WT4RA and wt4en Repeaters
The development and operation of the WT4RA repeater system has been one of the major projects of the club during the past 25 years. This seems like a good time to review the history of the repeater system, so in the discussion below and in the four pictures that follow the discussion, I’m providing a somewhat brief history of our repeater.
The first picture, taken in 2002, shows on the left side the original Motorola equipment cabinet that was used to initially mount the Maggiore model R-1 repeater, CAT 1000 controller (which included autopatch, digital voice recorder, and audio delay features), and Henry Radio C-130 amplifier. In this picture the cabinet is sitting on our red spare parts locker which is still in use today. The middle of the picture shows our equipment rack which was acquired from Richard, W4BUE, (ex WA4BUE) at a WTRA Tail-gate party which the club held at the Nike Park in Carrollton in 2002. The cabinet cost the club $10 and is still in use today. On the right side of the picture you will see the Wacom WP643 VHF bandpass-reject duplexer. Above the duplexer you will see a coil of coax. This is the antenna feed from the relatively new remote base antenna waiting for its supporting equipment to be installed.
The first picture, taken in 2002, shows on the left side the original Motorola equipment cabinet that was used to initially mount the Maggiore model R-1 repeater, CAT 1000 controller (which included autopatch, digital voice recorder, and audio delay features), and Henry Radio C-130 amplifier. In this picture the cabinet is sitting on our red spare parts locker which is still in use today. The middle of the picture shows our equipment rack which was acquired from Richard, W4BUE, (ex WA4BUE) at a WTRA Tail-gate party which the club held at the Nike Park in Carrollton in 2002. The cabinet cost the club $10 and is still in use today. On the right side of the picture you will see the Wacom WP643 VHF bandpass-reject duplexer. Above the duplexer you will see a coil of coax. This is the antenna feed from the relatively new remote base antenna waiting for its supporting equipment to be installed.
The second picture is a composite view of the repeater from 2010 and shows that the repeater now has a functioning Kenwood TM-701A remote base radio with Doug Hall RBI-1 interface, Diamond X-50A antenna at 150 feet, UHF packet node, RLS-1000 remote link switch, and a rack mounted computer supporting IRLP node 8373. IRLP allows “voice over IP” internet connection to other IRLP repeaters worldwide. The remote base radio was computer controlled allowing it to switch between FM voice communications and operation of the packet node (DTENND). An image is included showing locations of other repeaters that we can link to with the remote base radio.
The third picture is a composite view from 2018 showing lots of changes to the repeater. The Maggiore repeater, CAT 1000 controller, Remote Base TM-701A radio, Doug Hall Interface, and packet node are all gone. Yaesu Fusion DR-1X repeaters for VHF and UHF, Arcom RC-210 controller, Motorola T-1500 UHF Duplexer (donated by the Hampton Public Service Team), Kenwood TM-V71A remote base radio (operating on both VHF and UHF), and a rack mounted folding keyboard and monitor have been added. The computer has been upgraded and now, in addition to IRLP, includes EchoLink node 88373 (which expands “voice over IP” connection capabilities), and the computer now has improved ability to directly control the remote base radio. The remote base radio is now programmed to allow connection to 44 eastern/central VA and NC repeaters and to operate on 6 simplex frequencies. An image is included showing the approximate mobile coverage of the WT4RA VHF and UHF repeaters.
Our repeater now has one of the best omni-directional antenna systems of any repeater in the area. However, there were a lot of growing pains in reaching this point. The fourth picture provides a history of the antennas used with the repeater system and below is a discussion of the successes and failures we experienced with each antenna installation.
The first repeater antenna was a Cushcraft ADM-4DA antenna installed in 1996 and was located just above the 300 foot level. This worked really great to the west, north, and east, but had almost no coverage to the south as this direction was blocked by the tower. Communications between Isle of Wight and the Franklin area was difficult, but it was possible to talk to mobile stations mid-way up the Eastern Shore. If you look close in this picture you can see a ~16 inch pipe looking object between the feedline and the antenna. This was a matching device to allow the 50 ohm impedance antenna to work with the 75 ohm cable TV hardline that ran down the tower to the repeater. Within a couple of days of the antenna installation there was a direct lighting strike to the tower which resulted in a serious noise problem for all users of the tower. In the process of resolving this, a contractor that the county was using for communications work noticed that a new antenna had been installed on the tower and thought that this may be the source of the noise. The contractor then removed our antenna, without telling us, and found that the noise continued. Our antenna was re-installed upside-down and the noise source was eventually traced to the tower lighting system. We later found that following heavy and/or long periods of rain we got a lot of noise on the repeater and that this problem would usually last for weeks. It took us over a year to realize that the antenna was installed upside down and that the matching networks on each of the individual antennas were collecting and holding water which would eventually cause a short circuit. We would continue to periodically experience this problem until our next antenna change.
The second repeater antenna configuration was installed a few years later and resulted from Joe, WC4R, working with Cushcraft to resolve the tower shadow problem. They suggested that 3 of the 4 antennas be mounted directly to the tower legs with the 4 th antenna mounted to a bracket which would stand out from one side of the tower forming a square with the 4 antennas. At the same time a second set of 4 antennas was installed in the same manner. As it turned out the antennas were too close together due to the spacing of the tower legs and while we had some coverage in all directions there were lots of nulls in the pattern and overall coverage was poor.
All tower work for the first two installations was done by Britt Belyea, W4GSF. On the initial installation Britt was assisted by Jim Foust. During this installation Dominion Power also assisted by using one of their trucks and really a long rope (provided by Britt) to help pull the hardline up the tower. On the second (and very windy) antenna installation Britt was assisted by Gary Reid, W4NGR (then WA4DFJ). Also, during the second installation Britt needed to lower a bucket to retrieve parts from the ground crew. As a result of the high winds the bucket got stuck in the tower at the 125 foot level. Jarvis Hearn, (W4RGN, then W4VWH), who at that time was close to 70 years old, joined the tower crew and climbed up and unstuck the bucket. Britt also donated the hardline for the run between the repeater and the antenna, and the two associated matching networks. For his efforts Britt was awarded lifetime membership in the WTRA. Britt’s last contact with the club was in July 2013 when he gave us advice to help with our fourth antenna change discussed below. He became a silent key on September 10, 2013.
In 2001 a new Rohn-80 tower (400 feet tall) was installed and the old tower (also 400 feet tall) was removed. This provided the opportunity to try our third antenna configuration. Dick, W4RBH, conducted extensive research on tower based antenna installations, with some technical assistance from Don, N4DJ. This resulted in the installation two Cushcraft ADM-4DA antennas being mounted on opposite sides of the tower at the 304 to 324 foot level with one and one-eight wavelength spacing between the elements of the two antennas. The feed line from the repeater was connected to the two antennas using a phasing harness which was designed to match the two 50 ohm antennas to the 50 ohm feed line at 147.195 MHz. This worked great with an almost perfectly circular pattern and very low VSWR. During the installation process the original 75 ohm feed line was replaced with a 50 ohm one inch diameter hardline. The new tower installation also provided the opportunity to install a Diamond X50A antenna for the planned remote base radio. This antenna was installed on the west side of the tower at the 150 foot level and was connected using one inch hard line. All antennas and feed lines were installed on the new tower by a really hard working crew from Wolf Contracting. Our repeater antenna worked great for several years before our old noise problem returned. This time it was traced to the feed lines which ran to the antennas along the middle mounting bracket. It seems that red tail hawks found these brackets a great place to perch while looking for food and that their talons had shredded the jacket of the feed cable. We arranged for an Isle of Wight contractor who was working on the tower to re-insulate and protect the cables, solving the problem.
The fourth repeater antenna change was the result of Chris, W4VX, working some magic with Isle of Wight Emergency Services, where he arranged for the procurement of two Andrew DB-224E VHF antennas and made arrangements to have Atlantic Communications do the antenna removal and installation work. These antennas were installed over a 2-day period in July 2013. This resulted in the now 17 year old Cushcraft antennas being replaced with new commercial grade antennas which were mounted in the same configuration and spacing as the previous antennas. It was later found that this antenna configuration would work on the UHF band if we carefully selected our UHF transmit frequency to be near the 3 rd harmonic of the associated phasing harness. It was found that 442.825 MHz was available for our area and worked well with the existing antenna installation. A Comet CF-4160 VHF/UHF duplexer was installed at the repeater end, and this antenna now supports both the VHF and UHF repeaters.
There was one more noise problem which began in the 2016 area. This time when the tower lighting would switch form daytime white strobes to “reds” the repeater would sometimes experience noise for the remainder of the evening. The problem was traced to a lighting control box mounted near our antenna. Once this was identified as the noise source the tower owner corrected the problem.
The 1996 picture gives a good perspective of the ~21 foot antenna height. The 2001 and 2012 pictures were taken from the ground near the tower making the antennas appear much shorter than they really are.
The first repeater antenna was a Cushcraft ADM-4DA antenna installed in 1996 and was located just above the 300 foot level. This worked really great to the west, north, and east, but had almost no coverage to the south as this direction was blocked by the tower. Communications between Isle of Wight and the Franklin area was difficult, but it was possible to talk to mobile stations mid-way up the Eastern Shore. If you look close in this picture you can see a ~16 inch pipe looking object between the feedline and the antenna. This was a matching device to allow the 50 ohm impedance antenna to work with the 75 ohm cable TV hardline that ran down the tower to the repeater. Within a couple of days of the antenna installation there was a direct lighting strike to the tower which resulted in a serious noise problem for all users of the tower. In the process of resolving this, a contractor that the county was using for communications work noticed that a new antenna had been installed on the tower and thought that this may be the source of the noise. The contractor then removed our antenna, without telling us, and found that the noise continued. Our antenna was re-installed upside-down and the noise source was eventually traced to the tower lighting system. We later found that following heavy and/or long periods of rain we got a lot of noise on the repeater and that this problem would usually last for weeks. It took us over a year to realize that the antenna was installed upside down and that the matching networks on each of the individual antennas were collecting and holding water which would eventually cause a short circuit. We would continue to periodically experience this problem until our next antenna change.
The second repeater antenna configuration was installed a few years later and resulted from Joe, WC4R, working with Cushcraft to resolve the tower shadow problem. They suggested that 3 of the 4 antennas be mounted directly to the tower legs with the 4 th antenna mounted to a bracket which would stand out from one side of the tower forming a square with the 4 antennas. At the same time a second set of 4 antennas was installed in the same manner. As it turned out the antennas were too close together due to the spacing of the tower legs and while we had some coverage in all directions there were lots of nulls in the pattern and overall coverage was poor.
All tower work for the first two installations was done by Britt Belyea, W4GSF. On the initial installation Britt was assisted by Jim Foust. During this installation Dominion Power also assisted by using one of their trucks and really a long rope (provided by Britt) to help pull the hardline up the tower. On the second (and very windy) antenna installation Britt was assisted by Gary Reid, W4NGR (then WA4DFJ). Also, during the second installation Britt needed to lower a bucket to retrieve parts from the ground crew. As a result of the high winds the bucket got stuck in the tower at the 125 foot level. Jarvis Hearn, (W4RGN, then W4VWH), who at that time was close to 70 years old, joined the tower crew and climbed up and unstuck the bucket. Britt also donated the hardline for the run between the repeater and the antenna, and the two associated matching networks. For his efforts Britt was awarded lifetime membership in the WTRA. Britt’s last contact with the club was in July 2013 when he gave us advice to help with our fourth antenna change discussed below. He became a silent key on September 10, 2013.
In 2001 a new Rohn-80 tower (400 feet tall) was installed and the old tower (also 400 feet tall) was removed. This provided the opportunity to try our third antenna configuration. Dick, W4RBH, conducted extensive research on tower based antenna installations, with some technical assistance from Don, N4DJ. This resulted in the installation two Cushcraft ADM-4DA antennas being mounted on opposite sides of the tower at the 304 to 324 foot level with one and one-eight wavelength spacing between the elements of the two antennas. The feed line from the repeater was connected to the two antennas using a phasing harness which was designed to match the two 50 ohm antennas to the 50 ohm feed line at 147.195 MHz. This worked great with an almost perfectly circular pattern and very low VSWR. During the installation process the original 75 ohm feed line was replaced with a 50 ohm one inch diameter hardline. The new tower installation also provided the opportunity to install a Diamond X50A antenna for the planned remote base radio. This antenna was installed on the west side of the tower at the 150 foot level and was connected using one inch hard line. All antennas and feed lines were installed on the new tower by a really hard working crew from Wolf Contracting. Our repeater antenna worked great for several years before our old noise problem returned. This time it was traced to the feed lines which ran to the antennas along the middle mounting bracket. It seems that red tail hawks found these brackets a great place to perch while looking for food and that their talons had shredded the jacket of the feed cable. We arranged for an Isle of Wight contractor who was working on the tower to re-insulate and protect the cables, solving the problem.
The fourth repeater antenna change was the result of Chris, W4VX, working some magic with Isle of Wight Emergency Services, where he arranged for the procurement of two Andrew DB-224E VHF antennas and made arrangements to have Atlantic Communications do the antenna removal and installation work. These antennas were installed over a 2-day period in July 2013. This resulted in the now 17 year old Cushcraft antennas being replaced with new commercial grade antennas which were mounted in the same configuration and spacing as the previous antennas. It was later found that this antenna configuration would work on the UHF band if we carefully selected our UHF transmit frequency to be near the 3 rd harmonic of the associated phasing harness. It was found that 442.825 MHz was available for our area and worked well with the existing antenna installation. A Comet CF-4160 VHF/UHF duplexer was installed at the repeater end, and this antenna now supports both the VHF and UHF repeaters.
There was one more noise problem which began in the 2016 area. This time when the tower lighting would switch form daytime white strobes to “reds” the repeater would sometimes experience noise for the remainder of the evening. The problem was traced to a lighting control box mounted near our antenna. Once this was identified as the noise source the tower owner corrected the problem.
The 1996 picture gives a good perspective of the ~21 foot antenna height. The 2001 and 2012 pictures were taken from the ground near the tower making the antennas appear much shorter than they really are.
What a lot of changes from the club’s start in 1995! This was only possible because of the support received from Dominion Energy who funded the initial equipment purchase under the RACES portion of their Emergency Action Plan, Isle of Wight County Emergency Services who provided building, tower space, and internet access, along with funding for equipment replacements/upgrades, WTRA who purchased the initial antennas, mounting brackets, and funded some of the equipment upgrades, and the WTRA club members and other area hams that donated funds and a considerable amount of their time to make all of this happen, especially those club members that have served on the repeater committee – over the years these guys have solved many more hardware and software problems than I could possibility discuss in this brief summary.
The repeater system’s primary purpose is to enhance emergency communication between the Isle of Wight EOC and the Virginia EOC and between the Isle of Wight EOC and Isle of Wight Shelters. In addition it provides a communication path for the EOC’s of all southeastern Virginia cites and counties (which are also in what is now ARES/RACES District 5) to reach the Virginia EOC. The repeater has two secondary functions which are performed on a not to interfere with ARES/RACES communications basis. These are to support the National Weather Service SKYWARN program and to support communications for the Healthcare Emergency Amateur Radio Team (HEART).
73’s
Dick, W4RBH
WTRA Treasurer
Repeater Committee Chairman
The repeater system’s primary purpose is to enhance emergency communication between the Isle of Wight EOC and the Virginia EOC and between the Isle of Wight EOC and Isle of Wight Shelters. In addition it provides a communication path for the EOC’s of all southeastern Virginia cites and counties (which are also in what is now ARES/RACES District 5) to reach the Virginia EOC. The repeater has two secondary functions which are performed on a not to interfere with ARES/RACES communications basis. These are to support the National Weather Service SKYWARN program and to support communications for the Healthcare Emergency Amateur Radio Team (HEART).
73’s
Dick, W4RBH
WTRA Treasurer
Repeater Committee Chairman