Wilson 5000 vs Fiberglas 5/8 1000 & 102" Q's.

[The DB]

Is that the one where they use a 5/8'th wavelength of wire to make the antenna? I know that there are several out there that do that. Or was that the one that uses several shorter lengths in parallel?

The wavelength of the antenna is what determines the radiation pattern, at least before other factors do their part. The thing is, it doesn't matter if 22' or 10,000' of wire was used, if it is in an antenna 5' long it will have the radiation pattern of a 5' antenna.

Also don't forget, the manufacturer is using that as advertising. The purpose of advertising is to get you to purchase an item, not tell you the truth about it.

Put it up against a 1/4 wave ground plane antenna and see which one performs better. If the advertising you believe to be true is correct it should outperform the 1/4 wave antenna. It doesn't, and it never has.

If those antennas actually performed like a 5/8 wave antenna, why haven't they started selling them as a base antenna replacement? There are people that I'm sure would love a 5' antenna that works as well as a 22' antenna for concealability purposes, such as apartment buildings or residential neighborhoods that force you to sign some form of limiting contract.

Seriously though, in the end, believe what you want. This, however, is nothing more than snake oil, and you just bought it.


The DB

 

[The DB]

Put it up against a 1/4 wave ground plane antenna and see which one performs better.

And by that line I am referring to an actual full length 1/4 wave ground plane antenna, not one that has to be loaded with coils to get the 1/4 wavelength.


The DB

 

[Robb]

I wouldn't worry too much about being suckered in by some of the more 'colorful' advertising claims. Everybody has to start out somewhere and has to learn. It is a lot to learn, if you consider the depth of it all carefully too.

Some will say that learning CB is simpler. I would disagree with that. The same electrical principles at work in Ham radio are also responsible to understand Ham radio.

As far as this antenna is concerned, like others have said 'if it works for you; then go with it'. I think that it is important to first realize that ANY mobile antenna that is less than a 1/4 wave/~9ft long - is a compromise of both receive and transmit capabilities. If you want real performance for your big rig; then a 1/4 stainless steel whip - or two of them in a co-phase setup - would yield the best possible performance.

The rest of the antennas that are less than a 1/4 - and their mfrs - are just not capable of matching the same performance tit-for-tat. Its not personal; just electrical . . .

 

[Mr Clean]

Get a preditor 10k for that big truck. They work great are stong lite and rebuildable if something does happen to it.

 

[Freightlinerbob]

Actually, simple arithmetic led me to buy the antenna. A factory mount set at 8'6" and a 13'6" height restriction meant that a 5' antenna was in order, because the only thing I know about antennas is that commercial radio stations put theirs as high as possible

You guys claim that antennas can only handle 50% of their advertised rating and that amps make 50% of their output.

Who am I to argue.

But, if I mention a 5000 watt antenna or 350 watt amp you understand and leave it alone, but I refer to a 5/8 wave antenna ( cause thats what it's called)and you get all theoretical on me and start assuming all sorts if stuff.

 

[The DB]

Actually, simple arithmetic led me to buy the antenna. A factory mount set at 8'6" and a 13'6" height restriction meant that a 5' antenna was in order, because the only thing I know about antennas is that commercial radio stations put theirs as high as possible

Good.

You guys claim that antennas can only handle 50% of their advertised rating and that amps make 50% of their output.

Who am I to argue.

When did I claim that? I will say pushing an antenna to its limit consistently can cause issues.

But, if I mention a 5000 watt antenna or 350 watt amp you understand and leave it alone, but I refer to a 5/8 wave antenna ( cause thats what it's called)and you get all theoretical on me and start assuming all sorts if stuff.

With the 5000 watt antenna you mentioned or the 350 watt amp, not necessarily. It depends on the details in question. For example, a Wilson 5000 magnet mount antenna, if you look up the specifications on the coax used it will not handle anywhere near 5000 watts.

An antenna is what it is, and just because a manufacturer calls something a 5/8 wave antenna does not make it so. No theory involved, just fact.

It is a fact that to be a 5/8 wave antenna it needs to be more than four times longer than that antenna is. No theory there, simply fact. It does not matter how long the wire(s) used to make the antenna are, the only thing that matters here is its actual length of the antenna. Length is everything. A 5/8 wave antenna is more than 20 feet long, this one is not. Because of this it will not have the radiation pattern or the gains of an actual 5/8 wave antenna.

The way you are talking it is almost like you want to believe. Well this is a free country, believe all you want, but you have been exposed to the truth.


The DB

 

[Freightlinerbob]

Actually, I don't "want" to believe anything about the antenna I bought. I really don't care what it is or what it is called. I some of you actually read my original question.....you would understand what I'm asking.

 

[2RT307]

Antenna theory makes my head hurt. But I have wondered, since I have run a Wilson silverload 5' antenna, and currently run a Firestik 5' one... isn't it supposed to be better to have the load above the vehicle? So, in his (and my) case, the top loaded antenna has the load above the cab of the truck.

Isn't this "theoretically" supposed to work better than say, a base load Wilson 5000 mounted in the same position on the vehicle?

73,
RT307

 

[Brake Weight]

I've got a 7' Firestik I'll throw on every now and again.

 

[The DB]

Antenna theory makes my head hurt. But I have wondered, since I have run a Wilson silverload 5' antenna, and currently run a Firestik 5' one... isn't it supposed to be better to have the load above the vehicle? So, in his (and my) case, the top loaded antenna has the load above the cab of the truck.

Isn't this "theoretically" supposed to work better than say, a base load Wilson 5000 mounted in the same position on the vehicle?

73,
RT307

It is commonly said to have any loads above any obstructions caused by the vehicle.

However, when choosing an antenna setup you should also take into account that on a quarter wave or shorter antenna the part of the antenna that radiates the most RF energy is the bottom that is near the obstruction.


The DB

 

[KC9RLK]

It doesn't matter what the manufacturer calls it, that is not a 5/8 wave length antenna in any way. It's only 5 feet long, not 22 feet, so it can't be a 5/8 wave antenna. It's not even a 1/4 wave, 4 feet too short. Sorry, but the radiation pattern of an antenna is dependent on it's physical length, not it's 'advertised' length or it's 'name'. You can call your cat 'Rover', but it still ain't gonna bark...
- 'Doc

It's my understanding that all fiberglass whips have approximately 102" of copper wire wrapped around them, that is why you see the coiled wire underneath the sheathing being tighter at the top or looser depending on its length.

 

[KC9RLK]

It is commonly said to have any loads above any obstructions caused by the vehicle.

However, when choosing an antenna setup you should also take into account that on a quarter wave or shorter antenna the part of the antenna that radiates the most RF energy is the bottom that is near the obstruction.


The DB

That's because the coil is where the RF signal loses its gain so a coil at the bottom loses gain before it gets to the top of the antenna. A top-loaded antenna with the coil at the top doesn't lose gain until the signal radiates off the upper section of the antenna. This is not rocket science kids. If you all do your research properly none of these flame wars would even happen.

 

[KC9RLK]

Is that the one where they use a 5/8'th wavelength of wire to make the antenna? I know that there are several out there that do that. Or was that the one that uses several shorter lengths in parallel?

The wavelength of the antenna is what determines the radiation pattern, at least before other factors do their part. The thing is, it doesn't matter if 22' or 10,000' of wire was used, if it is in an antenna 5' long it will have the radiation pattern of a 5' antenna.

Also don't forget, the manufacturer is using that as advertising. The purpose of advertising is to get you to purchase an item, not tell you the truth about it.

Put it up against a 1/4 wave ground plane antenna and see which one performs better. If the advertising you believe to be true is correct it should outperform the 1/4 wave antenna. It doesn't, and it never has.

If those antennas actually performed like a 5/8 wave antenna, why haven't they started selling them as a base antenna replacement? There are people that I'm sure would love a 5' antenna that works as well as a 22' antenna for concealability purposes, such as apartment buildings or residential neighborhoods that force you to sign some form of limiting contract.

Seriously though, in the end, believe what you want. This, however, is nothing more than snake oil, and you just bought it.


The DB

Like they say with car engines, "there's no replacement for displacement". A longer antenna will always outperform a shorter antenna as long as it's properly installed and properly tuned.

 

[The DB]

Wow, you dug these out from the past, even a post from Doc's account which I haven't seen post in a decade or more... Hope hes doing well. Its good to see people still go back and read said posts, a lot of good information in this forums history...

That's because the coil is where the RF signal loses its gain so a coil at the bottom loses gain before it gets to the top of the antenna. A top-loaded antenna with the coil at the top doesn't lose gain until the signal radiates off the upper section of the antenna. This is not rocket science kids. If you all do your research properly none of these flame wars would even happen.

What I was talking about has nothing to do with the loading coil on shortened antennas. In any end fed antenna, the part of the antenna that radiates the most is electrically 1/4 wavelength from the tip of the antenna, which on an electrical 1/4 wavelength antenna is at its feed point. The only exception to this is if you happen to have a loading coil (or some other form of loading) at that point, which will cause the area of peak radiation to be moved to the end of said coil. This electrical 1/4 wavelength from tip rule holds true even for longer antennas like the 1/2 and 5/8 wavelength antennas, the point of peak radiation is electrically 1/4 wavelength down from the tip of the antenna.

Like they say with car engines, "there's no replacement for displacement". A longer antenna will always outperform a shorter antenna as long as it's properly installed and properly tuned.

This is assuming that said antennas are mounted at the same feed point height. Take a 1/4 wavelength antenna and mount it above a 5/8 wavelength antenna and see which one outperforms the other...


The DB

 

[r carl]

Like they say with car engines, "there's no replacement for displacement". A longer antenna will always outperform a shorter antenna as long as it's properly installed and properly tuned.

I heard a woman say that onetime...