12dbsinad
Member
- Joined
- Mar 15, 2010
- Messages
- 1,953
I am interested in starting a discussion about bi-directional amplifiers and interference (not related to bad installation practices).
BDA's are becoming common, and a big push with the NFPA. On lower frequency systems, 150-512 Mhz, wideband noise (RFI) is becoming a common issue with land mobile radio. This issue is caused by newer electronics, LED lights, switching power supplies and so on and so fourth. It is to the point that degradation in these bands is a major issue in handheld and mobile radios operating in new vehicles because of "noise".
I have been aware of some situations in the VHF band with use of BDA's that are amplifying this wideband RFI out of the building and to the system receivers creating a very high noise floor and severely degraded performance of the system. A proper installation of the system may be OK at the time of installation, but may change with the addition of "whatever" in the building that cause severe garbage that is becoming the norm. Of course, the more BDA's with this, the more the problem. A little bit of noise (and RF power) into a high gain antenna pointed at the system receiver(s) is of concern.
BDA's are becoming common, and a big push with the NFPA. On lower frequency systems, 150-512 Mhz, wideband noise (RFI) is becoming a common issue with land mobile radio. This issue is caused by newer electronics, LED lights, switching power supplies and so on and so fourth. It is to the point that degradation in these bands is a major issue in handheld and mobile radios operating in new vehicles because of "noise".
I have been aware of some situations in the VHF band with use of BDA's that are amplifying this wideband RFI out of the building and to the system receivers creating a very high noise floor and severely degraded performance of the system. A proper installation of the system may be OK at the time of installation, but may change with the addition of "whatever" in the building that cause severe garbage that is becoming the norm. Of course, the more BDA's with this, the more the problem. A little bit of noise (and RF power) into a high gain antenna pointed at the system receiver(s) is of concern.