Moxon Shapes

[Wineglass]

I have made and used a 2 element moxon for 11m for a few months now, i have modified it once since i have made it, i'm just curious do all moxon's have to be in either a rectangle or square shape??? at the moment my moxon is in a trapezoid shape i have not had any skip conditions to test the antenna in this position, has anyone else out there experimented with moxon aerials like this before?

 

[Wineglass]

I have made and used a 2 element moxon for 11m for a few months now, i have modified it once since i have made it, i'm just curious do all moxon's have to be in either a rectangle or square shape??? at the moment my moxon is in a trapezoid shape i have not had any skip conditions to test the antenna in this position, has anyone else out there experimented with moxon aerials like this before?

 

[wavrider]

I have not played with any moxons but a friend of mine has.
He built some for 6 meters and 2 meters.

He said the results were better than expected, good front to back and good forward gain. Broadbandwidth.

He used PVC to build the frame for the antenna.

Looking at the moxon sites for building them it pretty much needs to follow the shape it is designed for, any deviation from the design degrades the performance. Not saying it wont work, just that it won't work as it is designed to.

 

[CTStallion]

I believe the rectangular shape and spacing are what provide the two factors which make the Moxon superior to most other two element antennas, namely:

1. Superior F/B (front to back) ratio: for rejecting signals off the rear of the antenna

2. 50 ohm direct match for coaxial cable feed at the center of the driven element

There are many other 2 ele variations like the hex beam, M, W, X, etc, so a perfect rectangle is NOT an absolute, however, if not made to the MOXON dimensions, it will not perform like a MOXON.

 

[Wineglass]

On tuesday the 21/09 i had some really good conditions come in and the wineglass was put to work, in a matter of few hours i had several contacts from 224 division (Western Kirribati Islands) Several contacts with Hawaii aswell as America, I did hear Denmark come in for a few seconds with a 5/7 signal but the conditions dropped out as soon as it came in, I done some local testing, i compared it to my Inverted V, the test station was a mobile unit some 15kl'ms as the crow flies but the Tropical Rainforest mountain range was also inbetween us,. The inverted V produced a solid 5/5 signal to the test station i was recieving 2/3, the wineglass facing towards him, 7/9 and i was recieving 7/9 aswell, with it facing away from him i was producing a 4/5 5/5 signal and recieving at 2/3, The test station was using a Uniden Pro640e through 9ft stainless whip sitting on the side of the road going back to his place which is out of range, any further down the road and i would loose him as he goes down another side of the range.

 

[wavrider]

Glad to see you got it working and the results look promising. Great to have some conditions to test it out.

 

[Wineglass]

I am happy with it, but i think it still needs a little more tweaking, i am going to be pulling it down in the next fortnight and doing some changes to it, For example making the back reflector in between the two supports from 3.05 to 4 meter's, and bringing the driven element to 3.5 meter's in between the two front supports also adding longer insulators to go inbetween the driven elements and the reflector. we shall see how it handles skip and local after the next set of tweaking, fingers crossed please

 

[Wineglass]

It was 2 in the morning i couldn't get to sleep, my house mate was still awake so i got him to give me a hand pulling it down, i done what i needed to do done a test while it was on the ground SWR 1.6 on Channel 1 SWR 1.1 on Channel 40, put it back up in the air at about quarter past 5 in the morn. once it was up in the air time for more testing, still 1.6 on channel one but channel 40 has jumped up to 1.2, When i do another Test with a local station i will let you all know how it went