Lack of Sun Spots or ?

[thelight1530]

We are a 2500 watt Daytimer that is 20 miles outside of a city that we need to reach. From about 6am until 8:00am and from about 5:30pm until we lower power we are encountering interference from a 5,000 Daytimer in a city that is over 250 miles away. Here is my question: is this being caused by the lack of sun spot activity? If not, then what could it be? We have a brand new transmitter and an Optimod 9400.
Any information would be greatly appreciated.
Thanks!

 

[DanStrassberg]

We are a 2500 watt Daytimer that is 20 miles outside of a city that we need to reach. From about 6am until 8:00am and from about 5:30pm until we lower power we are encountering interference from a 5,000 Daytimer in a city that is over 250 miles away.

Is the interfering station supposed to operate with different facilities (lower power, different directional pattern) during critical hours? The times when you are receiving interference sppear to coincide with CH. As a class D AM, your station is not protected from daytime-skywave interference during CH but you might have been getting such protection if the interfering station had been changing its operating mode during CH to protect a co-channel Class A AM. You might now be receiving interference because the station in question has stopped changing its operation during CH (thereby no longer operating in compliance with the terms of its license). If that is the case, I don't know how much weight a complaint from you to the FCC would carry, because the protection you were receiving was incidental to the protection of the Class A station. The complaint that the FCC would be most likely to heed would come from the Class A station, which presumably is now receiving interference from which it is supposed to be protected. The Class A station might easily be unaware of the situation. So you certainly should bring it to their attention. Call the CE if they have one or the contract engineer if they have no CE on the payroll.

 

[DanStrassberg]

We are a 2500 watt Daytimer that is 20 miles outside of a city that we need to reach. From about 6am until 8:00am and from about 5:30pm until we lower power we are encountering interference from a 5,000 Daytimer in a city that is over 250 miles away.

I'm pretty sure that I've identified your station and I have found a 5 kW daytimer that kind of fits your description of the interfering station. That station is indeed licensed to use lower power during CH, so it might be the culprit if it is failing to reduce its power during CH as it is supposed to be doing. Most likely, the problem is a failure in this station's automation system, but the problem could be willful operation outside of the station's terms of license. Some stations have even been known to cut their carrier at the time of a required operational change to simulate the change without actually making any change. Unless you are sure that the station is blameless, you need to get hold of a field-strength meter and probably make a trip to a place inside the suspected station's daytime groundwave coverage area where you can make some measurements at the scheduled time of the CH power cut or power increase. The signal strength should drop by a factor of ~2.23 at the start of CH.