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LOOKING TO BUY LOS ANGELES STATION.

Wow, the ground conductivity in the Coachella Valley must be absolutely terrible if a 99-watt FM does better than a 5kW and a 10kW AM! (What about 1250 KNWH? What hole is it supposed to fill?) What frequency is that FM on? I wonder if I'd get better reception of it than 970 KNWZ in El Cajon.... (I can't get 1140 KNWQ due to 1130 KSDO's splatter, though, and 1250 is occupied by KZER Santa Barbara and splatter from local 1240 KNSN. Also I was just remembering that when I was in Borrego Springs one summer day several years ago, I was getting a clear signal from 970 KNWZ with a Panasonic walkman-size radio/cassette player and Select-A-Tenna.
So the FCC map says the conductivity is "2", but what do you say it really is? Is the ground path from Santa Barbara to San Diego that much better so I can get 500-watt 1290 KZSB in Ocean Beach with a better signal than 10kW 1140 KNWQ a few miles west of Riverside on CA-60?

Also what do you mean by 830 having a worse signal than 980? I thought 830 was 50kW to 980's 5kW, and I thought the lower dial position should have less groundwave losses? Or does it have to do with 830's transmitter being so far from their COL? Last few times I've been in the L.A. area I remember receiving KLAA loud and clear at my grandma's house in San Gabriel day and night, as well as at night on the way home (down 605 or 57 (if from Hacienda Heights) and 5 through Orange county). Earlier this week I did have difficulty at night with KLAA at a friends house in northwest Moreno Valley, but that's not an area that 830's trying to serve, is it?

Of course I realize that no frequency would be available for this, but if, theoretically, there was a 50kW non-directional AM somewhere below 600 kHz using a Franklin antenna, would it cover the entire valley during the day? Or, what do you think the major limiting factor would be? Ground conductivity? Too much man-made noise? Speaking of which, what level signal in a rural area would be comparable to a 15mV/m signal (minimum I think you mentioned for L.A. area listeners) on a $5 pocket radio (whose noise floor (DXer's limit) sensitivity is, say, 2mV/m) inside a thick-walled (for example one that could survive a direct hit from Tsar Bomba) steel building with lots of equipment running in downtown L.A.? BTW so far my observation is that my radio's front ends are beginning to overload, even with a signal below 15mV/m. Amplify that signal with a big enough longwire antenna, and it'll probably overload my radio so the audio on the assigned channel is overdriven/distorted.

How much farther would you think stations would be "listenable" if all the man-made noise that exceeds atmospheric noise was reduced? IMO excessive noise levels seem, for me, to be the primary culprit for poor reception. Also something that puzzles me.... so the FCC usually doesn't license adjacents close geographically.... any idea why my radios do fine separating 1030 XESDD and 1040 KURS, both locals for me, but have difficulty digging out 1110 KDIS and can't hear 1150 KTLK with 1130 KSDO and 1170 KCBQ in the way? I would normally expect to get fair reception of 1110 and 1150, but have 1030 and 1040 stompin' all over each other.
 
I realized times have changed but KFWB was once a high rated top 40 station, so it must have reached most of LA to do this. I realize there isn't much of an audience for AM radio, but their signal must be half way decent.
 
Ron said:
I realized times have changed but KFWB was once a high rated top 40 station, so it must have reached most of LA to do this. I realize there isn't much of an audience for AM radio, but their signal must be half way decent.

When KFWB was top rated, roughly the early 60's, LA had nowhere near the urban sprawl out the San Fernando and San Gabriel valleys, the half million people in the Santa Clarita and High Desert areas were a few tens of thousands, Orange County was not part of the metro, and the market was half the population.

Even more important, the man made interference levels were much lower, meaning the useful coverage was much larger than it is today.

The signal is not good enough to compete for the only positions left for AM... talk, sports and news.
 
tfcwings said:
Wow, the ground conductivity in the Coachella Valley must be absolutely terrible if a 99-watt FM does better than a 5kW and a 10kW AM! (What about 1250 KNWH? What hole is it supposed to fill?)

1250 covers the 29 Palms area. Far the other side of the mountains and the national park. The Coachella Valley AMs are useless there.

Conductivity is worse than Long Island... guessing below 0.5.

Is the ground path from Santa Barbara to San Diego that much better so I can get 500-watt 1290 KZSB in Ocean Beach with a better signal than 10kW 1140 KNWQ a few miles west of Riverside on CA-60?

The SD to SB path is salt water... about 5000 in theoretical conductivity.

Also what do you mean by 830 having a worse signal than 980? I thought 830 was 50kW to 980's 5kW, and I thought the lower dial position should have less groundwave losses?

830 is severely directional, basically an Orange County signal that gets the Southern part of the LA County area daytime, and worse in daytime. It's transmitter is on horrible conductivity land to the east of the OC market, while KFWB is on relatively good land right at the center of the LA population.

Of course I realize that no frequency would be available for this, but if, theoretically, there was a 50kW non-directional AM somewhere below 600 kHz using a Franklin antenna, would it cover the entire valley during the day?

You realize a Franklin below 600 would be about 1700 feet high? (Two half waves, or about 520 meters). The chances of zoning that are zilch.

As to interference, remember that static and noise is amplitude modulated too, so if you amplify the signal, you amplify the ambient noise.
 
DavidEduardo said:
1250 covers the 29 Palms area. Far the other side of the mountains and the national park. The Coachella Valley AMs are useless there.

Conductivity is worse than Long Island... guessing below 0.5.

The SD to SB path is salt water... about 5000 in theoretical conductivity.

Just wondering... how much more power (in dB for example) would a station have to use in the CV to duplicate what a particular station would have over saltwater (for example, same distance to, say, the 15mV/m clear signal, or the 15µV/m fringe signal), all other factors (frequency, antenna, receiver used, etc) being the same?

830 is severely directional, basically an Orange County signal that gets the Southern part of the LA County area daytime, and worse in daytime. It's transmitter is on horrible conductivity land to the east of the OC market, while KFWB is on relatively good land right at the center of the LA population.

I thought 830 was non-directional in the daytime. If they only get the southern part of LA County area daytime, then how is it I can get a clear signal in San Gabriel? Are my Tecsun PL-380, Tecsun PL-606 or Sony SRF-59 really THAT much better of an AM radio than most radios people typically use, even though the Tecsuns block/desense badly in high RF environments? (I would have thought it would have been the other way around - a home tuner would completely trounce my ultralights, i.e. a signal a DXer would call unreadable on the ultralight even with the aid of a 4-foot air-core tuned loop would be giving the ~144dB signal-to-noise ratio that I guess consumers may look for on the home tuner using only its built-in ferrite or few-inch loop supplied with the radio.)
I guess I'm still in a fairly significant state of disbelief. :eek: Based on how I hear the L.A. and Coachella Valley signals described, I would not expect to even be able to BFO beat with their carriers here in El Cajon day OR night even with a high-end AM tuner (for example 3 front-end tuned RF stages, separate quad-conversion local oscillator and mixer, 10 IF stages, 4 24-pole IF filters, synchronous detection, 18" ferrite bar, anything else I'm forgetting) and a tuned multi-wavelength beverage antenna, yet I'm able to hear quite a few of them using just a pocket-sized Sony SRF-59 and its built-in ferrite bar antenna! Also I had thought that Long Island and northern NH & VT had the worst conductivity. You wouldn't by any chance know where I might be able to find a more accurate ground conductivity map of the USA?

You realize a Franklin below 600 would be about 1700 feet high? (Two half waves, or about 520 meters). The chances of zoning that are zilch.

As to interference, remember that static and noise is amplitude modulated too, so if you amplify the signal, you amplify the ambient noise.

Yes, I realize that - it was just a theoretical question. BUT.... what about the TV antennas in some places in the USA that are upwards of 2000 feet high??

And, yes, I do realize that about the interference. I do believe, though, that there are no FM stations with a wide enough coverage area so you can drive all day (crossing a few state lines maybe, unless you're in Texas for example) without ever having to switch to a different station (something that I personally like the AM band for, although I don't know of any California stations with coverage quite like that, unless you count driving on the parking lots disguised as freeways in L.A. while listening to KFI with the aforementioned high-end tuner+antenna system).
There's other coverage-related questions I'd like to ask... but, well... I'm just not sure how to formulate them. I just can't believe that most listening to a signal is only done when it's at or above a level that I've found is already starting to overload my radios' front ends (desensing them to weaker signals, having the modulation splatter start to spill over onto the first-adjacent (and on one it's spilling onto the second or THIRD!)), and with a big enough antenna actually can overload the detector / audio section producing a distorted/overdriven-sounding signal. What ARE the manufacturers putting in their AM sections, anyway? A diode and a capacitor (or varactor diode) and that's IT??? No wonder the AM sections on radios I've tried in stores are so bleeping deaf!!
 
tfcwings said:
I thought 830 was non-directional in the daytime. If they only get the southern part of LA County area daytime, then how is it I can get a clear signal in San Gabriel?

The San Gabriel Valley is southern LA County... the SE part, to be specific. And while KLAA is non-d daytime, the signal, quite a distance from the site, is affected by condutivity and terrain. It just does not put a heavyweight signal into the norhtern part of LA County... particularly the San Fernando Valley, the Santa Clarita area and the High Desert area.

You wouldn't by any chance know where I might be able to find a more accurate ground conductivity map of the USA?

When areas are thought to have different conductivity than predicted, then they do their own measurements and submit them to the FCC. But the official data is in the FCC map set.

Yes, I realize that - it was just a theoretical question. BUT.... what about the TV antennas in some places in the USA that are upwards of 2000 feet high??

Most of those big sticks are in rural areas outside a city. There is no such area in SoCal that is not a parkland or protected environment or in a fleight path or with close neighbors. And the fact that we are in an earthquake zone does not make building a big tower practical. A big AM stick would want to be on better conductivity coastal or near coastal land, like KNX and KFI are on. KFI could not even rebuild its half wave tower...

I just can't believe that most listening to a signal is only done when it's at or above a level that I've found is already starting to overload my radios' front ends (desensing them to weaker signals, having the modulation splatter start to spill over onto the first-adjacent (and on one it's spilling onto the second or THIRD!)), and with a big enough antenna actually can overload the detector / audio section producing a distorted/overdriven-sounding signal. What ARE the manufacturers putting in their AM sections, anyway? A diode and a capacitor (or varactor diode) and that's IT??? No wonder the AM sections on radios I've tried in stores are so bleeping deaf!!

Well, a study of literally millions of diary entries spanning nearly a decade in about 10 major markets showed that, depending on the city, about 95% of at home and at work listening happens within the 10 mV/m contour (markets outside the top 10) or the 15 mV/m contour. People don't want to listen to AM much anyway, but when they do, they want a good clear signal.
 
DavidEduardo said:
romer979fm said:
don't most major players get their station availability info from a radio web site?

... or eBay?

Geee, no wonder I never had a nibble, I should have tried Craig's List....
Well you got to give the guy credit, well maybe not.
LOL
 
DavidEduardo said:
The San Gabriel Valley is southern LA County... the SE part, to be specific. And while KLAA is non-d daytime, the signal, quite a distance from the site, is affected by condutivity and terrain. It just does not put a heavyweight signal into the norhtern part of LA County... particularly the San Fernando Valley, the Santa Clarita area and the High Desert area.

I'll have to check when I go to Tulare, CA, over Memorial Day Weekend, but I thought I was able to hear KLAA there in the day last time I was there over Xmas.
How good is KLAA's signal, in your opinion, in the COL?

Well, a study of literally millions of diary entries spanning nearly a decade in about 10 major markets showed that, depending on the city, about 95% of at home and at work listening happens within the 10 mV/m contour (markets outside the top 10) or the 15 mV/m contour. People don't want to listen to AM much anyway, but when they do, they want a good clear signal.

Ok, then about how much stronger does the signal get (above, let's say the 15 mV/m contour) before someone with a good ear may begin to detect traces of modulation splatter on the first-adjacent channel (or IBOC hash if the station uses it) on a fairly cheap consumer radio like the Sony SRF-M37W (assuming you're outdoors as far away from electrical interference as is practically possible), or it begins to desense to weaker signals on nearby channels, or a hardcore DXer might begin to consider calling the station a pest?
 
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