Places where the FM dial is blank

[ftballfan]

I've been in a few places in northwest Lower Michigan where the AM scan stops at nothing. The soil conductivity is awful. Even the 50kW on 1210 only breaks the squelch for about 20 miles.

In contrast, doing an FM scan brings only a few short of 100 stations.

Manistee County away from Lake Michigan would probably fit (on AM)

 

[AKDXer]

Another place where you can be driving with the radio on "seek" with it stopping at absolutely nothing (on FM) is around Chena Hot Springs, AK, about 70 miles (my estimate) from Fairbanks. Radio-Locator lists all the big Fairbanks stations as being weak, but obviously they don't stop the "seek"; you'd need an outdoor Yagi or something to hear them.

Places here in Alaska like Anchorage and Fairbanks are unique in that you drive out of town (or, should I say, beyond the range of their radio stations) and you lose them all at once and it's pretty much nothing, unlike many places where the dial gradually changes.

 

[mimo]

Another place where you can be driving with the radio on "seek" with it stopping at absolutely nothing (on FM) is around Chena Hot Springs, AK, about 70 miles (my estimate) from Fairbanks. Radio-Locator lists all the big Fairbanks stations as being weak, but obviously they don't stop the "seek"; you'd need an outdoor Yagi or something to hear them.

Places here in Alaska like Anchorage and Fairbanks are unique in that you drive out of town (or, should I say, beyond the range of their radio stations) and you lose them all at once and it's pretty much nothing, unlike many places where the dial gradually changes.

That's what FM was like in Canada in the 80's and early 90's. Once you got outside the major cities you could drive for hours without any FM radio at all. The stations all faded at once. In the more populated areas, you could have areas where the dial did change, but in many provinces, you could drive for several hours with absolutely nothing. When I first came to the U.S. as a teen, I was surprised to learn you could be in one town and hear an FM station from another. I didn't even know that was possible. There was nothing in my Canadian experience to suggest you could do that. Not that any one my age listened to FM back then any way.

 

[davideduardo]

That's what FM was like in Canada in the 80's and early 90's. Once you got outside the major cities you could drive for hours without any FM radio at all.

It is indeed interesting to recall how the FM band grew to what it is today.

When I put my first FM on the air in 1966, there was no other FM station in the entire country.

You could go from 88 to 108 and hear nothing.

I had once DXed the closest FM, 800 miles away in another nation. But I never heard it again.

When we hit the "plate on" switch there was nothing else on the band. Now, that same market has over 40 FM stations, so many that it is hard for any to make money.

 

[pianoplayer88key]

David, speaking of "hard…to make money", I was thinking of something recently. If I am guessing right, "share" in a given market works like ... there's a total of 100 share available. (I'm guessing that day parts, age groups, etc. throws another variable into it too, but I'm simplifying it for now.) So, if, for example, there are 40 FM stations, 35 AM stations, and 25 TV stations in a given market (not counting multicast streams), that would be a total of 100 stations in that market. In that case, I'd consider any station getting a "1" share (total share divided by number of stations: 40+35+25=100 ; 100/100=1) to be doing "good enough" for the market. BUT... where does "making enough to pay the bills" come in? I'd guess in a crowded market like that it'd need a higher share. :/ (And in my opinion, if there's that many stations in a market so that it works out that way, needing to book more than the "average", then I think there's too many stations in that market, or at least too many trying to compete on the same or similar format.)

Now speaking of blank spots on the dial ... I wonder where, either in the USA, or anywhere on the surface of Earth (not in any attenuating structure) you would have below-30 MHz as empty as possible? For example, if you used a DC to 30 MHz spectrum analyzer with an elaborate antenna array throughout the day and night ... I'm sure you wouldn't have a completely empty dial, but where might you have the overall signal strengths be the lowest, and the strongest / peak signal being the weakest? Is there any place, for example, where you'd never see a skywave over 100 µV/m (even for like 5 seconds once a month) or a groundwave over 10 µV/m? Or does that never happen?

 

[davideduardo]

I'd guess in a crowded market like that it'd need a higher share. :/ (And in my opinion, if there's that many stations in a market so that it works out that way, needing to book more than the "average", then I think there's too many stations in that market, or at least too many trying to compete on the same or similar format.)

The stations that get ad buys are the ones that are near the top of the audience ratings. Even if ads are bought without the use of ratings, clients learn which stations have enough listeners to bring in business.

The stations that don't have a responsive audience or a high rating will not make money. Sometimes in the case of stations with small niche markets, the audience may be responsive but not highly rated. That is the case with ethnic stations or religious ones. Where I was, in Ecuador, there are no such smaller groups so the ratings performers made money and the little stations subsisted on a few accounts or off the funds of the owner. As an example, in Quito, there were at the time nearly 50 stations and I had 4 of them... yet those 4 took nearly 50% of the total billing in the market.

 

[Ai4i]

And WOCN 1450, Miami, keeps on punching away!

 

[AKDXer]

@Mimo, I had to laugh, but I can imagine. For me, it was "Wow, you can drive places in Alaska and still have radio the whole way?" (Even though the dial changes).

@DavidEduardo, where was this?

 

[davideduardo]

@Mimo, I had to laugh, but I can imagine. For me, it was "Wow, you can drive places in Alaska and still have radio the whole way?" (Even though the dial changes).

@DavidEduardo, where was this?

Quito, Ecuador. I owned stations there from 1964 until 1971. "The two mile high city"

 

[AKDXer]

Oh wow. I would never have thought. That must have been a unique experience!

 

[mimo]

@Mimo, I had to laugh, but I can imagine. For me, it was "Wow, you can drive places in Alaska and still have radio the whole way?" (Even though the dial changes).

@DavidEduardo, where was this?

AM was like that...with a few spots in the rockies and B.C. being empty for anywhere from a few minutes to an hour, you could go across country and have radio the whole way. In fact you could, and still can, drive from Calgary to Winnipeg and there is one station that will stay in the whole trip. It just gradually gets stronger and then fades back to the same level it was in Calgary. That would be CBK 540 and the signal in both cities is quite good. FM was really in it's infancy still back then. Some cities had stations going back to the 60's, but they were co-owned with big AM stations who covered the operating expenses for both for a long time. In the late 80's you'd have one FM in each market that was always ranked number 3, maybe another in the top 10, and the remaining 8 or 9 stations were all AM. The other FMs had very small audiences, and made up the bottom of the list. There were very few, if any stand-alone FMs, but there were a few stand alone AMs that did very well. Calgary had one stand alone FM, Which at the time was CKIK 107.3, and they were consistently number 3 in the market. Even the station which has been at the top of the ratings there for most of this century, country 105, (CKRY) was a bottom feeder until country started to disappear of the AM band in the mid to late 90's. If you found FM in a town of under 50,000 people, it was most likely a CBC station.

 

[b-turner]

I can tell you a few spots where there is nothing on the AM or FM band.

Sanderson, Texas is too far away to receive any signal, and it is that way in much of the county. Drive down to Big Bend National Park and there's nothing.

I came in to Oregon from out of Nevada. You went miles with nothing on the AM and FM. Even the little LPFM in Paisley, Oregon ran a liner early on saying without KPAI, all you got was ssshhhhh. Not even a translator! You have to reach Silver Lake or Christmas Valley and even then it's a couple of translators and you can pick up an AM Sports Talk from Bend, I think. If I recall, the only station you could get in Fossil, Oregon was the LPFM there and it's negative HAAT meant you went over the first big hill and the dial was blank again.

 

[Ai4i]

Quito, Ecuador.
I owned stations there from 1964 until 1971.
"The two mile high city"

Do you have any good stories about "The Voice of the Andes" in Quito?

BTW...No one has brought this up, but...do tunnels count for this discussion?
The radio silence within them can be truly deafening!

 

[davideduardo]

Do you have any good stories about "The Voice of the Andes" in Quito?

When I first got to Quito in early 1964 I was a guest presenter for several months on the HCJB DX Mailbag show, discussing MW DX. But shortly thereafter I bought the CP for my own station and did not have the time.

Two years later, I was building my 4th station, an independent FM and a friend told me several of the HCJB engineers had FM experience. One had been a design engineer with one of the major US equipment manufacturers until he got the call to join HCJB. Those engineers helped me design (OK, they designed, I watched and learned) an FM transmitter that could be built from available parts at local distributors. I built the transmitter, and it went on as the first independent FM in the country.

Otherwise, the HCJB operation was fairly low profile locally, but I found the people very nice and generous of their time and advice.

 

[Ai4i]

One had been a design engineer with one of the major US equipment manufacturers until he got the call to join HCJB.

In 1951, HCJB engineer, Clarence Moore (W9LZX), invented the cubical quad antenna by stretching open a folded dipole in an effort to deal with coronal discharge in the thin, two kilometer high atmosphere.

 

[davideduardo]

In 1951, HCJB engineer, Clarence Moore (W9LZX), invented the cubical quad antenna by stretching open a folded dipole in an effort to deal with coronal discharge in the thin, two kilometer high atmosphere.

Mr Moore was one of the kind folks that helped me launch HCTM1!

Another story, from around 1966, was that RCA built some 100 kw SW transmitters, but could not get them to work, particularly the frequency agile tuning system. They gave several to HCJB on the condition that any design changes would become RCA's property. HCJB made them work, putting them in service at the Pifo site where they ran until the upgrades to 250 kw and 500 kw later on.

 

[wildthangjim]

Now speaking of blank spots on the dial ... I wonder where, either in the USA, or anywhere on the surface of Earth (not in any attenuating structure) you would have below-30 MHz as empty as possible? For example, if you used a DC to 30 MHz spectrum analyzer with an elaborate antenna array throughout the day and night ... I'm sure you wouldn't have a completely empty dial, but where might you have the overall signal strengths be the lowest, and the strongest / peak signal being the weakest? Is there any place, for example, where you'd never see a skywave over 100 µV/m (even for like 5 seconds once a month) or a groundwave over 10 µV/m? Or does that never happen?

I wonder what the dial is like at the South Pole in midsummer? I understand the RFI at the base itself precludes anything from getting through, but if you moved away from the base, would you hear anything?

 

[crainbebo]

Surprised you couldn't get Klamath Falls, Bend or Boise FMs along that stretch briefly. Surely they would fade in and out over the mountains often. Would be a great stretch of highway to listen for E-skip or meteor scatter.

 

[davideduardo]

I wonder what the dial is like at the South Pole in midsummer? I understand the RFI at the base itself precludes anything from getting through, but if you moved away from the base, would you hear anything?

For FM, not much of a chance. For AM, maybe one of the best places in the world... better than Newfoundland or northern Scandinavia. Even with limited hours of darkness, the skip from areas that are dark might produce interesting equivalents to "sunset skip"-

 

[jim-satx]

I can tell you a few spots where there is nothing on the AM or FM band.

Sanderson, Texas is too far away to receive any signal, and it is that way in much of the county. Drive down to Big Bend National Park and there's nothing.

Must be some interesting nighttime AM DXing in Sanderson and Big Bend with no locals to block anything.