I have a Motorola XPR8300 VHF Analog Repeater without an external power amplifier that all of a sudden has a lot of background interference or noise.
The repeater is on a mountain top however a long ways from any other transmitters. It is the only radio repeater at its location. It is used for a ski resort. The repeater has been operating well for the last several seasons. We have not had any issues with it until now and nothing significant has changed or is obviously broken.
Yesterday was the first day I was on location to obtain first hand observations and perform and troubleshooting. To me the repeater sounds like it could be feeding back into itself. Portable radios operating in close proximity to the repeater always sound good, loud and clear, strong signal and no background interference. However portable radios (multiple different makes and models) that are a further distance away produce a strong signal although there is a lot of background noise making their voice unreadable or at least very distorted. While dead keying a portable radio in an area that was known to experience interference when transmitting I noticed that the interference would increase in strength and pitch as if it was ramping up and then it would completely drop out. At that point the repeater was operating like it use to. It the signal was strong and sounded great from all locations on all radios. Upon immediately keying up the repeater again no interference was noted. If the repeater sat idle for a little bit and then was keyed up again the interference came back. When dead keying the repeater the interference was present and progressively increased in severity until it dropped out completely which took it about 10-15sec to complete.
For some additional information we are running a Telewave 4 Cavity Duplexer with a 4.5Mhz split and a StationMaster antenna. The interference seems to exist when operating off of both AC and DC power. The 3 second hang timer has a very clean and strong signal and the interference is never present during the repeater hang time.
Any troubleshooting ideas or suggestions on what maybe causing this interference/background noise?
The repeater is on a mountain top however a long ways from any other transmitters. It is the only radio repeater at its location. It is used for a ski resort. The repeater has been operating well for the last several seasons. We have not had any issues with it until now and nothing significant has changed or is obviously broken.
Yesterday was the first day I was on location to obtain first hand observations and perform and troubleshooting. To me the repeater sounds like it could be feeding back into itself. Portable radios operating in close proximity to the repeater always sound good, loud and clear, strong signal and no background interference. However portable radios (multiple different makes and models) that are a further distance away produce a strong signal although there is a lot of background noise making their voice unreadable or at least very distorted. While dead keying a portable radio in an area that was known to experience interference when transmitting I noticed that the interference would increase in strength and pitch as if it was ramping up and then it would completely drop out. At that point the repeater was operating like it use to. It the signal was strong and sounded great from all locations on all radios. Upon immediately keying up the repeater again no interference was noted. If the repeater sat idle for a little bit and then was keyed up again the interference came back. When dead keying the repeater the interference was present and progressively increased in severity until it dropped out completely which took it about 10-15sec to complete.
For some additional information we are running a Telewave 4 Cavity Duplexer with a 4.5Mhz split and a StationMaster antenna. The interference seems to exist when operating off of both AC and DC power. The 3 second hang timer has a very clean and strong signal and the interference is never present during the repeater hang time.
Any troubleshooting ideas or suggestions on what maybe causing this interference/background noise?