WBBM 780 to move transmitter again

[CADXER]

... and take WSCR 670 with them.

As reported elsewhere, Audacy has applied with FCC to move WBBM 780 and WSCR 670 from the Bloomingdale, IL site to the WYLL daytime site in Des Plaines, IL, where they will use the two unused towers. If approved by FCC WBBM gets to slightly increase their powers to 45 kW daytime, 43 kW nighttime.

 

[boiseengineer]

Higher power because the tower is way WAY shorter and less efficient. Less groundwave more skywave.
Now on a 740 foot tower. Proposed is 225 feet tall.

 

[icybluelake]

Higher power because the tower is way WAY shorter and less efficient. Less groundwave more skywave.
Now on a 740 foot tower. Proposed is 225 feet tall.

What is that likely to do to people in the hinterlands who want to listen to WBBM or WSCR during the daytime? Will it be as bad as I think? What I think is that it will limit each signal to maybe 200-225 miles or so.

 

[JJSPC]

What is that likely to do to people in the hinterlands who want to listen to WBBM or WSCR during the daytime? Will it be as bad as I think? What I think is that it will limit each signal to maybe 200-225 miles or so.

So stream them?

 

[davideduardo]

What is that likely to do to people in the hinterlands who want to listen to WBBM or WSCR during the daytime? Will it be as bad as I think? What I think is that it will limit each signal to maybe 200-225 miles or so.

Outside of the Metro Survey Area, stations don't care about those listeners at all. There is no revenue to be had, and so they are ignored.

 

[boiseengineer]

With that short of a tower you'll have destructive selective fading 40~100 + miles out so nobody will be able to listen at night outside the metro.

 

[icybluelake]

Outside of the Metro Survey Area, stations don't care about those listeners at all. There is no revenue to be had, and so they are ignored.

I already understand that perfectly, David. My question, however irrelevant you may deem it, does not relate to revenue. Many or all of us here are DXers and daytime reception is also a matter of curiosity for some of us.

And yes, I know how to stream, but my car doesn't.

 

[Ke4kls]

With that short of a tower you'll have destructive selective fading 40~100 + miles out so nobody will be able to listen at night outside the metro.

Would adding a capacitance hat on the towers for these stations (on 670 and 780) like what was done on KFI improve the signal considering the compromise of shorter towers?

 

[Kelly A]

I already understand that perfectly, David. My question, however irrelevant you may deem it, does not relate to revenue. Many or all of us here are DXers and daytime reception is also a matter of curiosity for some of us.

But the reality is, broadcasters don't benefit in any way from DX'ers.

And yes, I know how to stream, but my car doesn't.

Do you have a smartphone? What about a Bluetooth or USB interface?

 

[davideduardo]

Would adding a capacitance hat on the towers for these stations (on 670 and 780) like what was done on KFI improve the signal considering the compromise of shorter towers?

That, or even better, use the top guy wires as a top-loading system. I had a short tower for my 570 AM in Ecuador, and we had 6 "guy" wires off the top section. They added nearly 100 feet of Phillystran (copper on the outside, steel threading inside) every 60° around the tower and considerably increased the base impedance.

 

[boiseengineer]

Would adding a capacitance hat on the towers for these stations (on 670 and 780) like what was done on KFI improve the signal considering the compromise of shorter towers?

Doesn't actually change the radiation of the antenna much, mostly changes the base impedance to something that is easier to match the antenna tuning unit to like DavidEdwardo mentioned. Station in Boise ended up with 6 ohms at a shared site. They lost nearly 20% of their power in heat making the match.

 

[davideduardo]

Doesn't actually change the radiation of the antenna much, mostly changes the base impedance to something that is easier to match the antenna tuning unit to like DavidEdwardo mentioned. Station in Boise ended up with 6 ohms at a shared site. They lost nearly 20% of their power in heat making the match.

And I thought my 18 ῼ was dreadful. But at least the coils and caps in the doghouse did not heat up... at 10,500 feet AMSL.

The bigger advantage was that the increased impedance flattened a bit the reactance on either side of the carrier, improving the bandwidth a bit.

 

[boiseengineer]

And I thought my 18 ῼ was dreadful. But at least the coils and caps in the doghouse did not heat up... at 10,500 feet AMSL.

The bigger advantage was that the increased impedance flattened a bit the reactance on either side of the carrier, improving the bandwidth a bit.

Tower is skirted operating at 1350 with a impedance of 150 ohms. At 890 it was 6 ohms. 2-tower DA for 890. CP was for 250 watts. They got something like 360 watts TPO from the FCC for total losses also due to the other tower being really short.
That was the 890 night site. When it would first come on the BE 500 would VSWR down until things warmed up.
It's gone now.