When Did Local AM's Quit Lowering Their Night Power to 250 watts?

[doug41160]

When did local AM stations quit lowering their power to 250 watts at sunset? Why did the FCC start allowing AM locals to continue operate at 1000 watts at night? It sure hasn't help their night signals here where i live because i still cannot pull in WMRN-AM, Marion, or WCWA-AM, Toledo, at night! I was told by a former WMRN employee that even at night, they still had a 20 mile signal range at night with 250 watts. I tested WMRN's night signal a few years ago and found that their night signal could still reach old state route 30 north of the village of Nevada in Wyandot County which pretty much compares to being similar to their former 250 watt night time signal strength. With that being pointed out, they may have well just kept reducing the local's signals to 250 watts or at least raising their night signal strength to maybe 300, 350, or 400 watts to help them reach out a few more miles.

 

[davideduardo]

When did local AM stations quit lowering their power to 250 watts at sunset? Why did the FCC start allowing AM locals to continue operate at 1000 watts at night? .

The change in night power for what was called Class IV back then occurred in the 1985-1986 period. Since stations already had 1 kw daytime, going to 1 kw fulltime did not require any investment.

Class IV's originally had 250 watts fulltime (a few were just 100 watts). The raise in daytime power was intended to improve coverage a bit but mostly it let stations overcome increasing man-made noise. The move to night power helped in the local coverage area, but increased interference in the fringe areas.

 

[vchimpanzee]

I know this much. Charlotte has annexed the college I graduated from and I was there when WIST, Charlotte's first Top 40 station, went off the air. It had a better frequency in its early days and 61 Big WAYS took over the role as the leader with Top 40 listeners, but it was still a sad day when the station went off the air, and I knew when the final moment would happen. With 250 watts, I could hardly hear anything. I wasn't in Charlotte at the time but where I was is now. Two 1000-watt stations, which had to lower their power from 5000 watts, sounded good.

 

[semoochie]

The change in night power for what was called Class IV back then occurred in the 1985-1986 period. Since stations already had 1 kw daytime, going to 1 kw fulltime did not require any investment.

Class IV's originally had 250 watts fulltime (a few were just 100 watts). The raise in daytime power was intended to improve coverage a bit but mostly it let stations overcome increasing man-made noise. The move to night power helped in the local coverage area, but increased interference in the fringe areas.

I was in the process of posting this earlier, when a Firefox update knocked me right off of the page! I'll try again: KBCH Lincoln City OR was one such station, 250 watts on 1400. They deemed it preferable to become a 1KW daytimer on 1380, so that's just what they did. Decades later, they moved back to 1400 and added night power of 1KW.

 

[Larry the radio guy]

When the five local channels, 1230,1240,1340,1400,1450 and 1490 were granted night time power equal to daytime power ( not all got the increase to 1,000 watts but most did ) the night coverage remained the same because the interference level ratio remained the same as the ratio between station's powers remained the same. The power increase was to make the local ground wave signal strong at night near the station. This ground wave signal had become degraded because of interference within the daytime coverage area and to cut to 250 at night let the interference cause more trouble to reception close to the stations. Night coverage in general I have found remains about 5 miles radius. Beyond that its pot luck.