curious if anyone here thinks big signals are worth it?

[Schroedingers Cat]

I imagine that the Delco radio engineers (I actually met a couple of the retired ones, though they weren't still in Kokomo) spent time in Indianapolis testing particular problems like that.

The AFC tuned really wide on strong signals on our Magnavox Stereo Theater. Weak signals were fairly well separated, but you had to turn the volume up near the top to get a decent listening level. I could get signals 45-60 miles away on the folded dipole turnstile at 27 feet, WKNR-FM, WXYZ-FM, CKLW-FM from the old Riverside Drive TL, over the terrain ridge, but only with the volume cranked all the way up.

I could get both WJR-FM 96.3 and WBCM-FM 96.1, short spaced since the 1960s. They agreed (today the stations are both owned by Cumulus, and operate at maximum (WDVD 96.3) and close to maximum C0, but just a little over C1 height, for WHNN 96.1). IBOC on WDVD does limit WHNN's coverage though.

 

[davideduardo]

Here's the link to the GM Information Rack Service publication on eBay. The image of the page passing the 93.1 WIBC tower capturing 94.7 (not shown, but WFBM-FM/WFBQ, but in a different location far enough away for 93.1 to capture) is the fourth thumbnail image. Click on it and you can read it. Don't know if David has this publication on his site. I have one somewhere, but I don't know if I can find it.

https://www.worthpoint.com/worthopedia/vintage-general-motors-rack-pamphlet-1749405853

I don't have it but I found one on eBay and bought it.

 

[Schroedingers Cat]

I don't have it but I found one on eBay and bought it.

I read the pamphlet cover to cover scores of times when I was a kid. It also had a lot of information about the AM interference situation. There was a bar graph showing the number of stations on each frequency in circa 1941 and at the time of publication. Of course, frequencies like 700 and 1200 had just one, and the local channels had around 175 each as I recall. It also showed how as you went up the dial, the regional channels became increasingly packed due to the groundwave, though the 1250 to 1480 regionals were fairly even in number. Looking forward to seeing it again if I find it or on your site.

It always amazed me when I have brought this and a few other gems to a number of radio historians' attention.

I think I posted the link to the Chicago Tribune Larry Lujack interview from the late 1970s to some of you. It also talked a lot about the record rotation schedule. I also brought it to the attention of another radio archivist I have known since the 1970s, who grew up with John Landecker, and he sent the link to John. He was one of the last people Larry talked to before he died, and one of his few close friends, but neither he nor John had ever seen it before. Hope I can find a few other gems to share.

 

[charlestondxman]

I wonder if the low country and flat terrain has a lot to do with that. The few times I've been there, I remember things being pretty flat.

Yup. The flat terrain is everything with how those stations propagate. 100,000 watts carries in a huge way. WIWF has 99,000 because they aren’t grandfathered, off of a 1768’ TV tower. 89.3 uses 97,000 from a 1371’ tower. 95.1 is 100kw from a 1001’ tower.

Charleston’s TV channels moved to Awendaw (about 10-15 miles NE of town) back in the late 80s from much shorter towers closer to town.

Site of the week from last year: https://www.fybush.com/site-20191108/

 

[boombox4]

What do you mean by "if signals were weakened?" How would that happen?

Lower power levels?

 

[davideduardo]

Hope I can find a few other gems to share.

You reminded me of Santayana's "Those who cannot remember the past are condemned to repeat it."

(Often misquoted as "Those who do not learn from the past..." Same meaning, different words)

 

[Groove1670]

As with so many of these general questions, the answer is a hearty "it depends."

I am the chief engineer of a short-spaced, 3 kW-equivalent class A station that, once derated for height, puts out just 800 watts ERP - and we're routinely in the top 3 stations in our market.

It works for us because we're perfectly centrally located, atop the tallest building downtown (our top antenna bay is the highest point above sea level in the entire county), and because with a hip-hop/R&B format, our core audience is mostly close to the center of the market. But we're also a geographically compact market in general, with probably 70-75% of the pop count inside our 70 dBu contour.

Most formats in most markets wouldn't do as well as we do with our signal. We even have some areas where we'd like to be heard better - there's a tower farm a few miles outside downtown that has three Bs, a B1 and two As that create an intermod/overload mess that wipes everything else, including us, for a mile or two, and it would be nice to have more power to overcome that noise.

There are so many factors. We are carried on a 10 watt translator, and the signal is good. We are 869 FT AHSL and look down on the city. In fact the there are a few translators with ERP of 75 watts or less with a good signal in the makrket. In our case there is no hi power channel on the frequency. There are several 250w translators that get chewed up because of C or C1 at 1500+ feet on the frequency (tropo). On severe ducting days the 10W signal has better coverage than the 250W signals.

The coverage map always doesn't always tell the story. I'll always tell applicants to listen to a channel before filing a application, don't rely on the study or report.

 

[Schroedingers Cat]

As I have read and been told over the years, the FCC F(50,50) and F(50,10) curves were based on a truncated Longley Rice type model with several other factors eliminated. It worked in terrain that was quite flat, with no significant terrain holes. That was true in coastal areas near bodies of water and slight upward grade from the "coast" of the body of water. In places like New York City and Chicago, that is a reasonable model. This was later supplemented with the "Terrain Roughness Factor", which was from another propagation model using more terrain factors, called Bullington. Really, as a minimum, you need to consider a Longley Rice type model, and that has sometimes needed to be enhanced with buildings and trees in databases. But you are right, the only way to accurately measure a signal is with a field strength meter.

 

[fordranger797]

One major positive to the Portland radio market is that the terrain is much more forgiving to terrestrial FM broadcasting. A translator that might be entirely useless in Seattle actually will provide fairly good coverage in the Portland Metropolitan area (as you have already pointed out). The centrally located mountains in Portland provide the ideal location for broadcasting to both the east and west side of the market. Looking at some of the Radio Locator coverage maps, I think it is pretty clear that the far reaches of the metropolitan area are largely out of range, but you won't be doing too badly if you're listening closer to the city. 99 watts at around 1,700 feet looks pretty good.
https://radio-locator.com/cgi-bin/pat?call=K275CH&service=FX

Not to mention, it's interesting to see some of these translators providing some more variety to the band.

 

[bobdavcav]

Quite true. I think 102.9 has one of better translator signals, which I'm surprised at given Centralia was audible before that translator moved from 102.7. The other good one is 92.7, though for some reason the kitchen radio doesn't get that one as well. Both frequencies have stations in the gorge, but it's not quite as bad as 102.3, which has to contend with signals to the south, east, and northwest. That makes for a pretty bad signal even close in.

 

[fordranger797]

Quite true. I think 102.9 has one of better translator signals, which I'm surprised at given Centralia was audible before that translator moved from 102.7. The other good one is 92.7, though for some reason the kitchen radio doesn't get that one as well. Both frequencies have stations in the gorge, but it's not quite as bad as 102.3, which has to contend with signals to the south, east, and northwest. That makes for a pretty bad signal even close in.

With how close together many coverage maps have become, it isn't too surprising that 102.9 exists in Portland, but it seems (to me at least) that 102.7 would be the better frequency for that translator to avoid KZTM. Are you also able to receive KXXO down at your new house? I would imagine that they are audible, but weak with a 96.3 signal in Portland now.

 

[Schroedingers Cat]

And yet the FCC and industry will not even grant a few MHz of TV spectrum as an expanded band. There are plans that demonstrate that just 2 MHz could take the place of 1000-2000 1000 watt stations to replace translators. Of course, there is the argument that you would need a new receiver or converter, and the argument that radio is dead, and that people don't even have radios any more, and not just the whippersnappers with all the latest audio delivery technology, and that nobody would buy new radios or converters. FM is rapidly becoming a "vast wasteland" of limited range signals, now interfered with even from noise from newer electronic devices. The same arguments were being made from at least 1960 on about AM. The NAB and some station groups filed petition comments that stated that even the reasonable Section 73.215 would result in "AMization" of the FM Band. I wonder how many stations would continue with IBOC, with all it's problems and questionable audio benefits, and even detriments to the analog signal, if the FCC didn't require HD-2 delivery of audio to many of those translators.

 

[bobdavcav]

With how close together many coverage maps have become, it isn't too surprising that 102.9 exists in Portland, but it seems (to me at least) that 102.7 would be the better frequency for that translator to avoid KZTM. Are you also able to receive KXXO down at your new house? I would imagine that they are audible, but weak with a 96.3 signal in Portland now.

Yes, I can get KXXO, though I missed them completely on my first scan of the dial.

 

[bobdavcav]

And yet the FCC and industry will not even grant a few MHz of TV spectrum as an expanded band. There are plans that demonstrate that just 2 MHz could take the place of 1000-2000 1000 watt stations to replace translators. Of course, there is the argument that you would need a new receiver or converter, and the argument that radio is dead, and that people don't even have radios any more, and not just the whippersnappers with all the latest audio delivery technology, and that nobody would buy new radios or converters. FM is rapidly becoming a "vast wasteland" of limited range signals, now interfered with even from noise from newer electronic devices. The same arguments were being made from at least 1960 on about AM. The NAB and some station groups filed petition comments that stated that even the reasonable Section 73.215 would result in "AMization" of the FM Band. I wonder how many stations would continue with IBOC, with all it's problems and questionable audio benefits, and even detriments to the analog signal, if the FCC didn't require HD-2 delivery of audio to many of those translators.

I would suspect that several stations would shut down HD, but there is also a significant percentage of stations that do run separate programming on subchannels without translators. I'm honestly not sure if KKRZ would shut down HD or if their HD2 would just become the next online iHeart format. Until internet streaming rates are equal to that of terrestrial stations, you're not going to see many iHeart stations shut down their HD.

 

[bobdavcav]

I've been thinking about this thread a bit more, and one market that I don't understand why it has so many class C signals is Honolulu. Sure, there's nothing around it to get in the way, but there's also not enough land to justify that big of a signal. I saw on the Hawaii board that a C1 could put a 70 DBU over the entire island, but lots of stations are full Cs there. I'm not sure if the C1s that are there would cover the entire island, but that's because of where they are located.

 

[davideduardo]

I've been thinking about this thread a bit more, and one market that I don't understand why it has so many class C signals is Honolulu. Sure, there's nothing around it to get in the way, but there's also not enough land to justify that big of a signal. I saw on the Hawaii board that a C1 could put a 70 DBU over the entire island, but lots of stations are full Cs there. I'm not sure if the C1s that are there would cover the entire island, but that's because of where they are located.

A station wants the "biggest" signal possible to penetrate buildings in the area they serve. It's not just about extending coverage; it is about being listenable on every radio in the market.

 

[Schroedingers Cat]

A station wants the "biggest" signal possible to penetrate buildings in the area they serve. It's not just about extending coverage; it is about being listenable on every radio in the market.

Location Location Location often has as big an impact as ERP. I've seen spectrum scans done in Grand Rapids, and the Class A stations, WFGR and WTRV, are stronger in many areas in the center of population than 320 kW WBCT and 265 kW WSRW, which are close to 30 miles away on TV TL towers that were put out there to serve Kalamazoo and Battle Creek. I often wonder whether they would be better off if they could split into 3 Class As or Class B1s. They could save some power bills for sure.

 

[PTBoardOp94]

I've been thinking about this thread a bit more, and one market that I don't understand why it has so many class C signals is Honolulu. Sure, there's nothing around it to get in the way, but there's also not enough land to justify that big of a signal. I saw on the Hawaii board that a C1 could put a 70 DBU over the entire island, but lots of stations are full Cs there. I'm not sure if the C1s that are there would cover the entire island, but that's because of where they are located.

Several of these full C, C0 and C1 stations operate translators or on-channel boosters on the island, such as KRTR, KLUU, and KIPO. I've never traveled to Hawaii, but I'm guessing they build those translators on account of the coverage from their primary signal being awesome all over the island.

 

[bobdavcav]

KRTR is a weird situation, being as there are two places in Hawaii with the name Kailua, not sure if I spelled that right. There's one near Honolulu where the main 96.3 is located, but then there's another place on the big island with the same name served by a 105.7 translator. I'm guessing that's the reason for that translator, but I don't know what the FCC's policy on this is. Perhaps David could answer that. I've been to Honolulu, but didn't have a radio of my own and so didn't get to DX. Even so, I'm not sure what I'd get from the big island, or really any of the other islands. I would imagine that the big island in particular would be difficult, since it's over 100 miles away, but then again most of that path is water.