One of my VOTER boards has decided to drop out of GPS lock when the transmitter is keyed up. Has been working fine for months.
The GPS antenna is a magnetic “puck” on the shed feeding a BG7TBL GPS. I’ve had one of these antennas die in the shack completely - plug it in and the GPS never gets lock. The UHF repeater antenna is about 30 feet vertically above it and I’ve never had an issue. Same GPS antenna on another site and that is only about 3 feet away from the TX antenna, but no issues there. Perhaps it’s water problems?
The second problem - perhaps coincidence, is that at least one of my transmitters lock on transmit. I did see this once on the bench but it never happened again. There was no input signal, and you could talk over the top of it. It never times out, and the RTCM board indicates PTT as 1. A reboot fixes the issue.
I've had the VHF transmitter knock my Trimble GPS out. Had to move the GPS antenna further away from the vhf antenna. In Trimble's software you could see a reduction in GPS signal on Tx, most would drop totally. Sometimes given the right conditions all would drop out.
Not sure if you can monitor the GPS signal strength on the Garmin puck, if so have a look and see if VHF tx makes a difference.
Jesse
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On Dec 28, 2017, at 7:30 PM, Hayden Honeywood <haydenph91@gmail.com> wrote:
One of my VOTER boards has decided to drop out of GPS lock when the transmitter is keyed up. Has been working fine for months.
The GPS antenna is a magnetic "puck" on the shed feeding a BG7TBL GPS. I've had one of these antennas die in the shack completely - plug it in and the GPS never gets lock. The UHF repeater antenna is about 30 feet vertically above it and I've never had an issue. Same GPS antenna on another site and that is only about 3 feet away from the TX antenna, but no issues there. Perhaps it's water problems?
The second problem - perhaps coincidence, is that at least one of my transmitters lock on transmit. I did see this once on the bench but it never happened again. There was no input signal, and you could talk over the top of it. It never times out, and the RTCM board indicates PTT as 1. A reboot fixes the issue.
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Thanks for the info. The GPS unit I have is the BG7TBL unit. When I said “GPS puck” I probably should have said GPS mouse active antenna that came with the BG7TBL unit (Little Black magnetic thing that has a SMA connector on the end of the coax).
I’m surprised that the GPS would be affected by the transmitter, but I suspect water may have gotten in somewhere causing it to go bad when it transmits now.
I can probably hook up directly to the serial output and measure signal and data to see what happens.
Still not sure why one of the Voter boards decided to lock on transmit though.
One of my VOTER boards has decided to drop out of GPS lock when the transmitter is keyed up. Has been working fine for months.
The GPS antenna is a magnetic “puck” on the shed feeding a BG7TBL GPS. I’ve had one of these antennas die in the shack completely - plug it in and the GPS never gets lock. The UHF repeater antenna is about 30 feet vertically above it and I’ve never had an issue. Same GPS antenna on another site and that is only about 3 feet away from the TX antenna, but no issues there. Perhaps it’s water problems?
The second problem - perhaps coincidence, is that at least one of my transmitters lock on transmit. I did see this once on the bench but it never happened again. There was no input signal, and you could talk over the top of it. It never times out, and the RTCM board indicates PTT as 1. A reboot fixes the issue.