Beam Issue

[skyview]

I recently installed a 5 element 220 beam on the roof (well had help, I didn't/cant go up). To reduce torque on the mast, we mounted the antenna to the mast between the 3rd and 4th element, balancing nicely. But, the beam is performing rather poorly, the same but definitely not better than an omni. Did mounting between the 3rd and 4th element result in an issue in performance. Again, the beam works almost the same as an omni.

Thoughts.

Thanks.

 

[K4EET]

What is the antenna make and model? How did the instructions say to attach it to the mast?

 

[W3DMV]

Couple questions first:
is the beam mounted vertical or horizontal
and what material is the mast made of?

 

[K4EET]

the beam works almost the same as an omni

Something is definitely not right. Is it on a rotator or are you trying to direct your signal in a particular direction? With 5 elements, you should see a difference in coverage.

 

[wtp]

new coax ?

 

[alcahuete]

Couple questions first:
is the beam mounted vertical or horizontal
and what material is the mast made of?

This. Hopefully you mounted it for vertical polarization.

 

[skyview]

OK, so this is vertically polarized. Instructions made no mention of just how to mount. This is an Arrow 220 5S and is solid aluminum. Coax fairly new, and if I compare to a omni works equal, just not providing directionality.

 

[K4EET]

Must be end mounted…

 

[K4EET]

OK, so this is vertically polarized. Instructions made no mention of just how to mount. This is an Arrow 220 5S and is solid aluminum. Coax fairly new, and if I compare to a omni works equal, just not providing directionality.

I probably should have cited the URL to the instructions. Pages 1, 4, and 5 have details on the end mounting hardware.

https://www.arrowantennas.com/inst/220-5S.pdf

 

[skyview]

Ha, that sure says end mount! I dont recall that diagram but maybe I was supposed to look online, which I didnt. Will have to arrange for someone to get up and fix mount. Thanks! I know we were completely confused on the mounting bracket itself, unable to figure out instructions and I fear thats where all our attention was.

 

[Golay]

Yeah like K4EET has pointed out, needs to be end mounted.
Right now you have a six element beam with one element WAY out of resonance.

 

[skyview]

Hopefully week after 4th of July can get it adjusted, bad thing is mount is so hard to work versus the normal ubolt. Still someone on the roof so hopefully can adjust. Ill report back if get end mounted, no doubt big difference.
Thanks

 

[K4EET]

Still someone on the roof so hopefully can adjust. Ill report back if get end mounted, no doubt big difference.

Once you have the antenna end-mounted, what will you be using to adjust the Gamma Match (Page 3 of the instructions)? Will you be using an Antenna Analyzer or transmitting with a radio (use low power) and a VHF SWR/Wattmeter? When adjusting the Gamma Match, first make sure the beam is pointed where you want it to be pointed (if you are not using a rotator). Then when checking the SWR, make sure the person on the roof is at least 10 feet away from the antenna while making the measurement. That is to avoid any interaction between the person and the antenna. Adjust the Gamma Match in small increments to find the best SWR for either your primary frequency of interest or the middle of the range that you will be transmitting on.

Coax fairly new

By the way, what is the nomenclature of the coax that you are using and the run distance to your radio? Depending on the distance, 220 MHz can have a significant amount of loss with certain coax.

You are close to having a great antenna system. Keep us posted on what you are doing and how the end result turns out.

 

[BabaYaga60]

Must be end mounted…

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