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Full Version: Radome position on radar arch
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Hi, just got an RD418HD and am wondering if i need a pedestal on my arch or not. I have it mounted at the moment, and just wondering if it is high enough in relation to a Glomex tv antenna, a standard VHF antenna, and a Ubiqity Bullet wifi antenna that ive mounted. Will those items cause interference on a height level? or just distance from the radome? or does it not matter if they are not going to be operated simultaneously? ie.....wont be using the wifi while underway, only at marina, where I then wont be using the radar?


If installed within the beam of a radar antenna, the NMEA Installation Standard calls for following minimum distances from other antennas:
- VHF antenna - 2 ft
- SSB antenna - 3 ft
- Cell antenna - 2 ft
- Sat TV antenna - 3ft

Raymarine's guidelines call for install radar antennas as least 1m from other antennas.
So, if the beam (12.5deg down) clears the top of the analog tv antenna, then theres no issue? also, if thats the case....does the tv antenna still need to be 1m from the radome? We are talking about an arch on a Chaparral 270 Signature....not a whole ton of room up there.


Generally, if the antenna is not within the beam of the antenna then the antenna spacing would not apply. Before committing to not using a pedestal, I would recommend placing the antenna in its intended location with temporary power/communications connections and then test the performance of the TV reception for interference. It may be advisable to perform such testing with the radome elevated to the height of a pedestal as well.
Ok, so I should notice interference with both the tv and wifi antenna in that scenario, rather than seeing anything on the radar display? Is there any risk of frying the tv and or wifi antenna while the radar is transmitting?

Q1: Should I notice interference with both the tv and wifi antenna in that scenario, rather than seeing anything on the radar display?
A1: Indeed, positioning the radome too close to the specified antennas may result in interference with the TV and Wi-Fi, rather than adversely affecting the performance/life of the radome. The reason for specifying minimum distances from other antennas is to minimize the risk of RF energy from a transmitting antenna causing damage to the receivers devices which have been connected to nearby antennas. The safest solution is to provide the recommended minimum spacing and/or provide vertical separation.
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