• Get involved.
    We want your input!
    Apply for Membership and join the conversations about everything related to broadcasting.

    After we receive your registration, a moderator will review it. After your registration is approved, you will be permitted to post.
    If you use a disposable or false email address, your registration will be rejected.

    After your membership is approved, please take a minute to tell us a little bit about yourself.
    https://www.radiodiscussions.com/forums/introduce-yourself.1088/

    Thanks in advance and have fun!
    RadioDiscussions Administrators

U.S. AM Radio Station Heard Coast To Coast

Cincinnati Kid said:
Despite all of the research that I did for that thesis and in the studies I did both before and afterward, it has never been clear to me just how far WLW was heard on a regular basis when they were 500,000 watts. I've heard that the daytime signal was so great that the station could be clearly received many hundreds of miles away. I've even heard that it could also be received in downtown Los Angeles. I do recall being told that even if a radio station increases its power ten times over what it was (50,000 watts to 500,000 watts) doesn't mean it can be heard ten times farther. Of course, suffice to say during that 1934-1939 period, WLW covered quite a few miles. It might be noted that even after the power was restored to 50,000 watts, WLW's 700 k.c. frequency was on a clear channel.
Click to expand...

To double the coverage, a four time increase in power is needed. So WLW's 50 kw coverage would be doubled with 200 kw, and then increased by another roughly 50% by going to 500 kw.

But there are other factors.

Back in the 30's there was far less man-made noise. And those old tube radios were actually very good. So a much weaker signal could be heard farther away than in the more recent years. That goes for both day and night reception.

The AM band was not very crowded... about a fifth of the number of stations there are today. So there was far less local interference from other stations. At night, stations like WSM with "just" 50 kw got mail from all of the 48 states... just not as much from Washington as from Georgia, but mail came from all over the nation.

And, whether today or back then, wide coverage stations really don't have "perfect circle" coverage. Difference in ground conductivity favored certain directions, and cut into the signal in others. WLW apparently did very well in Indiana and Illinois, but the lower conductivity of Kentucky and West Virgina and western PA reduced the effective distances to the east and south.

At night, conductivity is not the relevant factor for skywave. On a clear frequency, with no interference on 690 or 710, the signal was viable for great distance. But around Toronto, New York, Seattle and Los Angeles, those adjacent channels likely made reception difficult.

WLWs own daytime coverage map showed a "good signal" up into southern Michigan, down to the TN border and comparable distance to the west and east.

Important to remember is that in the Golden Age of radio, nights were prime time... unlike today when many stations automate nights and can't sell much advertising there. That is when the big network shows were on and where the money was made. And at night, WLW was truly "the nation's station".

For those unfamiliar, here is a booklet about the station and its 500,000 watt transmitter:

https://www.americanradiohistory.com/Archive-Station-Albums/WLW_Brochure-1935-LR.pdf
 
Last edited:
DavidEduardo said:
Important to remember is that in the Golden Age of radio, nights were prime time... unlike today when many stations automate nights and can't sell much advertising there. That is when the big network shows were on and where the money was made. And at night, WLW was truly "the nation's station".
Click to expand...

Of course there's not much difference between automating at night and running network programming from NYC. Stations were perfectly willing to give up their highest rated daypart for national programming, for the chance to make money on the audience the shows attracted. This was before TV stole away night time viewers. But local TV stations operate pretty much the same way today. But contrary to the mythology, radio has never been completely live & local. Even on stations as powerful as WLW.
 
TheBigA said:
Of course there's not much difference between automating at night and running network programming from NYC. Stations were perfectly willing to give up their highest rated daypart for national programming, for the chance to make money on the audience the shows attracted. This was before TV stole away night time viewers. But local TV stations operate pretty much the same way today. But contrary to the mythology, radio has never been completely live & local. Even on stations as powerful as WLW.
Click to expand...

That's a great point.

Local shows were often "fill" between the network shows. They were not expected to make as much money, and often they were logged as "sustaining" which was a long-unused term for "we can't sell any ads there but we have to run something."
 
Cincinnati Kid said:
There are many stories such as these. Regarding the light continuing to burn at a local hotel (I heard it was a motel), I heard the owner of the facility actually put up a sign advising of what was causing it to stay on and got some publicity for his business that way.
Click to expand...

Perhaps we could call it a motor hotel. Did WLW cause the "NO" part of the "NO VACANCY" sign to stay lighted?
 
DavidEduardo said:


To double the coverage, a four time increase in power is needed. So WLW's 50 kw coverage would be doubled with 200 kw, and then increased by another roughly 50% by going to 500 kw.

But there are other factors.

Back in the 30's there was far less man-made noise. And those old tube radios were actually very good. So a much weaker signal could be heard farther away than in the more recent years. That goes for both day and night reception.

The AM band was not very crowded... about a fifth of the number of stations there are today. So there was far less local interference from other stations. At night, stations like WSM with "just" 50 kw got mail from all of the 48 states... just not as much from Washington as from Georgia, but mail came from all over the nation.

And, whether today or back then, wide coverage stations really don't have "perfect circle" coverage. Difference in ground conductivity favored certain directions, and cut into the signal in others. WLW apparently did very well in Indiana and Illinois, but the lower conductivity of Kentucky and West Virgina and western PA reduced the effective distances to the east and south.

At night, conductivity is not the relevant factor for skywave. On a clear frequency, with no interference on 690 or 710, the signal was viable for great distance. But around Toronto, New York, Seattle and Los Angeles, those adjacent channels likely made reception difficult.

WLWs own daytime coverage map showed a "good signal" up into southern Michigan, down to the TN border and comparable distance to the west and east.

Important to remember is that in the Golden Age of radio, nights were prime time... unlike today when many stations automate nights and can't sell much advertising there. That is when the big network shows were on and where the money was made. And at night, WLW was truly "the nation's station".

For those unfamiliar, here is a booklet about the station and its 500,000 watt transmitter:

https://www.americanradiohistory.com/Archive-Station-Albums/WLW_Brochure-1935-LR.pdf
Click to expand...

I have heard this point before about AM stations in the 20s and 30s traveling great distances in the daytime, sometimes with very little power. I once heard that they wanted to test to see if KGW Portland could be heard inside the Oregon Caves, about 250 miles away in the Coast Range. The experiment was unsuccessful but only because it didn't make it INSIDE the caves!
 
semoochie said:
I have heard this point before about AM stations in the 20s and 30s traveling great distances in the daytime, sometimes with very little power. I once heard that they wanted to test to see if KGW Portland could be heard inside the Oregon Caves, about 250 miles away in the Coast Range. The experiment was unsuccessful but only because it didn't make it INSIDE the caves!
Click to expand...

The difference in "those days" was the lack of man made noise. In most case the 0.5 mV/m signal was quite usable, and way down to the 0.1 was often listenable. Today, the ITU says that in cities, 15 mV/m is the needed signal to overcome noise.

As an example, KFI in the "Golden Age" was its network's station for Palm Springs, which is inside, barely, the 1 mV/m coverage area of the station. But the signal was most usable. Today, the signal is noisy in the daytime anywhere that there are buildings and houses and power lines.

Another example is my own experience with my 5 kw AM in Quito, Ecuador on 660 around 1970. When I was at my station in Cuenca, a good 190 miles away, I could easily listen to the station in the daytime with a weak, but clear signal. Today, that power at a comparable frequency would not be usable for more than about 50 miles in any direction.
 
WLW was not alone in its high-powered aspirations. In the 1930s, KNX, WJZ, WHAS, WJR, KDKA, KFI, WSM, WOAI, WOR, WGY, KSL, WBZ, and WHO sought increases to 500 kW. In 1962, WLW, WJR, WSM, WGN, and WHO applied for boosts to 750 kW. Two years later, in its battle with WNYC, WCCO filed for the same upgrade.
 
DavidEduardo said:


The difference in "those days" was the lack of man made noise. In most case the 0.5 mV/m signal was quite usable, and way down to the 0.1 was often listenable. Today, the ITU says that in cities, 15 mV/m is the needed signal to overcome noise.

As an example, KFI in the "Golden Age" was its network's station for Palm Springs, which is inside, barely, the 1 mV/m coverage area of the station. But the signal was most usable. Today, the signal is noisy in the daytime anywhere that there are buildings and houses and power lines.

Another example is my own experience with my 5 kw AM in Quito, Ecuador on 660 around 1970. When I was at my station in Cuenca, a good 190 miles away, I could easily listen to the station in the daytime with a weak, but clear signal. Today, that power at a comparable frequency would not be usable for more than about 50 miles in any direction.
Click to expand...

In case this is still not clear, we're talking about the interference level of 80-90 years ago. When I heard about this 50 years ago, it was already nothing like that and I found it hard to believe!
 
Kemosabe said:
WLW was not alone in its high-powered aspirations. In the 1930s, KNX, WJZ, WHAS, WJR, KDKA, KFI, WSM, WOAI, WOR, WGY, KSL, WBZ, and WHO sought increases to 500 kW. In 1962, WLW, WJR, WSM, WGN, and WHO applied for boosts to 750 kW. Two years later, in its battle with WNYC, WCCO filed for the same upgrade.
Click to expand...

There are a couple of hundred pages of correspondence and reports about the Clear Channel Broadcasting Service at https://www.americanradiohistory.com/WSM_Clear_Channels.htm

That was the association of stations that wanted greater power on the 1-A clear channels. They did not give up until the FCC finally said "no" and began proceedings to license additional stations on those national clear channels with the objective of serving areas with poor radio service. Stations were granted on many of those channels in places like Guymon, Casper, Kalispell, St. Georges, Four Corners, Roswell, Eugene, Boise, Reno, Las Vegas, Grand Junction, and Lexington.
 
Last edited:
spiritof67 said:
David, I have to wonder if you still have any of those tapes from HJED you recorded years ago.
Click to expand...

I wish! They stayed in Cleveland and were thrown out when I moved to Ecuador a couple of years later.
 
What would be the "health risks" today if a station was allowed to broadcast at 500,000 watts. People complain now about cell towers giving off radiation, I can only imagine what they would be saying about a super station at 500,000.
 
Don CT said:
What would be the "health risks" today if a station was allowed to broadcast at 500,000 watts. People complain now about cell towers giving off radiation, I can only imagine what they would be saying about a super station at 500,000.
Click to expand...

There seems to be no health issue regarding medium wave signals. While NIMBY groups bring it up regularly when some station tries to relocate near them, the health concern is rapidly dismissed due to lack of evidence.

But yes, you are right, uninformed or ignorant people will object without ever looking for the facts, first.

There are / were many, many 500,000 to 2 million watt stations all over Europe, the Middle East and Asia and none has been reported to have been the cause of health issues.

500 kw TWR in Bonaire (now 440 kw) has run from the 60's and there is no health issue reported there. Same with 250 kw XEW in Mexico City...

It is infinitely more dangerous to live near a freeway or main highway than next to a powerful radio station.
 
For many years, in addition to the WLW transmitter and tower in Mason, the area was also the site of a Voice of America installation with its multiple towers. Quite a bit of radio power going on there at that time.
 
As Cincinnati folks know, the former Voice of America transmitter site is still there as a museum and meeting facility. The land the towers sat on has been turned into Voice of America Park.
 
There is a tiny minority of people out there who claim to suffer adverse affects from exposure to RF, although it is hard to quantify exactly what types and amounts of RF are "affecting" them. Many of them blame cell phone towers for their afflictions. Some claim to be affected by the presence of Wi-Fi signals.

These people may be genuinely experiencing symptoms of some kind. Whether it has anything to do with RF is doubtful. There is apparently a community of such people living near Green Bank, WV, which is a "radio quiet zone" because of the radio astronomy that takes place there. No cell phones allowed.

I was contacted once by an individual who claimed to be suffering ill effects from a radio tower we built near his home for a class-A FM station. He identified it as a "cell tower", although at the time there was no cell site there. I ran some numbers and determined that the worst-case RF level from our station, at his house, was probably less than what is allowed to leak from the average microwave oven.

If you watch "Better Call Saul" on AMC, you will recall one of the major characters suffered from a similar problem, to the extent that he shut off the power in his house and used camping lanterns for light...although it was later revealed that his problem was entirely psychological.
 
Wimmmex said:
I think when Herb Jepco did his overnight show...he was originally on KSL Salt Lake....and WHAS Louisville. Ity coverred a good deal of the continent.

KSL = http://www.nf8m.com/pattern_maps/US-CA_nighttime/N-map_1160KHz.html

WHAS = http://www.nf8m.com/pattern_maps/US-CA_nighttime/N-map_840KHz.html

Add WBZ to that plan, and it would cover almost the whole US, no?

http://www.nf8m.com/pattern_maps/US-CA_nighttime/N-map_1030KHz.html
Click to expand...

WPHT http://www.nf8m.com/pattern_maps/US-CA_nighttime/N-map_1210KHz.html

KYW: http://www.nf8m.com/pattern_maps/US-CA_nighttime/N-map_1060KHz.html
 
You must log in or register to reply here.
Status
This thread has been closed due to inactivity. You can create a new thread to discuss this topic.
Back
Top Bottom