Predator Competition "Bad to the Bone"

[BOOTY MONSTER]

Yep...But there's no benefit to doing it, other than making the antenna shorter.

that's the coils job .

 

[jessejamesdallas]

that's the coils job .

Right...But having the stinger side-ways, your another couple of feet shorter!

 

[BOOTY MONSTER]

what's the purpose of the horizontal stinger ?

 

[jessejamesdallas]

what's the purpose of the horizontal stinger ?

No clue...Think it was suppose to mimic a flat-side base antenna...Predator is not the only one who has built these either...Bad Boy has a version...not sure about Mr. Coily.

 

[10k223]

The "horizontal stinger" is a capacity hat. There is actually nothing horizontal about this antenna except for the fact that the stinger is oriented that way. This is a short, coil and cap hat loaded vertical antenna. There's nothing wrong with building a coil loaded antenna and using a cap hat set some distance above the coil if you need to make a shortened antenna. However, he could have made just one coil with a reasonable Q and it would work a lot better. That second, long skinny coil is the biggest problem with the whole design. For the cap hat, he could add multiple elements to add more capacitance if the hat was getting too large. That would have helped cut down on the size of the coil, as well.

Whatever the case, it sure was talking good skip today on just 1k.

 

[mackmobile43]

Whatever the case, it sure was talking good skip today on just 1k.

I did not have the same results with mine so I switched back to the regular 10-k with a 27'' shaft and went up 3 s-units to the same guy in dx and 5 s-units to a local.

 

[office888]

what's the purpose of the horizontal stinger ?

Turning watts into heat.

 

[Shockwave]

I wonder how that amplified coil voltage that boasts audio works on deviation for FM? It probably has some detector built in so it would only amplify the frequency deviation on FM and keeps the frequency stable with a built in standard 3 terminal voltage regulator on SSB.

 

[W5LZ]

... Don't know about the FM thingy, but it makes the colors more vibrant on SSTV. Sharper edges, you know?
- 'Doc

 

[BOOTY MONSTER]

Whatever the case, it sure was talking good skip today on just 1k.

i've had the same experience with a uniden 78ltw barefoot into a little wil centered on the roof .
i just chalked it up to conditions .

 

[AudioShockwav]

The worst part of that Idea is the small Coil with the long wire acting as a top hat.
This is about the worst case of loading you can do.
It actually decreases the current flowing through the coil, in some cases by up to 25%
In that case, the Coil was 12 inches long, 1.5 inches in dia, with a 24" Cap hat mounted just above the coil.
As the horizontal whip is simply acting as the same thing, it fits the description of the antenna that Mole posted.

I don`t doubt it works, but you are wasting power in the coil that could be adding to your signal.

i've had the same experience with a uniden 78ltw barefoot into a little wil centered on the roof .
i just chalked it up to conditions .

I agree with you Booty, a $25 center loaded mag mount will work DX if the band is open.
By now we all know that testing antennas by shooting skip is worthless.
to many variables.


73
Jeff

 

[pro151]

I love antenna discussions. Kind of like Ford/Chevy/Dodge discussions.

As my mentor told me years ago..."Hell boy, you can work skip with 2 watts and a coat hanger"

 

[MrSuburban]

Whatever the case, it sure was talking good skip today on just 1k.

my walkie talkie talks good skip too

 

[Moleculo]

If you need to shorten a mobile antenna for whatever reason, the antenna will have greater efficiency if you can use a capacity hat and decrease the amount of coil. The larger the hat, the better, but it becomes unmanageable at some point when it becomes too large. You can add more capacitance by using more hat elements. Here are a few ideas that are in the marketplace:

Here are some simple, proven rules you can use to help designing more efficient short, loaded antenna:

1. Use Cap hats
2. Use coils that are short and wide rather than long and skinny
3. Don't put a cap hat directly on top of a coil - some separation is necessary
4. Don't mix and match coil sizes on the same antenna if you can help it. Doing so may be necessary if you're building multiband antennas (think traps, etc.), but there's no reason to do it on a single band antenna.
5. Don't make up your own descriptions for how it works when you're done. It's OK if you don't fully understand what you created (happens to me all the time), but don't make shit up.

 

[Robb]

OK . . . So how will a large capacitive hat affect an antenna radiation pattern?

Surely it must be less uniform . . . So how is that more efficient?

Or are we talking about a trade-off?