Inverted V Question

[Phil501]

Hello all, I have a question regarding my Inverted V that I built last weekend......I found this formula on the internet.

www.hamuniverse.com/dipivcal.html and punched in 27.475 for the freq. It kicked out 8.09 feet, wich is about 8' 3/4".......I went ahead and used the dimensions given.....I constructed the feedline with out a Balun, just a jumper that I had laying around.....The first time I keyed up it was giving me a 1:4 to 1 match......Not bad for first attemt. My question is the length given from formula is a half wave, if I were to take the 8.09 feet and times it by 2, would this give me 1full wave? As some of you know I had to pull down my I-Max 2000 do to CCR restrictions. I put my inverted V in the attic and I'm sure it isn't as good as my groundplane, I just need something to DX a little when the band is opened up........what I was impressed with is the lack of static noise level compared to my I-Max. I had some good contacts last weekend..........Any input would be appreciated.......Thanks

73's

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[Phil501]

Hello all, I have a question regarding my Inverted V that I built last weekend......I found this formula on the internet.

www.hamuniverse.com/dipivcal.html and punched in 27.475 for the freq. It kicked out 8.09 feet, wich is about 8' 3/4".......I went ahead and used the dimensions given.....I constructed the feedline with out a Balun, just a jumper that I had laying around.....The first time I keyed up it was giving me a 1:4 to 1 match......Not bad for first attemt. My question is the length given from formula is a half wave, if I were to take the 8.09 feet and times it by 2, would this give me 1full wave? As some of you know I had to pull down my I-Max 2000 do to CCR restrictions. I put my inverted V in the attic and I'm sure it isn't as good as my groundplane, I just need something to DX a little when the band is opened up........what I was impressed with is the lack of static noise level compared to my I-Max. I had some good contacts last weekend..........Any input would be appreciated.......Thanks

73's

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[W5LZ]

Phil501,

For an inverted 'V' configuration, the length given is a half wave length, and twice that length would be a full wave length. The length of a ~resonant~ half wave length at a particular frequency changes due to several things, diameter of the conductor, the physical relationship between the 'halves' of a dipole, and height above ground. With an SWR of 1.4<img src=http://users.joplin.com/dutch64804/posticon1.gif ALT=":1"> it sounds like yours is about as 'close' as it gets.

An inverted 'V' antenna is essentially an omnidirectional antenna and horizontally polarized. They typically have a higher 'take off' angle than a vertical antenna but the difference isn't all that important, certainly not enough to worry about when looking for 'DX'.

The 'quieter than an Imax' is because of the antenna's polarization. Vertically polarized antennas 'hear' more noise because most man- made noise is vertically polarized. So, in general, a horizontally polarized antenna tends to be 'quieter'. The difference in noise usually isn't all ~that~ great, but there is a difference.

A balun usually isn't necessary with an inverted 'V', the impedance is usually very close to 50 ohms so the impedance matching ability of a balun isn't needed, and the balanced-to-unbalanced thingy just isn't that big'a deal at HF. [About the only affect of using a balun at HF is the shape of the radiation pattern, it'll be slightly 'skewed' at HF not using a balun. Still, not a big deal at HF.]

There's nothing wrong with a 1.4<img src=http://users.joplin.com/dutch64804/posticon1.gif ALT=":1"> SWR but if you want to play with reducing it some, try changing the angle between the legs of the antenna. Shouldn't take much to make a change in the SWR. That 'angle of the dangle' works with any dipole to change the input impedance, by the way, not just an inverted 'V'.

- 'Doc



PS - For the 'purist', or to be really picky, an inverted 'V' antenna is one that has an angle of 90 degrees between the legs. At angles greater than 90 degrees the antenna is called a 'drooping' dipole. At angles less than 90 degrees, it's called a 'dummy load'...




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[W5LZ]

Phil501,

For an inverted 'V' configuration, the length given is a half wave length, and twice that length would be a full wave length. The length of a ~resonant~ half wave length at a particular frequency changes due to several things, diameter of the conductor, the physical relationship between the 'halves' of a dipole, and height above ground. With an SWR of 1.4<img src=http://users.joplin.com/dutch64804/posticon1.gif ALT=":1"> it sounds like yours is about as 'close' as it gets.

An inverted 'V' antenna is essentially an omnidirectional antenna and horizontally polarized. They typically have a higher 'take off' angle than a vertical antenna but the difference isn't all that important, certainly not enough to worry about when looking for 'DX'.

The 'quieter than an Imax' is because of the antenna's polarization. Vertically polarized antennas 'hear' more noise because most man- made noise is vertically polarized. So, in general, a horizontally polarized antenna tends to be 'quieter'. The difference in noise usually isn't all ~that~ great, but there is a difference.

A balun usually isn't necessary with an inverted 'V', the impedance is usually very close to 50 ohms so the impedance matching ability of a balun isn't needed, and the balanced-to-unbalanced thingy just isn't that big'a deal at HF. [About the only affect of using a balun at HF is the shape of the radiation pattern, it'll be slightly 'skewed' at HF not using a balun. Still, not a big deal at HF.]

There's nothing wrong with a 1.4<img src=http://users.joplin.com/dutch64804/posticon1.gif ALT=":1"> SWR but if you want to play with reducing it some, try changing the angle between the legs of the antenna. Shouldn't take much to make a change in the SWR. That 'angle of the dangle' works with any dipole to change the input impedance, by the way, not just an inverted 'V'.

- 'Doc



PS - For the 'purist', or to be really picky, an inverted 'V' antenna is one that has an angle of 90 degrees between the legs. At angles greater than 90 degrees the antenna is called a 'drooping' dipole. At angles less than 90 degrees, it's called a 'dummy load'...




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[Phil501]

Hey Doc, Thanks for the insight......Very informative info you gave me.....This whole wire thing is new to me but I'm impressed at what you can gain just by some little pieces of wire....I talked to Dana (DJ 956) last week and he Emailed me some cool links:

www.hamuniverse.com/dipivcal.html



QuietFlex WIRE

www.antennasmore.com/wire&.htm



Inverted "V"

www.qsl.net/w4sat/othwire.htm



www.thewireman.com/products.html



www.radioworks.com/

Jay in the Mohave and Eddie (Marconi) also gave some good info to me......Thanks guys.....Hey Doc right I'm using some 12g multistrand wire I picked up for about $4.00 at the local hardware store..I got some 12g solid copper wire from a friend. What effects does solid wire have compared to multistrand.........I'll play around with the angle this weekend.......I plan on building the 1 full wave as well........Thanks again Doc for the insight............73's

</p>

 

[Phil501]

Hey Doc, Thanks for the insight......Very informative info you gave me.....This whole wire thing is new to me but I'm impressed at what you can gain just by some little pieces of wire....I talked to Dana (DJ 956) last week and he Emailed me some cool links:

www.hamuniverse.com/dipivcal.html



QuietFlex WIRE

www.antennasmore.com/wire&.htm



Inverted "V"

www.qsl.net/w4sat/othwire.htm



www.thewireman.com/products.html



www.radioworks.com/

Jay in the Mohave and Eddie (Marconi) also gave some good info to me......Thanks guys.....Hey Doc right I'm using some 12g multistrand wire I picked up for about $4.00 at the local hardware store..I got some 12g solid copper wire from a friend. What effects does solid wire have compared to multistrand.........I'll play around with the angle this weekend.......I plan on building the 1 full wave as well........Thanks again Doc for the insight............73's

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[Lazybones1222]

To balun or not to balun, that my son, is the question. <img src=http://users.joplin.com/dutch64804/posticon26.gif ALT=":26">

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[Lazybones1222]

To balun or not to balun, that my son, is the question. <img src=http://users.joplin.com/dutch64804/posticon26.gif ALT=":26">

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[Moleculo]

BTW, I was talking to Jay recently who has been doing A LOT of testing with different kinds of baluns on his new beam. He has some interesting experiences doing field testing to determine which types of baluns have favorable effects and which ones have adverse effects on the beam's pattern and other performance characteristics. He's even tested with the supposedly great Amidon baluns only to get irritated with their effect on the beam's performance. I don't think he's done with his analysis yet, but it goes to show you that not everything is in the books nor can be learned from the books. If that were the case, we'd all still think the earth was flat...<img src=http://users.joplin.com/dutch64804/rollingaround.gif ALT=":rollingaround">


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[Moleculo]

BTW, I was talking to Jay recently who has been doing A LOT of testing with different kinds of baluns on his new beam. He has some interesting experiences doing field testing to determine which types of baluns have favorable effects and which ones have adverse effects on the beam's pattern and other performance characteristics. He's even tested with the supposedly great Amidon baluns only to get irritated with their effect on the beam's performance. I don't think he's done with his analysis yet, but it goes to show you that not everything is in the books nor can be learned from the books. If that were the case, we'd all still think the earth was flat...<img src=http://users.joplin.com/dutch64804/rollingaround.gif ALT=":rollingaround">


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[Happy Hamer]

BALUN ESSENTIALS

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[Happy Hamer]

BALUN ESSENTIALS

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[Lazybones1222]

<blockquote>Quote:<hr>Antennas and amps...what works great for some won't work worth a hoot for others.<hr></blockquote>



Ahhhh....words of wisdom.<img src=http://users.joplin.com/dutch64804/yelclap.gif ALT=":yelclap">

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[Lazybones1222]

<blockquote>Quote:<hr>Antennas and amps...what works great for some won't work worth a hoot for others.<hr></blockquote>



Ahhhh....words of wisdom.<img src=http://users.joplin.com/dutch64804/yelclap.gif ALT=":yelclap">

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[Moleculo]

Thread cleaned and re-opened for discussion....on topic please.


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