The story of GB3JM begins in the U.S. with the N9IAA repeater network which covers Northwest Indiana and Chicago. As a part his professional duties maintaining a microwave network, Josh Marvel (M0WYP/N9JDM) also provided backend server support for Kevin Babich’s (N9IAA) AllStarLink server. At the beginning of his tenure, Josh was not a licensed amateur radio operator, but as a part of maintaining the server, learned about amateur radio operation. In April of 2017 received his Technician class licence and by January of 2018 passed his Extra class licence.
Almost immediately after passing his Extra, it became clear that he would have to move to the UK due to family health issues. In late 2018, the move was complete, and he settled in Leominster to be near to family and Woofferton transmitting station. Between February 2019 – May 2019, he successfully passed all three UK Amateur exams and achieved a Full licence.
Being 4000 miles away from the N9IAA repeater network presented quite a few problems, especially being able to monitor the quality of the RF output. Kevin suggested that he send Josh a Radio Thin Client Module (RTCM), a duplexer and a repeater and thus the concept of GB3JM was conceived.
Josh originally requested GB7LT (Leominster Town), but the ETCC manager suggested that since it was technically not a digital mode, he should select a GB3 callsign. After spending far too much time thinking about it, he decided on GB3JM (Josh Marvel) since there was always a chance of moving from Leominster to a surrounding village. In August of 2020, the ETCC and Ofcom approved the NoV for GB3JM.
Work began to assemble all the equipment for shipping, and it was then that Josh and Kevin realized the 70cm repeater we were planning on using couldn’t be used on the required frequencies. Kevin and Josh both began searching for alternatives. This, of course, was all happening at the height of COVID-19 so progress was slow in finding anything affordable.
In January of 2021, disaster struck, there was knock on the door from a Herefordshire Planning Enforcement Officer, down came all the antennas and with it the hopes of getting GB3JM operational. Fortunately, Josh and his family were able to find accommodation just outside of Leominster in the village of Luston with plenty of space for a proper antenna farm.
In March of 2021, Matt (G8XYJ) and Dave (G4OYX) Porter of the Hope Bagot Repeater Group approached Josh about performing some firmware updates on their existing Yaesu repeaters as Josh had previously updated the Herefordshire Amateur Radio Society’s GB3ZA and GB3HC repeaters. During the exchange of messages, Josh offered to setup and maintain a website for the repeater group, and in return Matt offered Josh the use of a Yaesu DR1-X repeater and membership of the Hope Bagot Repeater Group!
In May of 2021, Ofcom issued a NoV for GB3JM’s new location with no changes to the licence, and finally Kevin could tune the duplexer and ship all the equipment. In August of 2021, Josh received the equipment from the States, but social distancing/limiting remained in place.
In the Spring of 2021, Dave and Matt were busy moving all the other repeaters in the Hope Bagot Repeater Group to new locations. Unfortunately, in October, GB7VO, a DSTAR repeater at that time, suffered RX failure and the repeater designated for GB3JM was installed as a C4FM repeater in its place. Thanks to a generous donation in December, Dave was able to purchase two new DR2-X repeaters to replace the existing GB3VM and GB3VN DR1-X repeaters.
Finally in May of 2022, Josh was able to compile all the equipment, software, tools, sundries and most importantly find the time to assemble GB3JM. All equipment was mounted into an ex-MOD 6-unit 19” rack purchased from Phil Hoath (MW0XTK). The DR1-X, the original GB3VM, was mounted in the bottom 2-units. The RTCM (Radio Thin Client Module) and Celwave duplexer were mounted on a single unit tray. A 2-unit blank panel was converted to house custom 3d printed Anderson PowerPole 30-amp connector and CAT5e keystone mounts and a bulkhead N-connector for the antenna feed. A 240V 1-unit Fan tray was installed to supply additional cooling for the repeater. AllStarLink was installed in a virtualized VMware ESXi environment running on a dual processor HP Z820 server and registered as Node ID: 57188. The necessary firewall changes were made on a Cisco ISR router to allow connectivity to the AllStarLink network via a 400/400 Mbps fibre internet connection. Everything was tested as functional with a dummy load on the output. Finally, 7m of UltraFlex 7 feeder were run through the attic to the Diamond X50 antenna, supplied by Steve Holroyd (2E0HRE), mounted at 25 feet on the gable end of the house.
On Friday, June 3, 2022, at 19:10, after over two years of planning and work, GB3JM came online connected to the N9IAA repeater network, fulfilling its original intent and providing access to local amateur operators. Its coverage area is not particularly large, but it should cover Leominster and Ludlow nicely.
