Long Distance Microwave Test September Update

The Image for this article is of a man named Gabor on top a tower installing the FECORE microwave transmitter for the August test. He heard about the test from Sandor and is excited to help FECORE establish a 307 km microwave link.

On August 17th and 18th two FECORE teams went to two locations in Hungary where Sandor and Gabor had installed our Ubiquiti AF-5 transceiver/antenna equipment. At one tower site was Sandor and Rob Durham. 307 km away Mike Cavanaugh, Stefan and Gabor were at the other tower. Everyone was excited to make the long distance microwave connection. To prevent interference in these tests I have not named the sites.

Ubiquiti had boasted that the AF-5 had made a 304 km link. So FECORE anticipated success in this attempt. Sandor at one antenna and Gabor at the other spent 6 hours adjusting both azimuth and tilt to establish a connection. The teams tested repeatedly for the possibility of obstructions or interference along the path. There seemed to be no problem of that nature. Despite hours of hard work over two days the August test did not establish a link.

During the live stream Sandor said they had tried every possible combination but nothing produced a link. After 6 hours of hard work on top of the tower Sandor was so exhausted he was shaking. The teams expended every effort and time ran out for this attempt. We were not sure what had gone wrong.

The very next day after the attempt FECORE began researching options. Mike wanted to know if we could purchase a more powerful system and have it delivered while he was still in Hungary. Although we couldn’t get it that quick FECORE members found that there were more powerful radios made specifically for long distances. The AF5 has a very large bandwidth ideal for a strong WiFi signal at  great distances but 300+ kilometers exceeded its ability.

It was discovered that there was a 304 km link that had been accomplished with a very different setup. In June of 2007 a team using Microtik radios and software established a link from Mount Amiata, Italy to a place near Tempio Pausania on the island of Sardinia. The dish antenna was custom made by a company named ASP 24. Both Microtik and ASP 24 are based in Latvia. Microtik manufactures radios and connection hardware. ASP 24 sells both Microtik and Ubiquiti products. The custom made dish antenna is estimated to have been 48 inches wide. They had a very slow data rate which means they had a very narrow bandwidth. This allows for a longer range for any given power output.

FECORE concluded that the AF5 equipment had too low of antenna gain and too small radio output to reach the 307 km distance. The AF5 radio is designed for very high data rates but is not well suited for long range connections. We found that Ubiquiti makes a much higher power radio and antennas with much higher gain.

The AF5 radio and antenna equipment FECORE used in August was rated at 47dBm effective isotropic radiated power or EIRP.

In the days after our August 17th and 18th attempt FECORE researched various options. One of our biggest concerns is that the test must be completed before the winter weather. Storms and freezing temperatures would make setting up and adjusting the antenna impossible. This means if we are going to make this connection this year the equipment must be readily available. We found a combination which is a great improvement which is also readily available.
FECORE has now purchased a Ubiquiti AF5X HD radio and an AF-5G34-S45 antenna. This is the AF 5X HD radio. It is rated as having 29dBm EIRP.

Below is the AF-5G34-S45 antenna. The signal gain is rated at 34 dBm.

With this combination our EIRP increases from 47 dBm to 63 dBm. That is 35.48 times more power than our previous rig. Expressed in watts the EIRP increases from 56.23 watts to 1995.26 watts. The test is being performed in Hungary and there is no output limitations in this band.

FECORE considered an even larger dish antenna but the towers will not support it and installing a huge dish would be far too dangerous. The AF-5G34-S45 dish will be dangerous enough to install.

The date for the new test is September 20th to 22nd. The equipment has been delivered already.

We thank all those people who worked so hard and donated both labor and money to make this possible.