Why Are LA and SF FM Stations Mostly Over-Powered?

[w9wi]

In regards to WOLX being just four miles south of the zone boundary, I've seen at least one source refer to it as a Class C1 station.

When I lived in the market, I assumed it was a class C -- before the Internet & GPS came along I would have had to go to the station to look at the license to know exactly where the tower was relative to 43-30-00

It is in fact a B in the CDBS database. Probably the largest consequence is that it's not protected from interference to the same extent it would be if it were four miles further north. (It's protected as if it was running 6.7kw; it is in fact running 37kw)

I'm pretty confident WOLX would have met Class C spacing requirements when the rules were established in the early 1960s. They've been around for a LONG time (late 1940s) & the area north & west of Baraboo was pretty devoid of FM signals in the 60s.

Of course, a LOT of new signals have been built since then. I'm sure it wouldn't meet C1 spacings today. 95.3 Beaver Dam comes to mind, and I'm sure they're not the only limitation.

In any case... The existing site is also approximately four miles south of the Wisconsin River. IOW, I think if it moved north into Zone II, the ridge which it currently occupies would probably at least partially block the signal into Madison. That, and the simple fact that the population densities are greater to the south of Baraboo than they are to the north would ensure any hypothetical Class C/C0/C1 WOLX would reach *fewer* listeners -- probably even if they were able to increase power.

I bet they wish they'd gone 100kw in the 1950s

 

[Schroedingers Cat]

I stayed in a hotel near LAX in Inglewood years ago to save time getting to the airport the next morning. The radio in the room would not pick up KOST 103.5 because there were two nearby Class A stations on 103.1 and 103.9. Seems like I could get it on the Sony SRF-A100, though the FM section of that is not that good, but the selectivity is pretty good.

 

[Schroedingers Cat]

I just discovered what I suspected-that WDET is still grandfathered at 48000 watts from 169 meters HAAT. It would be only allowed about 39 kW at that height for Class B equivalency. That would be about 61 kW from 150 meters. That placed the 60 dBu within the old 79 kW 1 mV/m contour from a new location nearby.

 

[radioman148]

In southern Wisconsin, consider WOLX 94.9 Baraboo/Madison; WERN 88.7 Madison; and WHAD 90.7 Delafield/Milwaukee. 54dBu on these stations is 83.36km, 76.56km, and 74.88km respectively. WOLX is an interesting case: the transmitter is only four miles south of the zone boundary -- if it were four miles further north, it would be in Zone II and would be an ungrandfathered Class C-something (C1, I suppose) station...

The result for WOLX is that they have a fairly competitive signal throughout most of the Madison metro instead of being just another rimshot.

WOLX has an excellent signal has I've listened to it going east past Milwaukee.

 

[Schroedingers Cat]

You must mean I-94 "East", unless you are on the other side of Lake Michigan, or on a boat. My Uncle from Park Ridge once gave me the following advice about walking in Chicago. "If you're going East and your hat starts to float, you've gone too far."

 

[radioman148]

You must mean I-94 "East", unless you are on the other side of Lake Michigan, or on a boat. My Uncle from Park Ridge once gave me the following advice about walking in Chicago. "If you're going East and your hat starts to float, you've gone too far."

That's what I meant. It was past midnight & my brain wasn't functioning well. ;D

 

[stormy01]

105.1 was once overpowered, 135kw IIRC. They aren't anymore.

WEAW was 180kW ERP from a 240' HAAT in Evanston. I know, I lived less than a mile away near Main St. and Dodge Ave. The only station that could bring the two bars on the "Green Eye" tuning meter on a Zenith Console Stereo together!
WFMT was operating at 135kW at something like 550' HAAT. How do I know for sure? I have quite a few copies of Vane Jones' North American Radio-TV Station Guides...

 

[Schroedingers Cat]

I just looked it up on David's site in the 1963 Broadcasting Yearbook. The WEAW-FM information is correct, 180 kW/240 ft. HAAT. WFMT was 135 kW from 540 feet. The address listed is 221 N. LaSalle St. Don't know what building this would be, or if just the studios or if the transmitter was at that location also.

 

[Schroedingers Cat]

I just looked up the address of WEAW in 1963. It was 1700 Central St. I almost ate at Mustard's Last Stand once. It was closed. Ended up at Sarkis' Café, up the stairs. Interesting place. It had pictures of all the famous people who had eaten there, on the wall. Jimmy Carter was there.

Looks like the towers are all gone. I'm sure the tower haters there couldn't wait to tear it down. Is it a park now?

 

[Schroedingers Cat]

Looks like the transmitter could have been there, it's the LaSalle Wacker Building, which is 41 Stories and has a tower on top. Perhaps some other TLs were there also? There's a cluster of HAAT's in this range in the 1963 Yearbook.

My first clue was that it was near City Hall. The words to "Jane (Beat The Machine Dame)" by John Landecker have historical value to non Chicagoans, "Down on LaSalle Street is where you feel the heat". I thought, Landecker, Lawyers, City Hall. I've been around there too but don't remember the building specifically.

 

[ftballfan]

In regards to WOLX being just four miles south of the zone boundary, I've seen at least one source refer to it as a Class C1 station.

When I lived in the market, I assumed it was a class C -- before the Internet & GPS came along I would have had to go to the station to look at the license to know exactly where the tower was relative to 43-30-00

It is in fact a B in the CDBS database. Probably the largest consequence is that it's not protected from interference to the same extent it would be if it were four miles further north. (It's protected as if it was running 6.7kw; it is in fact running 37kw)

I'm pretty confident WOLX would have met Class C spacing requirements when the rules were established in the early 1960s. They've been around for a LONG time (late 1940s) & the area north & west of Baraboo was pretty devoid of FM signals in the 60s.

Of course, a LOT of new signals have been built since then. I'm sure it wouldn't meet C1 spacings today. 95.3 Beaver Dam comes to mind, and I'm sure they're not the only limitation.

In any case... The existing site is also approximately four miles south of the Wisconsin River. IOW, I think if it moved north into Zone II, the ridge which it currently occupies would probably at least partially block the signal into Madison. That, and the simple fact that the population densities are greater to the south of Baraboo than they are to the north would ensure any hypothetical Class C/C0/C1 WOLX would reach *fewer* listeners -- probably even if they were able to increase power.

I bet they wish they'd gone 100kw in the 1950s

WOLX's tower is at one of the highest points of southern Wisconsin.

 

[radioman148]

In regards to WOLX being just four miles south of the zone boundary, I've seen at least one source refer to it as a Class C1 station.

When I lived in the market, I assumed it was a class C -- before the Internet & GPS came along I would have had to go to the station to look at the license to know exactly where the tower was relative to 43-30-00

It is in fact a B in the CDBS database. Probably the largest consequence is that it's not protected from interference to the same extent it would be if it were four miles further north. (It's protected as if it was running 6.7kw; it is in fact running 37kw)

I'm pretty confident WOLX would have met Class C spacing requirements when the rules were established in the early 1960s. They've been around for a LONG time (late 1940s) & the area north & west of Baraboo was pretty devoid of FM signals in the 60s.

Of course, a LOT of new signals have been built since then. I'm sure it wouldn't meet C1 spacings today. 95.3 Beaver Dam comes to mind, and I'm sure they're not the only limitation.

In any case... The existing site is also approximately four miles south of the Wisconsin River. IOW, I think if it moved north into Zone II, the ridge which it currently occupies would probably at least partially block the signal into Madison. That, and the simple fact that the population densities are greater to the south of Baraboo than they are to the north would ensure any hypothetical Class C/C0/C1 WOLX would reach *fewer* listeners -- probably even if they were able to increase power.

I bet they wish they'd gone 100kw in the 1950s

WOLX's tower is at one of the highest points of southern Wisconsin.

I remember reading that awhile back, which would explain why WOLX gets out so well.

 

[rfry]

RE: WFMT --

Looks like the transmitter could have been there, it's the LaSalle Wacker Building, which is 41 Stories and has a tower on top.

According to an email from the recently retired C.E. of WFMT, their studios and transmitter both were located at the LaSalle Wacker Building in 1963. The antenna was an RCA FM pylon on top of the building and it may still be there, per recent Google Earth pics. This was the era when WFMT began to be recognized for the excellent audio quality of their classical music format.

In 1969 when WFMT was owned by WGN, the transmit site moved to the Prudential Bldg, then the tallest in the Loop area, and shared building and mast space with WGN-TV, Channel 9. At that time they bought an RCA BTF-20E1. The studios were moved to 500 N. Michigan Avenue.

In the early '70s the WFMT transmit site moved to the Hancock Bldg into a space shared with another FM, and used the Alford master FM antenna/combiner system there.

In 1993 WFMT moved to Sears Tower and installed main/alternate Harris HT30CD 30 kW FM transmitters using digital generation of the FM waveform. They have their own Harris "CBR" antenna in the FM stack on top of the building. A bandpass filter in the tx room suppresses r-f intermods from the other stations there.

In 1970 WFMT was donated by WGN to WTTW (Channel 11), and in 1995 the studios of WFMT were moved to the WTTW studio building on Chicago's north side.

 

[Schroedingers Cat]

Wasn't WTTW on Marina City at one time, on the other tower from WLS-TV and the famous lighted Circle 7? Marina City is short as far as 60 story buildings go. They must have had another 300 feet of tower up there to get to the quoted HAAT, which was 893 feet as I recall. We had a really strong tropospheric reflection from there once, in early July in the early 1970s. WLS-TV and WTTW were extremely strong, because they were 316 kW. WGN was weaker, as they had already moved to Hancock at the time, and were 112 kW. WBBM-TV and WMAQ-TV were received, but not that clearly. I didn't have a TV with a UHF tuner at the time. I was only in the Marina City office building part once, and never was in the tower part. I stopped by and got a WCFL coverage map.

I've been looking at the website Emporis, which has a database of worldwide high rise buildings. They have an extensive database for most cities, even fairly small ones, like Traverse City (one hotel building, I didn't check Acme yet).

 

[rfry]

The second tower on Marina City was used by WFLD, Ch 32, who also had their first studios in the building.

The Marina City tower used by WLS-TV (Ch 7) was 285' long, and the RCA Traveling Wave antenna on top of it added about 140' to that.

As I remember those days, the WTTW transmit antenna was on a building at the NW corner of an intersection on N. Michigan Avenue. The building had a fairly narrow cross-section, and a kind of greenish, glazed look to it.

 

[davideduardo]

They have an extensive database for most cities, even fairly small ones, like Traverse City (one hotel building, I didn't check Acme yet).

Check Omena and Suttons Bay, too!

 

[Schroedingers Cat]

Here's the link to the 220 foot Grand Traverse Resort on Emporis. It has appeared in movies, but I suspect that they are mainly stock slides, not scenes shot for the movies. I don't know about high rises in Omena and Suttons Bay, but I'll check. I have some former classmates and a neighbor who recently built a house up near Nanagosa Trail.

http://www.emporis.com/building/grand-traverse-resort-hotel-acme-mi-usa

 

[Schroedingers Cat]

They show a 113 foot tower in Suttons Bay. That may be the Central Michigan University TV Translator tower for Northport. Towers are not all shown. The FCC database is much more accurate on these. If you are looking for sites, you may want to use Emporis in conjunction with the FCC website.

 

[stormy01]

As I remember those days, the WTTW transmit antenna was on a building at the NW corner of an intersection on N. Michigan Avenue. The building had a fairly narrow cross-section, and a kind of greenish, glazed look to it.

Wasn't WTTW at one time on the 1000 N. Lake Shore Dr. building? Or was that WXXW (then on channel 20)? Or were both channels 11 & 20 on "1000 LSD" [?] Channel 20, went dark in the mid-70's. The City Colleges of Chicago later acquired channel 20, and returned it to the air in the early 80's.

 

[rfry]

Wasn't WTTW at one time on the 1000 N. Lake Shore Dr. building? Or was that WXXW (then on channel 20)? Or were both channels 11 & 20 on "1000 LSD" [?] Channel 20, went dark in the mid-70's.

Yes, in the late 60s both WTTW and WXXW were on that building, which is located at the NW corner of Oak Street and Michigan Avenue, where inner N. Lakeshore Drive starts.