Last Updated on May 29, 2021 by tkp
The signal interruptions that we have experienced starting in the first week of May 2021 are not from any audio components, or from the studio side of the network. They come from somewhere after the transmitter side microwave dish. Beyond that the current diagnosis is given below. A trip up to Table Mt was needed.
The next day, we went up to the Transmitter site – not an easy feat considering that the Winter closure of the roads was still in place. For this reason, we had to hike about 1.5 miles with approximately 1000 feet of elevation gain.
As the issue was determined from below to be in the network following the microwave dish, all of the network cables were checked along with replacement of the internet switch that follows the dish. This seemed to fix the problem for awhile, however approximately 18 hours later, the signal dropped out again. This indicates that the electronics of the microwave dish will need to be replaced as that is the only other component in the signal path that was not replaced……….
Update 5/11/21: According to the log files, the on-the-air signal has not gone out for more than a few minutes over the past 4 days. However, the problem is not “fixed” and microwave dish electronics still need to be replaced and are on order…..
Update 5/13/21: According to the log files, the on-the-air signal has been out most of the time since approximately 12:30 PM 5/12. We are still waiting to receive parts to hopefully rectify the problem. When those are received, further actions at Table Mt will be taken….. in the mean time, expect the signal to be up sometimes, and down others…
Update 5/15/21: The main problem is that an animal of some sort – likely a rodent – chewed into the line from the microwave dish. This was not seen previously as it was assumed the issue was inside of the transmitter shack and this could only be seen from the outside. The cable could not be repaired using what we had with us, but we did have another cable that was long enough. This cable will however need to be replaced as it is not meant for exterior use. Because we had some replacement parts for the microwave electronics, we put those in. There still are some adjustments that need to be made, which should be possible from the studio.
Update 5/16/21: The on-the-air signal has been dropping out periodically since late yesterday, but this afternoon those dropouts are occurring at an average frequency of once every 30 minutes. It should be noted that, historically, from my observations, the FM signal has dropped out for brief times at least once every couple of hours. I got some ideas from Dan Sullivan regarding things that could be done to improve this, and will try these over the next few days – any changes need to be made with caution as there is always the possibility that the wrong move could bring the broadcast signal back down to zero……
Update 5/22/21 – 5/23/21: I spent several hours at Table Mt on Saturday, where it was approximately 30 degrees cooler than down here in the valley (OK if the temp is 90 here, but not OK if it is 70). A number of things have been tried to remedy the dropouts – in part these have involved replacing the temporary cable to the microwave dish with a proper and permanent one, and also updating all of the firmware to current versions.The situation is not remedied, but it has improved. Below is a graph showing the dropout time in mins (Y axis) vs date (X axis); the average dropout frequency has decreased approximately 3x from yesterday (i.e. it is better, but dropouts are still there):
Update 5/29/21: Quite a few things have been tried this week, but one change seems to have solved the main symptom of on-the-air dropouts without actually solving the underlying problem. The settings on the Barix encoder/decoders were changed in various ways and it was found that one combination resulted in the dropouts – of the type we were experiencing – disappearing. They have not recurred since 5:20 PM Thursday May 27. This is actually the longest period of time these type of dropouts have not occurred under any circumstances I have seen, so it is likely the Barix boxes were never really set up correctly. The underlying problem is still there, and will need to be resolved at some point. The disappearance of the dropouts, as recorded in the Barix log, is shown below; vertical blue lines indicate times dropouts occurred:
