2 element 11 meter beam

[smoke blower]

I want to make a 2 element beam for 11 meters but I can't find any info on one just 3 elements on up. I have a Joe gun 8 element beam here that I bought but its way to large for what I need I got it at a good price I already have a set of moon raker beams up I just wanted something small I good add to a little radio I have in the house. I just need some measurements to make one.

[Bombero]

Hey Craig...

Google HB9CV 2 element Yagi for the 11M band.

There is all kinds of info and measurements as well as parts list.

Good Luck.

Bombero

[smoke blower]

Thanks I found the info

[443 Arizona]

you might consider a small 1/4w ant and just put some sort of reflector behind it if you want to get directional. as for gain, yuo wont have much at all with a 2 element.
but its all fun no matter what we build.
i was thinking of building a minature one this big>

[Bluerunner]

I built a two element quad beam. I used wire and bamboo and fed it with a 1/4 wave piece of RG59 for matching. I spaced it at only 24" between elements and tuned it for max rejection.

It gave me a good one S meter number improvement on transmit but it would put a +30 loudmouth way down in the grass when I turned my back to him. I could hear a pin drop in the direction I was facing with maybe half of all the noisy neighbors behind me blocked.

The varnished bamboo only lasted two years. That was two years more than all my energy and ambition lasted to build another one.

Just good cheap fun.

[MDYoungblood]

Are you planning to make it out of the Joe Gunn parts, if so you are already there, just use the reflector and driven element (gamma), the dimensions would be the same on that part of the antenna, you would have to play with the spacing of the mast to the driven element if you make it vertical polarized, wouldn't be a problem horizontal.

3's

Greg

[443 Arizona]

i did one a long time ago, it doesn't matter too much on the reflector spacing,, and if you go horizontal you will eliminate ALOT of the noise.
i also had a 1/4w coaxial balun on it, and also was able to use it as Half wave dipole. it had some directional properties but was weird because it acted like a longwire too.
hiegth is a factor. i had mine at 20 ' and believe it or not i talked to new zealand , ssb, barefoot at 3AM,, it was very directional off the end(not perpndicular)

alot of things get better when you get a wavelength above the ground.

so ya those things are fun as hell. part of mine is still laying on the roof from 25 yrs ago.

[MDYoungblood]

I agree with Bluerunner if your building a beam, a quad for one is a full wavelength compared to a yagi which is a 1/2 wavelength. They are quieter, wider banded, and very directional even in a 2 element configuration.

3's

Greg

[Buzzweiser]

Probably the best small 2 element beam would be a Moxon. There is a lot of information on them online. I know several guys here have built them including myself and they work really really well. Ham operators also swear by them. Check them out.

[smoke blower]

ok I have made the antenna what I need to know is do I need to make a rf choke for this and if so what is the best way to do that. I was going to just role coax in a circle but I need to know how many raps should I make for 11 meters and how big should the raps be like 4" round or bigger

[Bombero]

Hey...

So...I'm assuming that you have the antenna set up and the radio connected to it.

Is there RF that you need to choke?

Give your antenna a try first then decide if you need a choke.

If you determine you need one: [Please login or register to view this link]

Bombero

[MDYoungblood]

I would like to see what you have built so far, snap and post a couple pics. You can match a matching stub out of 75ohm coax cut to a 1/4 wavelength at frequency. If you have an antenna analyzer that will be helpful in tuning the stub. You have three choices on it's location, tee it off at the feedpoint, connect it inline with the feedpoint, or connect it past the feedpoint.

3's

Greg

[smoke blower]

I am having trouble with my computer I will try this weekend to post some pictures. I hate to say it but I'm a little confused about adjusting the stub and using 75 ohm. I was just going to take a piece of mini 8 coax and trim it back and put the shield on one side of the wire and the center core on the other side or can I take a coax connector out of an old amp and put it between the wire on the driven side. And what do I need to do to adjust the swr on it. I do have an MFJ Analizer

-- Wednesday, 12 August 2015, 19:48 PM --

I just need someone to maybe show me a drawing or something on how to fix up what I need to connect the coax to it. Sorry but I am somewhat confused on that part of the antenna. I made it out of 3/4 pcv and just tie straped a wire around the top of the pcv with the two couple inches that I need to put and insulator in it.

[Bluerunner]

What kind of antenna did you build?

What are the dimensions and spacing of the elements?

Pictures will help a lot.

[smoke blower]

Moxon 2 element beam 11 meters

[1206FL]

Good antenna for dxing. Should work well at about 20-30ft. If possible. They actually do well at 20ft. But I'm sure they would do well at 30ft as well. Not much more gain but maybe a bit between the 2 heights. Used to talk to a gent out of VT that ran one 20ft off the ground and it worked well. We held long qso's, me on my dipole at 25ft and him with the moxon. Signal never faded out bad enough to bother for 30-45 minute qso's. Anyway, the dx cycle is about to pick up a bit when it cools down so now is a good time to get them antennas up. I gotta replace my base antenna. Last one had a mishap. My fault totally. But at any rate have fun dxing with that moxon. What are your numbers again? I'll have to listen for you if you ever point it toward FL.

[MDYoungblood]

The 75ohm coax I suggested is to help match the impedance, using antenna analyzer set it at the frequency desired, (say if you want the middle of the band it will be 27.185, ch 19) and look at the impedance, it will be around 100 to 120ohm. Take a length of 75ohm coax about 7ft 9in and connect it the opposite way as the feeding 50ohm coax (center to the shield and shield to the center), the other end of the 75ohm coax is open, trim that end down until the analyzer reads 50ohm at the frequency. The 2 coaxes can be run together or you can roll the 75ohm into a loop. Seal up all the coaxes so water can't get into the shield and it's ready to go up in the air.

3's

Greg

[smoke blower]

My number is 221 in Va.

-- Saturday, 15 August 2015, 20:56 PM --

Here is a picture of the moxon I had to make it again out of aluminum the PVC didn't work to well. The problem I have though is the swr is like 5.0 how do I get that down I tried different things but i didn't have any luck.

-- Saturday, 15 August 2015, 20:57 PM --



-- Saturday, 15 August 2015, 20:58 PM --



-- Saturday, 15 August 2015, 20:59 PM --



-- Saturday, 15 August 2015, 21:02 PM --



-- Saturday, 15 August 2015, 21:04 PM --

I have a gamma match could I use that on the drive element to use to adjust the SWR

-- Saturday, 15 August 2015, 21:11 PM --

I was wondering could I remove the wire on each end and like I said just use a gamma match to get the swr set I want it to have good rejection I want the person behind me to not be able to hear me only in the direction I'm pointing . I hope I can get this to work.

-- Saturday, 15 August 2015, 21:52 PM --

On I forgot the driven element has a piece of pcv pipe in the middle so I have the center core of the coax going to one side of the driven element and the shield going to the other side don't know if that was right or not. I would love to just use a gamma match with it maybe it would be easier to set the SWR's

[231]

I want to make a 2 element beam for 11 meters but I can't find any info on one just 3 elements on up. I have a Joe gun 8 element beam here that I bought but its way to large for what I need I got it at a good price I already have a set of moon raker beams up I just wanted something small I good add to a little radio I have in the house. I just need some measurements to make one.

Build a Moxon. The F/B and F/S ratio is better than many yagi designs with more director elements. Doesn't have a huge forward gain but not bad either. The back door is well worth it. I've built several of them over the years and by far they are one of my favorite beams.

Google moxonantennaproject dot com and you'll find a free tool that will give you the measurements.

Good luck

231

[231]

My number is 221 in Va.

-- Saturday, 15 August 2015, 20:56 PM --

Here is a picture of the moxon I had to make it again out of aluminum the PVC didn't work to well. The problem I have though is the swr is like 5.0 how do I get that down I tried different things but i didn't have any luck.

-- Saturday, 15 August 2015, 21:04 PM --

I have a gamma match could I use that on the drive element to use to adjust the SWR

-- Saturday, 15 August 2015, 21:11 PM --

I was wondering could I remove the wire on each end and like I said just use a gamma match to get the swr set I want it to have good rejection I want the person behind me to not be able to hear me only in the direction I'm pointing . I hope I can get this to work.

-- Saturday, 15 August 2015, 21:52 PM --

On I forgot the driven element has a piece of pcv pipe in the middle so I have the center core of the coax going to one side of the driven element and the shield going to the other side don't know if that was right or not. I would love to just use a gamma match with it maybe it would be easier to set the SWR's

Dump the gamma match. Either cut the driven element in half and insulate the elements from the metal boom or use copper tubing from your local hardware store so you don't destroy the element you have.

The driven element needs to be fed like a dipole. After all, that's all the driven element is on a yagi is a dipole. Fed like a dipole no matching network will be needed...although it's a good idea to do a coaxial choke to help keep CMC in check. Some will use a 1:1 balun but it's really not necessary if you simply do a coaxial choke and feed the driven element like a dipole.

Good luck.

231

[smoke blower]

That is what I made was a moxon and the driven element is insulated from the rest and the measurements are exactly what it supposed to be but the SWR is like 5.0 I need to know what to do to get the swr down everything is made correctly.

-- Thursday, 20 August 2015, 17:38 PM --

Here is the driven element it is insulated and the coax center core goes to the left and the shield goes to the right.

-- Thursday, 20 August 2015, 17:39 PM --



-- Thursday, 20 August 2015, 18:53 PM --

Could someone please give me an idea on how to get the swrs down or what I have might of done wrong I would love to finish this or if I can't get it straight I will just tear it all apart sorry I can't figure out where to go from here

[MDYoungblood]

Nice pics, good to see you figured out how to post them. The last couple are interesting, looking at the coax both the center and the shield should be equal length and go straight to the elements. Where the coax splits is where the element length starts, that part of the coax radiates. The coax should be secured (taped) to the boom at that point to the mast and down. The reflector side of the antenna needs to be insulated from the boom also but not split like the driven element. Now going from tubing to wire changes dimensions so you have a lot of playing to do to get that part right. Make yourself a stand to get it in the air, 7 to 10 ft.
What does the antenna analyzer say the R and X values are and what is the frequency it's working at now?


3's

Greg

[1206FL]

I've heard guys that have built them say to make a plate to mount the mast pipe to out of wood. It supposedly insulates the antenna from the mast. Not sure if it helps or not and also like MD pointed out, shorten both your inner and other conductors to a minimum length and attach to feedpoint. Make sure they are equal lengths. Google some photos of them and maybe some ideas will pop into your head as well. My pal runs one up in VT and when conditions are right we can hold an hour long qso no problem. Me on a dipole at 25ft and him with a moxon 20ft off ground. He built his mast from 2x4's. And one out of 2" schedule 40 pvc conduit as well for mast. Used driveway side markers and some 1" pvc conduit for the X. Made a wood plate as well. This is where his feedpoint was. At any rate hope you get it resolved. Seems like MD has placed you on the right there. Lower antenna to at least 10ft or less. You may have some reactance but it will go away once up in the air. Tune it as close to R=50 and X=0 at cut freq. check swr. When done put it up to 20-30ft and you will be good to go. JMO. Good luck, be safe and get er done!!

[smoke blower]

OK great I now know 2 problems the coax center core and shield are not the same length and the reflector is not separated from the boom either. I will mess with it more this weekend.

-- Friday, 21 August 2015, 5:54 AM --

Oh and I do know if I go up in the 28to 29 mhz the swrs are like 1.3

[MDYoungblood]

Oh and I do know if I go up in the 28to 29 mhz the swrs are like 1.3

This means the driven element is too short which in turn means the reflector is too. If you have some extra tubing in the element try spreading them out about an inch on both sides (all 4) then take another reading with the analyzer.

3's

Greg