I built the WKNR 850 transmitter site in 1998-99, so I know quite a bit about it. In fact I am still the contract engineer there. WKNR feeds 52,500 watts into the daytime antenna common point, and 5,400 watts into the nighttime antenna common point. The day power is officially listed as 50kw days and 4.7kw nights on the FCC licenses. The reason for 4.7kw nights is due to the design of the antenna system and meeting certain criteria for the night pattern.
If you check Radio-Locator, you can see the approximate coverage and the way the pattern looks. You can see in much greater detail the shape of the patterns by logging on to the FCC.gov site and doing an AMquery to call up the licenses on file at the FCC.
WKNR uses a Harris DX50 for days and a DX10 for nights. 4 towers are used in the day pattern, and 4 used for the night pattern. The two most westerly towers are in common for both patterns.
The original nighttime 5kw pattern was designed in the mid 40's when WJW moved from Akron to Cleveland. A very deep "twin null" had to be designed to protect the 750 mile protected contour of KOA in Denver. If any more than 5kw had been proposed, at least 6 towers and possibly 9 towers would have been needed to contain the signal, and almost all of that power would have had to be sent north, so anything much over 5kw would have been a waste. Take a look at the 850 in Johnstown, PA as an example of needing 9 towers to contain 10kw at night.
The night pattern as it exists would not be possible to build as a new signal today due to changes in the AM rules over the years, and since the night signal is grandfathered, we could not have made any changes to the night signal when we rebuilt it in 1998-99 due to calculated overlap situations, and stay at 5kw.
On another note, the original power increase to 10kw days, done in the late 1950's, technically could have been taken to 50kw then. However the station was owned by George B. Storer, and he already owned WSPD in Toledo on 1370, and WJBK in Detroit on 1500. There would have been no signal overlap technically, but the old FCC duopoly rules in the 1950's prevented common ownership of any AM stations that had a 1 mv/m signal overlap. WSPD's 5kw non directional day signal could not overlap WJW's 10kw directional day signal, even though the frequencies were vastly different.
So, there for all of you is a bit of history about the 850AM signal in Cleveland.
Ted Alexander
If you check Radio-Locator, you can see the approximate coverage and the way the pattern looks. You can see in much greater detail the shape of the patterns by logging on to the FCC.gov site and doing an AMquery to call up the licenses on file at the FCC.
WKNR uses a Harris DX50 for days and a DX10 for nights. 4 towers are used in the day pattern, and 4 used for the night pattern. The two most westerly towers are in common for both patterns.
The original nighttime 5kw pattern was designed in the mid 40's when WJW moved from Akron to Cleveland. A very deep "twin null" had to be designed to protect the 750 mile protected contour of KOA in Denver. If any more than 5kw had been proposed, at least 6 towers and possibly 9 towers would have been needed to contain the signal, and almost all of that power would have had to be sent north, so anything much over 5kw would have been a waste. Take a look at the 850 in Johnstown, PA as an example of needing 9 towers to contain 10kw at night.
The night pattern as it exists would not be possible to build as a new signal today due to changes in the AM rules over the years, and since the night signal is grandfathered, we could not have made any changes to the night signal when we rebuilt it in 1998-99 due to calculated overlap situations, and stay at 5kw.
On another note, the original power increase to 10kw days, done in the late 1950's, technically could have been taken to 50kw then. However the station was owned by George B. Storer, and he already owned WSPD in Toledo on 1370, and WJBK in Detroit on 1500. There would have been no signal overlap technically, but the old FCC duopoly rules in the 1950's prevented common ownership of any AM stations that had a 1 mv/m signal overlap. WSPD's 5kw non directional day signal could not overlap WJW's 10kw directional day signal, even though the frequencies were vastly different.
So, there for all of you is a bit of history about the 850AM signal in Cleveland.
Ted Alexander
