mobile antenna to base !

[Riverman]

That video method won't work for me.

No way are those guys in north Texas. Our clay here is now officially a tick denser than Class A concrete.

And using water outdoors for something like that is against the law right now.
Every drop is precious.

 

[222DBFL]

Wow didn't realize things were that bad there Riverman!! We haven't had a bad drought here for a while, the last one there were A lot of big fires. I totally understand having the water restrictions. Do what you can, the dipole is probably going to be your best bet. Get a good matching balun and hang it up.

 

[Lil'Yeshua]

Usually when Texas is experiencing a drought we in the southeast have rain rain and more rain but I've seen Texas have floods when the southeast experiences a drought.
I live just when the soil becomes all sand. Last night when I got home after a storm there was water pooled in low spots.

 

[Riverman]

Our city has hired a firm to perform cloud seeding and another to squirt some goo on our lakes to slow down evaporation.

But enough of that. It's too depressin'.

Since this thread is titled Mobile Antenna to Base, I guess this question is appropriate:

If I decide to try my hand at making another homemade groundplane (made on once using 4' Firestiks), which would be better for the vertical: 102" steel whip or the 7-foot Firestik. Although the Firestick would be about a foot and a half shorter, it's top-loaded. Seems like that would be desirable.

Antenna mast is 15'.

 

[Lil'Yeshua]

Our city has hired a firm to perform cloud seeding and another to squirt some goo on our lakes to slow down evaporation.

But enough of that. It's too depressin'.

Since this thread is titled Mobile Antenna to Base, I guess this question is appropriate:

If I decide to try my hand at making another homemade groundplane (made on once using 4' Firestiks), which would be better for the vertical: 102" steel whip or the 7-foot Firestik. Although the Firestick would be about a foot and a half shorter, it's top-loaded. Seems like that would be desirable.

Antenna mast is 15'.

I ran a SS 102" whip on my tower utilizing the twin stacked deep fringe tv yagi's underneath it in substitute for radials until I took all of that down and put up my A99 with the GPK(ground plane kit) and substituted the four 6' fiberglass radials that came with it for four SS 102" Rat Shack whips I had previously bought for another antenna project.
The A99 gained me 2 S-units higher than the 102" SS whip config previously installed.
With the 102" SS whip config I could still talk locally and do some skip as well. There are others that use the 102" SS whip as a base antenna. I'm just saying that the A99 provided a big boost gain wise as compared to the 102" SS whip antenna.
My suggestion would be to go as big as you can unless you deem yourself restricted in this area then knock yourself out with your present experimentation ideas. The pic below is my A99 calculated courtesy of Marconi

 

[Rick330man]

What I want to know is: how does a 102" whip as a vertical radiator with the 4 ground plane radials (essentially a Starduster configuration) compare to the A99?

 

[222DBFL]

Rick330man, look at the post above yours, Lil'Yeshua already posted his results, the a99 works better than a 102" as whip with a gpk kit. Yeshua, the enzec model shows 108" ss whips being used, did you have to add 6" of spring or did you just use 102" whips for the gpk kit for your a99? I too am curious if it's worth it. I have an old a99 and it's about 36ft to tip, wondering how well a gpk kit would work for me? Anybody with any response it is much appreciated. God bless.

 

[Lil'Yeshua]

Rick330man, look at the post above yours, Lil'Yeshua already posted his results, the a99 works better than a 102" as whip with a gpk kit. Yeshua, the enzec model shows 108" ss whips being used, did you have to add 6" of spring or did you just use 102" whips for the gpk kit for your a99? I too am curious if it's worth it. I have an old a99 and it's about 36ft to tip, wondering how well a gpk kit would work for me? Anybody with any response it is much appreciated. God bless.

The GPK kit comes with four 6' fiberglass whips. I used four 102" SS Radio Shack whips I had. The big guns will say that radial kit will provide little more than to keep common mode currents traveling down the coax to a minimum. Also,the A99 has a high loss tuning section but if you step up to a Imax 2000,it's tuning section doesn't have as many turns on it's coils.
I had a discussion with an fellow CB'er about my config. He said if I had a whole lot more radials than the four then the antenna would perform a lot better and get he antenna up higher.

You might want to wait until the heavyweights weigh in on this manner as they have the knowledge and expertise to answer your questions. I'm just a rookie.


Here's the reference for my A99 antenna project.
http://www.worldwidedx.com/cb-antennas/17279-firestik-fire-up-99-has-anyone-tried-one.html

 

[222DBFL]

Thanks for the fast reply sir. Much appreciated.

 

[Riverman]

All good info.

I'm reluctant to get the 99 for two reasons. It's a little too tall for the wife and neighbors. And from the many posts I've read, with the 99 my neighbors will be hearing me on their stereos and watching me on TV.

Any ideas on the 7' Firestik vs steel whip?

 

[Lil'Yeshua]

All good info.

I'm reluctant to get the 99 for two reasons. It's a little too tall for the wife and neighbors. And from the many posts I've read, with the 99 my neighbors will be hearing me on their stereos and watching me on TV.

Any ideas on the 7' Firestik vs steel whip?

Somebody else will have answer that question. You could do a forum search.
Copper Talk: Fire Stick
Van Ordt power sticks:
Mobile Antennes

 

[Riverman]

Yeshua,

I found this on one of the links you gave me.

Posted on Saturday, February 22, 2003 - 6:04 am: (Moderator/Admin Only)

I have used my 2 KW7 Firesticks for over 16 years as both mobile and base antennas. They are one of the best antennas you can buy if you use them correctly (read as follow the directions).

I have talked worldwide on them with no problems, they are immune to all types of weather and require very little if any maintenance other then a wipe down with a squirt of WD40 once a year.

There is no way a 1/4 wave whip can even come close to the DX talk power of a KW7 Firestick. As for SWR I have never seen higher then 1.3 across the entire 27mhz band myself.

They are very easy to trim to the resonate frequency you want, for me that's 27.505 where SWR is 1.1 and continues at that reading for quite a ways on either side.

I suggest you go read the install information that is available online at the Firestick website for answers as to why you might be having problems with these antennas because I have tried most of the competitors at one time or another and I always end up back using my old Firesticks.

I think I might try one rather than a steel whip.

Will post my findings if I do.

Thanks for your help.

 

[The DB]

What I want to know is: how does a 102" whip as a vertical radiator with the 4 ground plane radials (essentially a Starduster configuration) compare to the A99?

Here are some models that show a comparison.

A few notes to cover first...

1) All models below are fed 1/2 wavelength over average ground, with one exception, and that is one of the Starduster models was raised the tip height for a tip to tip comparison to the a99.

2) The Starduster models do not include a matching network as their match to the feedline is naturally close enough that they don't need one.

3) The a99 models do have matching networks, they all have L networks for consistency. These matching networks are more efficient than the a99 matching network, and because of that the gain shown by all of the a99 models will be higher than in the real world.

4) These models are assuming a non-conductive mast and an ideal choke for the feedlines. Currents on a conductive mast and the outside of the feedline will have an effect on the patterns.

Now that that is out of the way on with the show...

First the Starduster models:

The red plot is the starduster at the same feedpoint height as the a99's below. The blue one was moved up to the tip height of the a99 models below.

Now the a99 plots:

The blue plot has no radials, the red plot has horizontal 1/4 wavelength radials, the green plot has angled 1/4 wavelength radials at 45 degrees, and the pink plot has angled 6 foot radials at 45 degrees.

I think most people can figure it out from there. Remember, the a99 gain figures are optimistic figures due to its lossy matching network. I would estimate .3 to .5 dB of additional losses due to that lossy component, and I think that is a conservative estimate.

Hope this helps.


The DB

 

[The DB]

There is no way a 1/4 wave whip can even come close to the DX talk power of a KW7 Firestick.

Saying any shortened mobile antenna is better than a full sized 1/4 wavelength whip is wishful thinking at best. To say that they are close enough that you won't notice a difference is one thing, but to say outperforms? That flies in the face of well known, and well tested, antenna theory.

About the only potential benefit I can see a shorter antenna having over a longer one in a mobile environment is it is *possibly* better able to use the inadequate ground plane that is the vehicle's body.

Would you mind posting a link to that post/page?


The DB

 

[Lil'Yeshua]

Saying any shortened mobile antenna is better than a full sized 1/4 wavelength whip is wishful thinking at best. To say that they are close enough that you won't notice a difference is one thing, but to say outperforms? That flies in the face of well known, and well tested, antenna theory.

About the only potential benefit I can see a shorter antenna having over a longer one in a mobile environment is it is *possibly* better able to use the inadequate ground plane that is the vehicle's body.

Would you mind posting a link to that post/page?


The DB

Information vs. ????
I think this is the reference material for that statement.
KW7 Performance vs 102" whip -- ©1997 FIRESTIK® ANTENNA