Marty N8XPK and his assistant Joe completed replacement of the two 5.8 GHz data link dishes at Marty’s tower in a 200 foot high climb on a beautiful November 1st. These dishes were damaged in a somewhat unusual electrical storm in mid-October. The picture to the right shows one of the damaged radio units that was removed from service. Note the burn mark in the lower right corner of the case. The unit was completely disassembled to look for further signs of damage, but the circuit board surprisingly didn’t have obvious signs of damage. It was completely dead functionally.
The new units are in place, and we once again have a full strength signal back to N8CD’s house to deliver Internet to the repeater site. Allstar, Echolink, Newsline, and remote monitoring and administration are all delivered over this data link. Our signal strength is even better than before now.
Normally, radio equipment is installed at the base of the tower in a protected room, and feedline goes up the tower to antennas. Because of the incredible feedline losses at 5.8GHz, it isn’t practical to use conventional feedline to deliver the signal up the tower. Instead, many modern microwave communication systems put the radio up on the tower directly connected to the antenna. This completely removes feedline losses from the system. The microwave radios are then fed with CAT5e Ethernet cable instead of RF feedline. This approach makes the system much more efficient, but it also exposes the microwave radios to electrical surges higher than what they might see at the base of the tower.
The new dishes also now have lightning/surge suppressors installed at both the bottom and the top of the Ethernet cable that feeds them. Hopefully this will reduce the chances of damage in future electrical storms due to currents induced in the Ethernet cable that connects to the dishes.
Thanks to Marty N8XPK and his assistant Joe for their efforts in getting us ready for the long winter season!