Yagi internet antenna improvements

[amerrycan]

Aloha!

The only internet available to me on the side of this mountain is wireless, and the only company that offers it has only one antenna they use for their customers.

What they installed was a DMS Wireless Yagi antenna, model YA90012. Link for specs in PDF are HERE

This particular 896 - 960 MHz antenna has 9 elements and a gain of 12 dBi but I am wanting to boost this up a bit to improve our reception from the repeater that is about 15 miles away.

So without purchasing a new antenna will my reception improve by adding another 11 elements to the tip of this antenna or by building my own with 20 elements? would it be better to rebuild it out of copper instead of aluminum?

Any help is appreciated

 

[VEBill]

If a weak signal was the actual root cause of poor link performance, then an antenna with higher gain should help.

The modem probably has a status screen where, assuming it's not protected with an unknown password, you could confirm the actual signal strength. It would be worth researching the system and modem information. If you can confirm a good signal strength, then you've just saved yourself a lot of effort. If you can confirm it's weak, then you can approach the service provider with this info.

The service provider should have confirmed signal strength during installation; and they should be happy to install a better antenna if indicated.

If a better antenna in indicated, and the service provider refuses to assist (that would be strange), then purchase is probably the best option. Such antennas are available for about $30 and up price class on eBay (900 MHz Yagi).

The 900 MHz band is unlicensed and shared with older cordless telephones, wireless speakers, wireless microphones, baby monitors, intercoms, and who knows what else. Interference is therefore also a possibility.

There's no (real world) practical advantage to copper vs aluminum for antenna construction; not that anyone would notice.

 

[Higgler]

Arraying 2 or 4 is a better way to increase gain, if they are build identically.

 

[Higgler]

First try moving your antenna up and down by just a few inches, or a few feet. If you can borrow a Spectrum Analyzer and look at received power that will help. RF Bounce off the ground or buildings can really lower received power, or raise it too from multi-path.

 

[Comcokid]

Amateur radio books on antennas provide many articles on designing Yagi which can be useful for adding a few more elements to an existing Yagi. Generally, the elements further from the driven element are cut a little shorter. Make sure the pole supporting the antenna is at the rear, and not in the middle. More than one Yagi can be put side-by-side for more gain if you phase them together properly. Keep the orientation (polarization) of your antenna the same as the antenna you're linking to. That is, unless there is flat terrain or a lake in between your long path, in which case most of what you are receiving may be the remaining horizontal polarization after reflecting off the earth.

 

[Higgler]

I was instructed by my antenna professor in 1979 to propagate the name Yagi-Uda, or better Uda-Yagi. Uda was a Grad Student who did most of the work developing and perfecting this antenna. Yagi, his supervisor took most of the credit. Per Dr. AD Wunsch.