RSP2 operating and/or Bias-T supply on over a long time
Posted: Wed Feb 21, 2018 2:12 am
At this stage it is only a suspicion that I have but....
I have an RSP2 that is being driven by a RPi3. The RSP2 is connected to two antenna: a discone on Port A and a QFH with LNA on Port B. (The goal is to capture the weather images from the NOAA and METEOR satellites - the discone when they are at a low angle and the QFH as they get above about 30 degrees).
The software in the RPi calculates the visibility of the satellites and then selects the appropriate antenna based on there being a single satellite visible and the angle above the horizon, or just the QFH if more than one satellite is visible. (I sample the frequencies from 137MHz to 138MHz, and then decode the specific satellite frequencies in software to allow for multiple visible satellites).
Originally I had the LNA powered all the time through the Bias-T and later I turned it on and off only when the QFH was in use.
Now to the problem: I was getting reasonable images most of the time (it was either good or nothing - not sure what conditions determined which outcome) when I started the program running but after a time (days?? week+??) it was as though the LNA was not working at all. This was the reason I tried to switch from the LNA on all the time to switching it on when required in case it was related to how long the LNA was running.
If I disconnected the RSP2 and then reconnected and restarted everything, the 'good' (i.e.with LNA apparently working) images came back.... for a while.
I need to do more testing to monitor the Bias-T voltage over a long period of time to make sure that it is actually being delivered and/or the LNA is actually working over a long period of time. I'm not getting any error codes back from the API as I interact with the RSP2.
Has anyone else seen this type of behaviour when the Bias-T has been running for a while and/or the RSP2 has been powered up for a number of days?
I would assume that this (powered up for days at a time) is a 'supported' operational mode.
Susan
I have an RSP2 that is being driven by a RPi3. The RSP2 is connected to two antenna: a discone on Port A and a QFH with LNA on Port B. (The goal is to capture the weather images from the NOAA and METEOR satellites - the discone when they are at a low angle and the QFH as they get above about 30 degrees).
The software in the RPi calculates the visibility of the satellites and then selects the appropriate antenna based on there being a single satellite visible and the angle above the horizon, or just the QFH if more than one satellite is visible. (I sample the frequencies from 137MHz to 138MHz, and then decode the specific satellite frequencies in software to allow for multiple visible satellites).
Originally I had the LNA powered all the time through the Bias-T and later I turned it on and off only when the QFH was in use.
Now to the problem: I was getting reasonable images most of the time (it was either good or nothing - not sure what conditions determined which outcome) when I started the program running but after a time (days?? week+??) it was as though the LNA was not working at all. This was the reason I tried to switch from the LNA on all the time to switching it on when required in case it was related to how long the LNA was running.
If I disconnected the RSP2 and then reconnected and restarted everything, the 'good' (i.e.with LNA apparently working) images came back.... for a while.
I need to do more testing to monitor the Bias-T voltage over a long period of time to make sure that it is actually being delivered and/or the LNA is actually working over a long period of time. I'm not getting any error codes back from the API as I interact with the RSP2.
Has anyone else seen this type of behaviour when the Bias-T has been running for a while and/or the RSP2 has been powered up for a number of days?
I would assume that this (powered up for days at a time) is a 'supported' operational mode.
Susan