where in the
spectum the operator most often operates. For example,
the fiberglass whip (Radio Shack part number 21-905)
is usually 2 to 6 inches shorter than the stainless version
to begin with. It doesn't need a spring. And when
shooting for resonance (lowest SWR with highest field
strength) on Channel 40, it can usually be shortened
an additional 4 inches. If you shorten it from the bottom
instead of the top, the rigidity is improved. So, the end
product very often ends up a full foot shorter than the
108" stainless whip and spring combination as well as
being cheaper because there's no need to pay for a
spring. Not having a spring makes the setup look
nicer and stay straighter too.

Over the years I've taken a number of the 21-905
whips, shortened them 4 inches or so from the bottom,
and coated them with a thin coat of Varathane to
prevent splintering of the fiberglass over time. The
end result looks great, lasts until it gets smacked
low enough and hard enough to break it, and per-
forms very, very well. To outperform it, an antenna
would have to be a closer match to 50 ohms resistive
and have a lower angle of radiation. Few are capable
of that--and none are cheaper or easier to obtain.
--
-------------------------------------------------------------------
-=[Bill Eitner]=-
http://www.cbtricks.com/~kd6tas

-------------------------------------------------------------------


DON NOT put more than about 100 watts into one of those RS fiberglass whips!
They work well at low power...........but are not made for high power
applications.
Train

*************************************
All things being equal:

1.Top loaded antennas perform marginally better than base loaded

2.Taller antennas (less loading coil) perform better than shorter

3. Thicker antennas perform marginally better than thinner.

4. More conductive antenna stock makes a marginal difference
over less conductive antenna stock.

5. A higher antenna mount works better than a lower mount.

6. A free and clear antenna mount works better than an obstructed one.

7. A more substantial RF ground works better than a minimal ground.

This is true but I have seen installations that were actually OVERGROUNDED
and hurt performance.

8. A vertical antenna performs better than a diagonal (windblown).

Number 5, 6, & 8 are the most important factors in the performance of
an antenna.


Now if any one could come up with a formula that includes all of
these factors then we would be able to answer your question. There
is no formula. However we can say this.
The best mobile antenna is a thick stiff nine foot whip that is
silver coated and mounted on top of the roof with multiple radial
grounding points.
No one is going to use the antenna above in the real word, so one
might draw the conclusion that in the real world we might substitute a
102" stainless whip for the best real world performance. WRONG.
The 102" is made of stainless. Stainless has only 3% the
conductivity of copper. This alone will stop the 102" stainless from
being the top performer. Subtract also the fact that the 102"
stainless bends over in the wind and is also a relatively thin
antenna.
So what is the best choice? It appears that for a realistic
antenna, it is a mildly loaded top or center loaded antenna made
of thick conductive materials. There are a few of these ugly looking
antennas around. They do work marginally better than the
102" stainless and have the benefit of being shorter. These
antennas can get as short as five foot and still equal or
outperform the 102" stainless.

Percent conductivity of materials, based on copper being the standard
of 100%

Aluminum 65%
Brass 28%
Chrome 74%
Gold 71%
Iron 17%
Silver 106%
Steel 10%
Stainless 3%
**************************************

So.....Why has there not been a SS 102 with a heavy silver plate?
K-40 was using silver plating in their load coils in the 70's
and that hasn't changed as far as I know.
Train

On Sat, 25 Oct 2003 11:54:32 GMT, "Train" wrote:

*************************************
All things being equal:

1.Top loaded antennas perform marginally better than base loaded

2.Taller antennas (less loading coil) perform better than shorter

3. Thicker antennas perform marginally better than thinner.

4. More conductive antenna stock makes a marginal difference
over less conductive antenna stock.

5. A higher antenna mount works better than a lower mount.

6. A free and clear antenna mount works better than an obstructed one.

7. A more substantial RF ground works better than a minimal ground.

This is true but I have seen installations that were actually OVERGROUNDED
and hurt performance.

How are why would that occur?


8. A vertical antenna performs better than a diagonal (windblown).

Number 5, 6, & 8 are the most important factors in the performance of
an antenna.


Now if any one could come up with a formula that includes all of
these factors then we would be able to answer your question. There
is no formula. However we can say this.
The best mobile antenna is a thick stiff nine foot whip that is
silver coated and mounted on top of the roof with multiple radial
grounding points.
No one is going to use the antenna above in the real word, so one
might draw the conclusion that in the real world we might substitute a
102" stainless whip for the best real world performance. WRONG.
The 102" is made of stainless. Stainless has only 3% the
conductivity of copper. This alone will stop the 102" stainless from
being the top performer. Subtract also the fact that the 102"
stainless bends over in the wind and is also a relatively thin
antenna.
So what is the best choice? It appears that for a realistic
antenna, it is a mildly loaded top or center loaded antenna made
of thick conductive materials. There are a few of these ugly looking
antennas around. They do work marginally better than the
102" stainless and have the benefit of being shorter. These
antennas can get as short as five foot and still equal or
outperform the 102" stainless.

Percent conductivity of materials, based on copper being the standard
of 100%

Aluminum 65%
Brass 28%
Chrome 74%
Gold 71%
Iron 17%
Silver 106%
Steel 10%
Stainless 3%
**************************************

So.....Why has there not been a SS 102 with a heavy silver plate?
K-40 was using silver plating in their load coils in the 70's
and that hasn't changed as far as I know.
Train


Just cover the S/S whip with copper braid. Copper is almost as good
as silver.

How can you shorten a fiberglass whip from the bottom??? I am interested in
trying it

snip
So.....Why has there not been a SS 102 with a heavy silver plate?
K-40 was using silver plating in their load coils in the 70's
and that hasn't changed as far as I know.
Train


Just cover the S/S whip with copper braid. Copper is almost as good
as silver.

Yes, and when you do this nothing shorter will beat it.

tnom,
Except to 'stir the pot' why would you want to drag
out this collection of out dated misconcepts? Mixing
a little bit of truth with a lot of old 'wive's tales'
is a sure way to spread confusion and mis-information.
In that respect you're doing a fine job...
'Doc