680 Signal

I asked this a couple of years ago, and it was answered. But I was in Memphis over the weekend and drove to the 680 transmitter site so I'm thinking about it again.

What was the reason 680's daytime power was decreased to 8,000 watts? I think it had something to do with a bad main tower forcing relocation to another one of the towers for daytime. I seem to recall that 8,000 watts at the "new" tower were equivalent to 10,000 at the former main tower.

Is there anyone who could remind me of this?

Thanks so much.

It has been many years since I worked on that array, but I suspect it is simply a paper change. The "real" power of a station is computed as signal strength at one kilometer to take into account antenna efficiency and such. I think the antenna input power has always been 8 KW.

radiosaur said:

It has been many years since I worked on that array, but I suspect it is simply a paper change. The "real" power of a station is computed as signal strength at one kilometer to take into account antenna efficiency and such. I think the antenna input power has always been 8 KW.

Click to expand...

Thanks, radiosaur.

There are also two 100kw'ers using one tower with many many bays....

I counted 12 bays on that tower when I was there. But another one of the towers has 3 or 4 FM bays. Are you sure both stations are on the tower with the 12 bays?

Yes from what I was told when I was at the facility both kjms and whrk use the 12 bay set up with 100kw, if you count the bays in the photo I posted you will see there are indeed 12 bays.

From long ago memory, the three bay FM antenna on the NE tower in the array was the back-up antenna for WHRK. Years ago, it may well have been the actual WMPS-FM antenna.

After the main tower collapse (circa 1978-79), this back up FM antenna was used for K-97 while the tower was replaced. Both AM 680 and K-97 operated under FCC special authorization at low power during replacement. The coverage patterns of both stations were very ugly for a short time......

It doesn't seem like there are many FMs that use more than 10 bays today.

Back as a cub announcer in 1986 at KRXL 94.5 Kirksville MO, the 400 foot tower behind the station used 12 bays to make 100 kW. Transmitter loafed along at 16 to 17 kW output power. The bays are long gone today, replaced by a 1000 ft facility, and the tower out back now only contributes to the chorus of "aahs" nightly on 1450.

joebtsflk1 said:

It doesn't seem like there are many FMs that use more than 10 bays today.

Back as a cub announcer in 1986 at KRXL 94.5 Kirksville MO, the 400 foot tower behind the station used 12 bays to make 100 kW. Transmitter loafed along at 16 to 17 kW output power. The bays are long gone today, replaced by a 1000 ft facility, and the tower out back now only contributes to the chorus of "aahs" nightly on 1450.

Click to expand...

When I passed by the facility about 3 years ago the bays were still up, and the set up looked so strange I had to snap a shot..