Hello fellow HAMs! This is BG5FWP, a HAM from a small county in Ningbo, and I'd like to ask for your advice on two-transmitter repeater systems.
Our repeater was granted a license in early June, with the callsign BR5BE. It was built by several local amateur radio operators in Ningbo, and we are very grateful for their help. This allows us to have an amateur radio repeater in our small county, making it easier to communicate.
Our repeater consists of two Veno N7500 chassis, and I will briefly explain its operation (see Figure 1).
First, our repeater is located on a mountain. The two units are separated by approximately 100 meters, and the receiver is positioned higher than the transmitter. Each unit has its own WiFi router and mobile phone. The receiver receives the signal, and the receiver's mobile phone connects to the radio via Bluetooth to synchronize and forward the recording to the transmitter's mobile phone. The recording on the transmitter's mobile phone is then transferred to the transmitting radio via Bluetooth.
This creates a significant drawback: when the network base station stops operating, our repeater "fails," for example, before Typhoon Bawi made landfall, a base station at the foot of the mountain went down. This resulted in intermittent WiFi signal (poor signal on the mountain), making normal communication impossible, and causing audio forwarding to be unreliable.
A few days ago, while reviewing the N7500 manual, I inadvertently came across the definition of the N7500 handheld's antenna port (see Figure 2). This made me wonder if it was possible to connect it via a cable. So, this afternoon, we went up the mountain and brought a 100-meter long Ethernet cable (a simplified diagram is shown in Figure 3). We decided to connect the GND of both machines together, with the receiver's SQL connected to the transmitter's PTT, and the receiver's AFOUT connected to the transmitter's MIC. After testing, we found that it was indeed disconnecting from the network (breaking the connection), but all we heard were static noises, making communication impossible. When we disconnected the AFOUT-MIC cable, the sound disappeared, but we still couldn't establish a normal connection.
I humbly request the support and assistance of all esteemed colleagues.😭
(Figure 1)
(Figure 2)
(Figure 3)
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