OK All U Beam Antenna Freaks.....

[hobie102]

I have decided to start the process of building a Moxon Beam for the house. I would like to use the ground plane of the metal roof to enhance it but I'm really not sure if that would be an actual benefit. Would that defeat the purpose of the beam directional antenna? I know they focus the transmission into a certain direction wherever they are pointed as well as increased rejection of unwanted signal coming in. If the metal roof would be a benefit, how and where should I place the antenna. My gut tells me to place it on the peak and isolated from the roof. I know higher the better. I could get it up about 25 feet. I need some science and suggestions to make a decision.

 

[w9cll]

Generally with a beam you do not need a ground plane under it as it get its ground form the other elements. For your metal roof you would want the antenna as far away from the roof as possible to prevent detuning.

 

[hobie102]

OK. That's exactly what I needed to know. Thanks much!

 

[hobie102]

Update

Looks like everything I'm reading is that a 3-5 beam yagi will out perform a Moxon. The Moxon is incredibly easy to build and I'm having problems finding info on a DIY build for the Yagi.

 

[M0GVZ]

A Moxon performs about the same as a 3 element beam. The advantage the Moxon has is it is a lot smaller, lighter weight and very easy to build yourself.

A 5 element beam will outperform a Moxon by maybe 3-4dBi but its a hell of a lot bigger, not as neighbour friendly and you need a bigger rotator to turn it.

 

[hobie102]

A Moxon performs about the same as a 3 element beam. The advantage the Moxon has is it is a lot smaller, lighter weight and very easy to build yourself.

A 5 element beam will outperform a Moxon by maybe 3-4dBi but its a hell of a lot bigger, not as neighbour friendly and you need a bigger rotator to turn it.

Got it! I was just looking at the Moxon Generator model it turned out for 10 meters and it's so easy and doable for a build. 3-4 dec' isn't enough for me to consider the Yagi the way I'm getting out now. With the moxon I believe I can really punch thru to western Europe based on the increased gain. I can get thru good now but the big stations run over the top of everybody not pushin big power. Just need that focused beam and just a tidy bit more. Just talked to Miami a few seconds ago. Busting thru no problem on the barefoot 980. Looks like I'm starting the build tomorrow. Would like to have it up by the beginning of the week. Gotta check the cable stash and see what I've got left. Cheers!

 

[357magnum]

Build me a MoonRaker 7 when you can fit it in Hobie!

Sent from my NB09 using Tapatalk

 

[vkrules]

Moxons a good place to start, remember to point it down this way once and a while.

 

[hobie102]

Build me a MoonRaker 7 when you can fit it in Hobie!

Sent from my NB09 using Tapatalk

Moxons a good place to start, remember to point it down this way once and a while.

OK, there you go again 357! Thanks a lot! Now I have to go and look at what a MoonRaker 7 is....Ur killin' me here! :headbang

I will definitely do that. I heard a station out of your area yesterday. Very faint. I screamed to the wife in disbelief. I know, I'm like a kid in a candy store with this stuff. :tongue:

 

[hobie102]

357, I just looked up the moonraker. Uh, yea, you're on your own with that one! Let me know how that goes would ya?:blink:

 

[M0GVZ]

With the moxon I believe I can really punch thru to western Europe based on the increased gain. I can get thru good now but the big stations run over the top of everybody not pushin big power.

During the CQ-WW-SSB 2012 contest I ran a Moxon on 10m at 22ft high with 100W of power. Had been trying to get to a Chinese station but no chance with the wall of Europe inbetween me and him. It was getting into the afternoon so I swung the beam around and pointed it south west to start working through South America. Scanning back through the 10m band I came across the Chinese station again. I could hear him a lot better as the wall of Europe was off the back of my beam 30dB down but you could still hear they were there. I put out a call and got straight through. 18,000 miles long path.

I'd love to see what the performance is on the 42ft pneumatic mast I now have but the Hexbeam is well and truly parked on that.

 

[w9cll]

During the CQ-WW-SSB 2012 contest I ran a Moxon on 10m at 22ft high with 100W of power. Had been trying to get to a Chinese station but no chance with the wall of Europe inbetween me and him. It was getting into the afternoon so I swung the beam around and pointed it south west to start working through South America. Scanning back through the 10m band I came across the Chinese station again. I could hear him a lot better as the wall of Europe was off the back of my beam 30dB down but you could still hear they were there. I put out a call and got straight through. 18,000 miles long path.

I'd love to see what the performance is on the 42ft pneumatic mast I now have but the Hexbeam is well and truly parked on that.

People forget about the long path.

 

[w9cll]

Hobie have a lookie here. The first one is the best option, small, light and easy to put together.

 

[wavrider]

Two element quad is a good antenna, I am running one now at 55 feet for 10 meters works great especially with the latest band opening.

Moxon will perform just as well if not better than the quad as the quad is most efficient at the design frequency, as you stray away from the design frequency it looses some performance. Not alot though.

The Moxon has a wide bandwidth, direct fed no matching network and uniform gain across the useable bandwidth. Hard to beat a simple wire moxon antenna for ease of build, cost vs performance.

 

[GnG8d]

I've had the 4 element Cubex up since 2011, but as wavrider says, they aren't very wide. I can comfortably cover 26.915-27.285 which gives me all of the popular AM frequencies, and I have a tube final so I can load up beyond that range, but it might not be the antenna for a serious freebander using a solid state final.