Grounding Inverted Vee

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xwindows2

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I am putting up an inverted vee on my roof,the apex will be about 35' above ground,each leg 45' long
My question is how can I ground this type of antenna?
I will also use MFJ-913 balun and 14 gauge copper flexweave
 

benbenrf

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xwindows2

The 2 diagonals terminate at their respective base/lower ends with insulators i.e. neither goes to ground - you know that I guess(?)

One of those diagonals is your radiating element (I guess you know that too), the other diagonal, like the radiating diagonal, connects through the balun to the coax: the radiating diagonal to the the coax inner core, and the other diagonal to outer sheath, and then on through the coax to the receiver chassis (thru the receiver coax connector securing thread) - that is you antenna GROUND.

Note

- the diagonals should be spread by at the very least 70degrees, and if I recall correctly, ideally by something like 110, but on this latter figure, I stand to be corrected. Just make sure you have at least 70degrees at the apex. I know that if the spread is more than around 115-120degrees your radiation pattern is fast heading towards that obtained with a conventional dipole.

- the top end of the diagonal wires must also be insulated (from the mast)

- do not mounted an Inverted-V over a tin/steel or similar material roof covering - this is an inverted-V, not a Half Rhombic! (which has a wire running between the bottom of the 2 diagonals!).

PS - curious: what freq/s are you designing this Inverted-V for?

All the best
 
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prcguy

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My question would also be what is the antenna going to do with 45ft long elements? You might want to ground the antenna per NEC for some lightning protection using an appropriate lightning arrestor but an inverted V doesn't require a ground otherwise.

Keep in mind that in most cases the far ends of inverted V elements end up too close to the ground compared to a flat top horizontal dipole and therefor will loose some efficiency.

If this antenna is for multiband SW reception or for HF amateur use it would be better off fed with balanced line and maybe a balun at the radio end.
prcguy
 

xwindows2

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I am trying to get better reception 75-m through 10m
right now i use a 45ft long recieving antenna from par electronics has a built in balun,fed with 40ft rg8x
and it's grounded to one of mast on the roof.The other end of the roof has a 6ft scanner ground plane on it
works pretty well for 30-50 mhz,this is where i will mount the inveted vee,about 5 ft below ground plane
with each leg tied off to a tree. Did i make a mistake and buy a balun that i dont need
Is this type of antenna good for general recieve sw and ham hf bands
I am using icom R75,eventually want to get my ham ticket and transmit with this inverted vee
Not sure if should use ladder line to feed antenna and no balun
Thank you again
 

zz0468

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Is this type of antenna good for general recieve sw and ham hf bands
If you do it right, it'll work fine. Open wire feed to a balun, coax from the balun to the radio. Ground the coax as recommended in plenty of on-line references. the antenna itself is balanced, and doesn't require a ground.

I've used balance fed dipoles for general coverage RX and found that they work pretty good. If one was to plot patterns and VSWR, it would be all over the map as frequency changes, but in practice, it's relatively easy, and, in my experience, works just fine.

I am using icom R75,eventually want to get my ham ticket and transmit with this inverted vee
In the case of transmitting, you could replace the balun with a tuner of some sort. Coax from the radio to the tuner, balanced line from the tuner to the antenna. This would give you pretty decent multiband coverage. This is what I use, the tuner being an SGC autotuner. I get pretty decent performance from 160 meters to 10 meters on what amounts to a 40 meter dipole fed with open wire line.

Not sure if should use ladder line to feed antenna and no balunThank you again
The balun is essential for satisfactory performance if you're using ladder line.
 

benbenrf

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Is the Inverted-V any good for reception?

Like all antenna's the Inverted-V it has pro's & cons. In respect of HF listening, the primary issue for users has always been one of avaliable space versus frequency – so while there are a dozen other designs that could do a better job, unless one has the space to set them up in it's a pointless exercise arguing this antenna or that antenna would be better. At the end of the day all HF antenna's are a compramise to some extent.

Choose one that you feel you are going to be happy with, and then go about setting it up properly. Personaly I like loops – okay, they gain well into the minus side, but designed properly thats seldom an issue because they can be so quiet.

50Ohm or 300Ohm feed(?)
I'll comment from a personal opinion perspective – thats all it is, a personal opinion: I'd go for a 450 Ohm ladder feeding matching stubs made of 300Ohm 1/4wavelength foam core (in parrellel), which in turn connect to a correctly sized coaxial balun, which then connects to your receiver coax input. If you're going for your ticket best go read up all about this way of connecting your Inverted V to the radio i.e. lengths of the various sections. This “step-down” method is inherently resistant to noise (its one of the quietest ways of connecting low effiecency HF antenna's to radios) and signal loss is next to nothing – you could quite easily set your antenna up 300 – 500 feet away from the radio and the losses would be negligiable.

There are of course other ways of connecting HF antenna's to radios – the above is just the way I'd go about it – like antenna choice, connection choices all have disadvantages and advantages (there is no one perfect antenna and there is no one perfect way to connect it to the radio). The disadvantage here (?) – the coaxial balun section length/s are frequency dependent – but then if you are going to be working different HF bands, so too are the lengths of the Inverted-V diagonals!
 

xwindows2

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I used 96 ft total wire length,I wanted to go longer but my lot doesn't allow me
I did a quick temp. install,apex is 30ft above ground and 5 ft above the roof both end 45 degree and 10ft above ground
This is quieter than my 45ft par electronics wire w/built in balun
 

xwindows2

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Ok here is my latest Inverted attempt,the apex is up 36 ft Running north and south and 4:1 balun and rg8x coax 50 ft.The ends are about 40 deg.and 15ft above ground, total length is 100'.Thats all i have room for.But i am still confused, about the balun
4:1 or 1:1 with open feed line 300ohm
I like 20 and 40 meters,eventually use this to transmit,This antenna should resonate around 4.50 mhz
In other words i didnot cut this for band specific,just used as much wire i can get up in the air
Please advise
 
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