Southern California Reception

[Geographer]

While on a business trip to Southern California in April, I took a day trip between San Diego and Phoenix. I usually listened to KFI and a few stations from San Diego. The reception of KFI was good near the coast in San Diego, and seemed to good inland, but not as good as I expected from a 50KW station at 640 Khz. During the day, the signal was slightly audible just east of Yuma AZ at a distance of about 220 miles. As good as their signal is, the clears in the Midwest and Texas seem better. Stations such as WJR, WGN, WLW, CFZM, KTRH and WBAP are generally very listenable at that distance. At night, KFI gets shredded by a co-channel station about 50 miles east of La Mirada, CA. Perhaps the topography and ground conductivity are factors.

Amazingly, KALL 700 Khz from Salt Lake City was weak, but audible in the Imperial Valley to near Phoenix. I initially thought it was midday skip, but it was early afternoon in April and continuous. The distance from El Centro CA to SLC is about 600. I'm wondering if that is a typical ground wave signal from KALL, or just unusual daytime skip.

 

[radioman148]

While on a business trip to Southern California in April, I took a day trip between San Diego and Phoenix. I usually listened to KFI and a few stations from San Diego. The reception of KFI was good near the coast in San Diego, and seemed to good inland, but not as good as I expected from a 50KW station at 640 Khz. During the day, the signal was slightly audible just east of Yuma AZ at a distance of about 220 miles. As good as their signal is, the clears in the Midwest and Texas seem better. Stations such as WJR, WGN, WLW, CFZM, KTRH and WBAP are generally very listenable at that distance. At night, KFI gets shredded by a co-channel station about 50 miles east of La Mirada, CA. Perhaps the topography and ground conductivity are factors.

Amazingly, KALL 700 Khz from Salt Lake City was weak, but audible in the Imperial Valley to near Phoenix. I initially thought it was midday skip, but it was early afternoon in April and continuous. The distance from El Centro CA to SLC is about 600. I'm wondering if that is a typical ground wave signal from KALL, or just unusual daytime skip.

The ground conductivity in Southern California is not nearly as good as most of the midwest. On trips I've made to Southern California I've noticed that KFI's signal is not as good as it used to be. This seems to have occurred since their tower rebuild some years back.
Regarding KALL, they do have a great signal in the Southwest. I haven't heard them mid day, but they are one of the first stations you can hear when DXing in Southern California well before sunset.

 

[davideduardo]

The ground conductivity in Southern California is not nearly as good as most of the midwest. On trips I've made to Southern California I've noticed that KFI's signal is not as good as it used to be. This seems to have occurred since their tower rebuild some years back.

There are coastal areas with decent conductivity, around 15. But as you go inland it drops to around 8 in the San Gabriel Valley and then goes down to 4 and as low as 0.5 in the low desert and 2 in the high desert "behind" LA.

The FCC map is very generalized, and many LA stations have done local studies to get improved facilities.

https://www.fcc.gov/media/radio/m3-ground-conductivity-map

Utah, in general, has some great conductivity with 15's and even 30's in places.

 

[wildthangjim]

Is the ground conductivity better in the central valley? I lived in Bakersfield for a year in the 1990's (it seemed longer ) and the daytime GW reception seemed pretty good. For example, KNBR was one of the strongest daytime signals at 200+ miles distant and KFI was effectively a local where I lived.

 

[radioman148]

Is the ground conductivity better in the central valley? I lived in Bakersfield for a year in the 1990's (it seemed longer ) and the daytime GW reception seemed pretty good. For example, KNBR was one of the strongest daytime signals at 200+ miles distant and KFI was effectively a local where I lived.

I think the ground conductivity is better in the central valley especially if there are no mountains surrounding you. I'll bet you heard KGO pretty well too.

 

[davideduardo]

Is the ground conductivity better in the central valley? I lived in Bakersfield for a year in the 1990's (it seemed longer ) and the daytime GW reception seemed pretty good. For example, KNBR was one of the strongest daytime signals at 200+ miles distant and KFI was effectively a local where I lived.

The Central Valley ranges from conductivity of 4 in some regions to 15 in others. It is not consistent up and down the valley.

Conductivity ranges from 0.5 (Long Island, some parts of upper New England, Coachella Valley) to 30 (Great Plains, Utah plains, "wine country"). So the Central Valley ranges from "fair" to "good", without reaching the extremes to the bottom or top of the range.

The map that I linked earlier can be expanded to see the exact areas of central CA and the conductivity.

 

[radioman148]

The Central Valley ranges from conductivity of 4 in some regions to 15 in others. It is not consistent up and down the valley.

Conductivity ranges from 0.5 (Long Island, some parts of upper New England, Coachella Valley) to 30 (Great Plains, Utah plains, "wine country"). So the Central Valley ranges from "fair" to "good", without reaching the extremes to the bottom or top of the range.

The map that I linked earlier can be expanded to see the exact areas of central CA and the conductivity.

That conductivity in the Great Plains is amazing. Just checkout the daytime coverage of WNAX.

 

[cyberdad]

That conductivity in the Great Plains is amazing. Just checkout the daytime coverage of WNAX.

.....or KFYR.

David mentioned a few areas with 0.5 conductivity. Then there's the area around Pensacola, Florida, where we vacation, with a 1. Juxtaposed directly adjacent to the Gulf of Mexico, it makes for some interesting reception!

 

[Geographer]

That conductivity in the Great Plains is amazing. Just checkout the daytime coverage of WNAX.

Thanks for the great replies. I became interested in dxing ever since I was amazed to hear WLS, the Big 89 from Upstate NY. When I go on business trips, I make it a point to visit the tower sites of notable stations. Most people would probably find that silly, but it gets into your blood. I'm looking forward to hearing an all-digital AM station and analyzing the coverage.

 

[radioman148]

.....or KFYR.

I forgot about KFYR. The reason WNAX sticks in my mind is because years ago when I was in Galena, Il I heard WNAX easily on my car radio at 355 miles.

 

[radioman148]

Thanks for the great replies. I became interested in dxing ever since I was amazed to hear WLS, the Big 89 from Upstate NY. When I go on business trips, I make it a point to visit the tower sites of notable stations. Most people would probably find that silly, but it gets into your blood. I'm looking forward to hearing an all-digital AM station and analyzing the coverage.

Have you visited this site? https://www.fybush.com/

 

[boombox4]

I forgot about KFYR. The reason WNAX sticks in my mind is because years ago when I was in Galena, Il I heard WNAX easily on my car radio at 355 miles.

In my DX club years, I recall seeing a mention of KFYR as having the largest daytime groundwave coverage of any AM station in the US. I'm sure that CBK's in Saskatchewan (just a couple hundred miles north or so) is similar.

 

[davideduardo]

In my DX club years, I recall seeing a mention of KFYR as having the largest daytime groundwave coverage of any AM station in the US. I'm sure that CBK's in Saskatchewan (just a couple hundred miles north or so) is similar.

CBK is vastly greater, but it is not in the US.

KFYR, WNAX, and several other low frequency stations in Iowa, KS and the Dakotas and even OK and TX have very similar huge coverage areas. If it is below 640, 5 kw and non-directional, the coverage rivals any station in the US irrespective of power.

 

[cyberdad]

CBK is vastly greater, but it is not in the US. .

I have personally tracked CBK's daytime signal in car radios on the Trans-Canada Highway from about 20 miles into far western Ontario to the Alberta-British Columbia border. Basivally a two day drive. Much larger footprint than either KFYR or WNAX. Both of which I've also personally trcked (east-west.)

 

[Geographer]

Have you visited this site? https://www.fybush.com/

I think I may have years ago, it's a great site.

 

[gar hi]

KFI has a listenable daytime signal as far north as Santa Cruz.

And back in 1977, I remember it had a good signal midday in the summer in the central valley when we got on Interstate 5 coming from Gilroy.

 

[davideduardo]

KFI has a listenable daytime signal as far north as Santa Cruz.

And back in 1977, I remember it had a good signal midday in the summer in the central valley when we got on Interstate 5 coming from Gilroy.

That may have been the case back in the 70's, but with today's noise levels even being destructive in rural area, the useful signal is far more limited now.

 

[radioman148]

I have personally tracked CBK's daytime signal in car radios on the Trans-Canada Highway from about 20 miles into far western Ontario to the Alberta-British Columbia border. Basivally a two day drive. Much larger footprint than either KFYR or WNAX. Both of which I've also personally trcked (east-west.)

No doubt CBK is the best, but how far east did you hear WNAX?

 

[cyberdad]

No doubt CBK is the best, but how far east did you hear WNAX?

I could always hear WNAX day and night in the Twin Cities (in open noise-free areas). Going east of there on I-94, I could hear them on a decent car radio for about 30-40 miles into Wisconsin before the splatter from WKTY (580) would take over.

At my college location in southeast Iowa, our campus carrier current station was on 579. If we were off during the daytime, WNAX came through.

 

[radioman148]

At my college location in southeast Iowa, our campus carrier current station was on 579. If we were off during the daytime, WNAX came through.

That's similar to where I heard them in Galena, Il during the day.