WKNY 1490 Kingston Signal Question

[MHVRadiofan]

This is a question for those with some technical knowledge .First I must emphasize that this has nothing whatsoever to do with sunrise or sunset times . This occurs even if sunrise is at 5:00AM and sunset at 8:30 PM or is getting shorter like now .WKNY , 1490 Kingston has an unlimited 1KW non- directional signal , with the same constants day and night . They put a decent signal but a bit weak into Poughkeepsie during the day but early in the morning say 7:00 AM I can’t receive them at all. There is just weak background chatter . The same goes for the evening . Again sunrise/set times have nothing to do with it . What could cause this ?

 

[BobOnTheJob]

This is the curse of night time AM radio...but it's worse on "graveyard' channels...with 1490 being one of them. There are hundreds of stations on that frequency, virtually all running 1KW at night and the result is a sea of interference that you need a quite robust signal to over-ride. As you indicated, your signal in the city in question "a bit weak". The nightime signals from the many other 1490's are "a bit strong". End result, you drown in the clutter until shortly after sunrise. From my experience, at least in the Ohio Valley, stations on graveyard channels that may go 35 miles during the day are limited to perhaps 7-9 miles at night. It's a sad fact of life, but we've lived with it for decades & I don't look for it to improve unless most of the stations on 1490 (and other graveyards such as 1230, 1240 & 1400) leave the air.

 

[amfmsw]

And don't forget the nice and quiet 1450Kc.

Bob, do you think these stations served better when we pulled in the reigns at night to 250watts?

 

[BobOnTheJob]

And don't forget the nice and quiet 1450Kc.

Bob, do you think these stations served better when we pulled in the reigns at night to 250watts?

Actually, I don't. I've seen it argued both ways, but I come down on the side that the interference levels are equal as long as everyone is running the same power, be it 250 watts or 10 kilowatts. But the increased signal level from 1 kilowatt over-rides the electrical interference that the AM band is infested with in many receiver locations. Actually, there is another advantage to everyone staying at the same power 24/7...around sunrise & sunset, the stations that changed to 250 watts were competing with stations still at 1 kilowatt where the sun was still up. At least on paper, that made the times around sunrise & sunset a little more interference prone. Plus, not having to switch power 730 times a year makes station operation simpler. All in all, I was glad to see the change in rules that allowed this. What I'd really like to see is a program that would give AM stations an FM translator that was "etched in stone" in exchange for shutting off the AM signal. That would do more to clean up the AM band for those who wish to remain there than just about anything else I can imagine...and I bet there would be many takers.

 

[maineengineer]

The original post got my attention, with its subject line, as my first fulltime job in radio was at WKNY in the mid 60's (the year, not my age). Since the poster asked what "could" cause the described phenomenon, I'd theorize that close-in cancellation of groundwave by skywave is occuring, even though Kingston and Poughkeepsie are only about 15 air miles apart. Further, even though the effect was described as apparently not sunrise or sunset related, the pattern is close enough to be generally characterized as daytime-nighttime occurences. The raising and lowering of the reflective layers of the upper atmosphere are not typically in strict synchronization with the local sun times which are more closely related to the seasonal tilt of the earth on its axis. The medium wave AM broadcast band is particularly subject to this effect, and there doesn't have to be a whole lot of power involved to experience the phenomenon.

With regard to the side-thoughts of this thread, about the efficacy of the fulltime Class IV regionals, most (if not all) found that the "in-town" coverage at night was considerably improved at 1 kW, with its greater ability to overcome the electrical, man-made noise, etc., but that the "fringe" coverage at night was very much less than it was even at 250 Watts, by virtue of the increased interference levels encountered. The NAB got what wanted but it very much wasn't the relief the owners anticipated, especially vis-a-vis the new electric bill.