Topics

End Fed Half Wave setup

Kirt / K7KDW
 

Putting this out there for others to chime in on.

During the New Ham Net tonight a question came up about setting up an End Fed Half Wave in an Inverted L configuration. 

The question was whether it mattered which end the feed point was on. My understanding is that this configuration, the feed point would be on the higher end of the "L". 

My first End Fed was a Chameleon Emcomm portable and I used their documentation on configurations with that and my MyAntennas EFHW. That document is here (PDF Warning) https://www.dropbox.com/sh/8gypgl2px8inh1k/AACF4Wr3LyK-Q5XFX2tHZ-GSa?dl=0&preview=CHA+EMCOMM+III+PORTABLE.pdf

I looked over the doc again but I couldn't find something that answered that question in there so I'm hoping someone else can give an answer to this.

Thanks
Kirt - K7KDW

Ken Kosters
 

Actually I would put the feed point lowest to the ground (Tera ferma) as it would radiate more like vertical, dipole mix rather than inverted vertical beaming into the earth rather than sky. 

Ken

On Jun 27, 2019, at 8:47 PM, Kirt / K7KDW <kirtwhite@...> wrote:

Putting this out there for others to chime in on.

During the New Ham Net tonight a question came up about setting up an End Fed Half Wave in an Inverted L configuration. 

The question was whether it mattered which end the feed point was on. My understanding is that this configuration, the feed point would be on the higher end of the "L". 

My first End Fed was a Chameleon Emcomm portable and I used their documentation on configurations with that and my MyAntennas EFHW. That document is here (PDF Warning) https://www.dropbox.com/sh/8gypgl2px8inh1k/AACF4Wr3LyK-Q5XFX2tHZ-GSa?dl=0&preview=CHA+EMCOMM+III+PORTABLE.pdf

I looked over the doc again but I couldn't find something that answered that question in there so I'm hoping someone else can give an answer to this.

Thanks
Kirt - K7KDW

Shawn / K7ATA
 

Seems more common to feed inverted Ls at the bottom, but every time, some radials are needed.

--Shawn
--K7ATA

On 6/27/2019 8:47 PM, Kirt / K7KDW wrote:
Putting this out there for others to chime in on.

During the New Ham Net tonight a question came up about setting up an End Fed Half Wave in an Inverted L configuration.

The question was whether it mattered which end the feed point was on. My understanding is that this configuration, the feed point would be on the higher end of the "L".

My first End Fed was a Chameleon Emcomm portable and I used their documentation on configurations with that and my MyAntennas EFHW. That document is here (PDF Warning) https://www.dropbox.com/sh/8gypgl2px8inh1k/AACF4Wr3LyK-Q5XFX2tHZ-GSa?dl=0&preview=CHA+EMCOMM+III+PORTABLE.pdf

I looked over the doc again but I couldn't find something that answered that question in there so I'm hoping someone else can give an answer to this.

Thanks
Kirt - K7KDW

Dan Pflugrath
 

The resonate end fed half wave EFHW antenna can be configured many ways and it will still work well.

 

The optimum is to place the 49:1 transformer near ground level and use an earth ground with the antenna wire cut to 1/2 wavelength at the lowest operating frequency.  The earth ground reduces noise but is not absolutely necessary.  The antenna wire works optimum in an inverted L configuration.  The coax lead in is the counter poise but with the antenna wire cut to 1/2 wavelength very little current flows in the coax counter poise.  Put an RF choke near your radio if you get RF in the shack.  Some radios are more sensitive to it than others.

 

The EFHW works as well as a 1/2 wave dipole but is also has low SWR at the multiples of the lowest operating frequency.   My 40 meter EFHW works with low SWR on 40, 20, 15, 12 and 10 meters.  There are ways to add to the antenna to get 30, 18 if needed.

 

For additional information and assistance see the End Fed Half Wave Facebook page at https://www.facebook.com/groups/EndFedHalfWaveAntennas/.  There is a ham on that page that has done considerable testing to assist with implementation.

 

This is a very popular antenna for Summits On The Air since it requires only one pole and can be either a slopper for 20 and 30 meters or an inverted V for 40 meters.  There are commercial versions available or check out the Facebook page for how easy they are to build.

 

73,

Dan KA7GPP

 

 

 

From: snovarc@groups.io [mailto:snovarc@groups.io] On Behalf Of Kirt / K7KDW
Sent: Thursday, June 27, 2019 8:47 PM
To: snovarc@groups.io
Subject: [snovarc] End Fed Half Wave setup

 

Putting this out there for others to chime in on.

During the New Ham Net tonight a question came up about setting up an End Fed Half Wave in an Inverted L configuration. 

The question was whether it mattered which end the feed point was on. My understanding is that this configuration, the feed point would be on the higher end of the "L". 

My first End Fed was a Chameleon Emcomm portable and I used their documentation on configurations with that and my MyAntennas EFHW. That document is here (PDF Warning) https://www.dropbox.com/sh/8gypgl2px8inh1k/AACF4Wr3LyK-Q5XFX2tHZ-GSa?dl=0&preview=CHA+EMCOMM+III+PORTABLE.pdf

I looked over the doc again but I couldn't find something that answered that question in there so I'm hoping someone else can give an answer to this.

Thanks
Kirt - K7KDW



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Ryan - KJ7GIE
 
Edited

Thank you everyone for the additional detail.

The reason for my question is that this is one solution I'm thinking about to get an HF antenna into my shack. My "shack" is upstairs in a bedroom and my 2/70 antenna is up in the attic. I've already run coax from the attic to the room. With that already in place the "easy" way to get an HF antenna run is to put the transformer/feed in the attic and attach to existing coax. Then drop the wire out of an attic vent to my fence and run the whatever additional feet is required along the wooden fence based upon whatever length / band(s) antenna I decide to go with. But I've not run into another example of the feed line being at the high point. Before I invested into this experiment I thought I'm ask the collective minds here.

So far I've not found that this will not work but it's obviously an additional comprise like every antenna. I will check out the FB group and continue to research. Still on the fence (pun intended) on if it's worth going forward with this design or scrapping it and finding another solution. Research never ends.

If I do decide to go forward with this idea I'm looking at ants from myantennas.com and chameleon.com. Not cheap stuff but then I don't have to do any of the math. I'll also e-mail them after I do more research. Again, appreciate the collective knowledge!

Dan Pflugrath
 

Ryan,
I must run a stealth antenna at my QTH. The transformer is at the peak of my house at 20 about feet with the antenna wire 26 gauge out to some trees, no ground or counterpoise other than the coax lead in. about 67 feet of wire gives me 40, 20, 15 and 10 meters without a tuner and 30, 18 and 12 meters with a tuner. It is not optimum but I make contacts with it using QRP power. The higher the better for the antenna wire but you use what you have. Let me know if you find a better solution and let me know if you need help? I can help you build one if you want.

Let me know if you find a better solution. I am always looking for a better stealth antenna.

73,
Dan Pflugrath KA7GPP
dpflugrath@...
425-941-2339

-----Original Message-----
From: snovarc@groups.io [mailto:snovarc@groups.io] On Behalf Of Ryan - KJ7GIE
Sent: Thursday, June 27, 2019 10:46 PM
To: snovarc@groups.io
Subject: Re: [snovarc] End Fed Half Wave setup

[Edited Message Follows]

Thank you everyone for the additional detail.

The reason for my question is that this is one solution I'm thinking about to get an HF antenna into my shack. My "shack" is upstairs in a bedroom and my 2/70 antenna is up in the attic. I've already run coax from the attic to the room. With that already in place the "easy" way to get an HF antenna run is to put the transformer/feed in the attic and attach to existing coax. Then drop the wire out of an attic vent to my fence and run the whatever additional feet is required along the wooden fence based upon whatever length / band(s) antenna I decide to go with. But I've not run into another example of the feed line being at the high point. Before I invested into this experiment I thought I'm ask the collective minds here.

So far I've not found that this will not work but it's obviously an additional comprise like every antenna. I will check out the FB group and continue to research. Still on the fence (pun intended) on if it's worth going forward with this design or scrapping it and finding another solution. Research never ends.

If I do decide to go forward with this idea I'm looking at ants from myantennas.com and chameleon.com. Not cheap stuff but then I don't have to do any of the math. I'll also e-mail them after I do more research. Again, appreciate the collective knowledge!





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