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Author Topic: EARCH 40-6m end fed antenna  (Read 9558 times)

AC0AX

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EARCH 40-6m end fed antenna
« on: December 13, 2013, 04:50:09 PM »
Has anyone built one of these? I'm thinking of building one to go with my qrp rig.

cockpitbob

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Re: EARCH 40-6m end fed antenna
« Reply #1 on: December 13, 2013, 05:09:13 PM »
It depends.  I'm a real fan of half-wave end feds.  You need an end-fed type tuner, and the wire has to be a half wave, or multiple of that.  I use a 63' long wire and a SOTA tuner and that gets me 40M, 20M and 15M with the same wire and just minor adjustment of my SOTA tuner.  For 30M or the other shorter bands the wire has to be 1/2 wave.  The SOTA tuner won't do 10M though.

The other option is just a random length long wire and a tuner for that.  The Switched Long Wire Tuner is a nice choice, or any traditional 2 cap and 1 inductor tuner should work.

gil

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Re: EARCH 40-6m end fed antenna
« Reply #2 on: December 13, 2013, 05:52:16 PM »
Yep, I have. Works fine but you do need a tuner.
I love end-feds. They are the easiest to setup in the field.
With a slingshot, fishing line and weight, you can reach very high branches..

Gil.

AC0AX

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Re: EARCH 40-6m end fed antenna
« Reply #3 on: December 13, 2013, 05:59:27 PM »
Did you build yours Gil? I'm trying to figure out what size enclosure to use.

gil

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Re: EARCH 40-6m end fed antenna
« Reply #4 on: December 13, 2013, 06:09:07 PM »
Quote
Did you build yours Gil? I'm trying to figure out what size enclosure to use.

Yes, I'll try to find it when I get home and post a photo. I used a small plastic case from Radio Shack.

Gil.

cockpitbob

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Re: EARCH 40-6m end fed antenna
« Reply #5 on: December 13, 2013, 06:51:26 PM »
Hal,

Consider building the SOTA tuner kit ($30).  Unless you have a well stocked junk box you really don't save much buying all the pieces yourself.

I'm not certain it will tune an end fed 1/2 wave, but here's a kit for a traditional 2-cap, 1-inductor QRP tuner for $21 shipped.  I have it and though I haven't built it yet, it looks quite good.  More than worth the parts.  (Be sure to read the description.  It's hysterical.)
« Last Edit: December 13, 2013, 06:53:19 PM by cockpitbob »

AC0AX

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Re: EARCH 40-6m end fed antenna
« Reply #6 on: December 13, 2013, 07:02:23 PM »
I got one of them already. It does really look good, especially for the price.

AC0AX

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Re: EARCH 40-6m end fed antenna
« Reply #7 on: September 17, 2014, 12:56:40 PM »
I finally got around to building the antenna. Honestly I'm quite happy with it. I also finally got around to get a station back together. Anyhow back to the antenna, with my z-100plus auto tuner it will tune 40 thru 10 with no problems.  Also compared to when I had a station  last my noise problem is gone so its a win win for me.

Lamewolf

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Re: EARCH 40-6m end fed antenna
« Reply #8 on: October 06, 2014, 03:44:38 PM »
Yep, I have. Works fine but you do need a tuner.
I love end-feds. They are the easiest to setup in the field.
With a slingshot, fishing line and weight, you can reach very high branches..

Gil.

Gil, gang,
If they hade designed the UnUn properly then you would not need a tuner with it.  They use a mix 2 powdered iron core in their UnUn and you can wind a better one using either a mix 61 or 43 ferrite core in a 9:I transformer design that will match an actual endfed halfwave length wire to 50 ohms without a tuner.  Not sure about the specs on the mix 61 cores, but for an FT114-43 you wind 30 turns of wire with one end of the turns going to ground and the other end going to the antenna and then wind 10 turns of wire over top of the cold end of the 30 turns with one end to ground and the other end to the center of the coax feedline.  But you must fine tune the length of the wire to get a perfect match - around 63' to 67' for 40 meters depending on location and configuration.

gil

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Re: EARCH 40-6m end fed antenna
« Reply #9 on: October 06, 2014, 04:00:12 PM »
Hi, I am sure that would work, I haven't tried. The goal of this antenna is to be multi-band, so a tuner is required for that..

Gil.

Lamewolf

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Re: EARCH 40-6m end fed antenna
« Reply #10 on: October 06, 2014, 04:35:18 PM »
Hi, I am sure that would work, I haven't tried. The goal of this antenna is to be multi-band, so a tuner is required for that..

Gil.

Yeah, I know and that type of antenna works great with my Icom 703 and its built in autotuner.  The autotuner in the Icom 703 can tune up to 10:1 swr (mine has handled a 12:1).

Lamewolf

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Re: EARCH 40-6m end fed antenna
« Reply #11 on: December 04, 2014, 10:45:12 AM »
I built the 9:1 unun last weekend and got it mounted in a box, this weekend I will be cutting various lengths of wires to use with it.  I have read that there are certain non resonant lengths that gives a low swr on several bands without a tuner.  We be interesting to play with for sure !

cockpitbob

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Re: EARCH 40-6m end fed antenna
« Reply #12 on: December 04, 2014, 01:46:41 PM »
Just stay away from lengths that are 1/2 wave, or a multiple.  They'll look like a very high impedance that the tuner won't be able to handle.  26' and 53' are popular lengths for an end fed with a 9:1 unun.

Lamewolf

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Re: EARCH 40-6m end fed antenna
« Reply #13 on: December 04, 2014, 03:05:45 PM »
Just stay away from lengths that are 1/2 wave, or a multiple.  They'll look like a very high impedance that the tuner won't be able to handle.  26' and 53' are popular lengths for an end fed with a 9:1 unun.

Yeah, those were 2 of the lengths listed, but there are numerous lengths list that were much longer and even worked down on 160 meters.  I have them all written down somewhere here.  If I can find them, I'll post them here.

Lamewolf

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Re: EARCH 40-6m end fed antenna
« Reply #14 on: December 05, 2014, 07:30:51 AM »
Here are some good lengths of wire to use with the 9:1 unun for multiband use that I found in an article about this type of antenna:

6 to 160 meters: 53', 59', 72', 124.5', 162', and 175' (53' and 124.5' supposedly the best)  Personally I don't see how 53' could work well at 160 meters, and 124.5' is very close to a half wave on 80 meters !

6 to 80 meters: 36', 44', 53' 59'

6 to 40 meters: 24.5', 29.5', 36'

All lengths are in feet, to convert to meters, divide by 3.281

These lengths are supposed to give low swr without a tuner but I have not tried them myself, they are only lengths that are not a half wave or a multiple of a  half wave which supposedly keeps the impedance in a manageable range.

Radio Preppers

Re: EARCH 40-6m end fed antenna
« Reply #14 on: December 05, 2014, 07:30:51 AM »