AM Frequency of the week--740

[davideduardo]

night site would use Salton Sea or something), but apparently they want to get off the islands.

The entire Coachella Valley has some of the worst conductivity in the world. No local AM covers the whole market... the AM news and talk station has 1140 with 10 kw, 970 with 5 kw and 1250 as well to cover it, and still they added an FM low power to fill in. There is no way to get a signal out of the valley and cover any other area well at any power.

 

[pianoplayer88key]

night site would use Salton Sea or something), but apparently they want to get off the islands.

The entire Coachella Valley has some of the worst conductivity in the world. No local AM covers the whole market... the AM news and talk station has 1140 with 10 kw, 970 with 5 kw and 1250 as well to cover it, and still they added an FM low power to fill in. There is no way to get a signal out of the valley and cover any other area well at any power.

Hmm.... then is there a site they could use that will allow them to run 50kW, cover all the areas their 1 mV/m contour now hits, while sending no more than about 0.5 to 10 mV/m @ 1 km in a swath from toward Victoria, BC clockwise around to, say, Puerto Vallarta, Mexico (and maybe enable them to run 50kW at night because they'd be protecting Canada and Mexico (except for Baja California))? (I would guess they'd be able to send more than 10mV/m in some of those directions in the day... personally I prefer that a station, when it's making a change to its facilities, not lose coverage it already has in certain directions, unless it's moving to a totally different area (and in this particular case due to the current reach of KBRT's signal, I consider that to be most of the southern California area from San Diego to Los Angeles & San Bernardino - I even have heard of it being picked up in western Arizona in the day.)

 

[radioman148]

What about 1030 XESDD in Rosarito and 1040 KURS in San Diego? XESDD sends a LOT more signal north into San Diego than the database says. Here in El Cajon 11 miles from 1040's site, the two stations both come in at about the same strength (comparable to how KNX is received in the day at my location, and I believe I've posted recordings of that previously), and most of my radios (even one with a fairly wide IF filter) have virtually no problem separating the two through most of the area, including at home.

About the only place my Tecsun PL-606 really has any difficulty is very close to 1040's transmitter site. (On the other hand, it fails miserably at separating a very faint signal (something like maybe 100 uV/m) from a first-adjacent very strong one (more like upwards of 1,000 mV/m.))

If the two stations can co-exist closely spaced in more ways than one, why couldn't the others?

It's been awhile since I've scanned the dial in Southern Cal, but obviously the dial is very crowded.

 

[pianoplayer88key]

GRRR... damn time limit for edits is WAY too short!!     (If a mod could delete the above post and replace it with this, that would be greatly appreciated.)  In fact... I think that's what I'll do from now on...  if I want to edit a post and have passed the edit time, I will just repost the ENTIRE post, with the corrections I had planned to make.

The entire Coachella Valley has some of the worst conductivity in the world. No local AM covers the whole market... the AM news and talk station has 1140 with 10 kw, 970 with 5 kw and 1250 as well to cover it, and still they added an FM low power to fill in. There is no way to get a signal out of the valley and cover any other area well at any power.

The edit time for my previous reply escaped me, but I remembered something else...

How much of a difference do you think there is between the "worst" conductivity and the "best" conductivity in the world (not including saltwater)?  For example, is it possible that 50kW into a 1/2-wave antenna around 750-900 kHz in a "worst" area may pretty much be fizzled out at 70 miles so a DXer using something like a Superradio or CCRadio in a rural area would have difficulty identifying the station, but maybe 10kW into a 1/4-wave antenna somewhere between 1200-1400 kHz in a "best" area may still have a reasonable signal on a typical car radio (so at a normal listening volume the radio's noise is equal to or less than the road noise when traveling full-speed on the highway) at, say, 300-350 miles out, also in a rural area?

Also, I can get a reasonable signal on 970 KNWZ here in El Cajon, CA.  (I suspect it'd be even considerably better if 980 KFWB's IBOC wasn't wreaking havoc on 970.)  Also, last August near midday I was able to get a fairly solid signal from KNWZ at Cameron Corners, CA - near Campo, NE of Tecate, and IIRC that's not in the Coachella valley.
If that station can be heard in south San Diego county with that solid of a signal, why doesn't it cover the entire Coachella valley?  Are most people's radios so insensitive that the signal fades into the noise so a DXer wouldn't be able to ID them even if it was a QRSS CW signal and the man-made noise & interference from other stations was below atmospheric noise, and there was no thunderstorm activity within 3,000 miles, even before they leave the valley?  Or are they so picky that they won't listen to a station any weaker than this very strong signal (760 KFMB, recorded with the PL-606, Select-A-Tenna & utility pole ground wire (which seems to act as a makeshift beverage antenna) @ my house 7.3 mi SE of their transmitter, on January 1 when it switched from 5kW to 50kW in the evening)?
On 1140, though, splatter from 10kW KSDO 6.3 miles north of me kills any chance of receiving 1140 KNWQ, and 1250 is occupied by KZER Santa Barbara, CA.

 

[stormy01]

GRRR... damn time limit for edits is WAY too short!! (If a mod could delete the above post and replace it with this, that would be greatly appreciated.) In fact... I think that's what I'll do from now on... if I want to edit a post and have passed the edit time, I will just repost the ENTIRE post, with the corrections I had planned to make.

There never seems to be enough time for editing posts. If the board owner/moderator does increase the time limit for edits, great, but until if it's a major correction I just compose on a text editor and then copy and paste. I know, it's a P.I.T.A.....

 

[cyberdad]

For the next week, I'm in our usual getaway spot on the beach at Perdido Key, FL....on the AL-FL state line, about 23 miles southwest of downtown Pensacola. This trip, I've got a rental car with an excellent radio. (Chevy Malibu...who knew?)

Anyway on the highway that runs along the beach, I'm getting three stations on 740 daytime. WMSP (Montgomery) is the strongest, as well as being the one usually heard here. I haven't been able to identify the two stations underneath, but they are both in English and one is definitely sports talk (as is WMSP). My guess is that the sports talker could be WYGM. Although most of their juice is pointed away from me, saltwater path notwithstanding.

I'm wondering if the other station...the weaker of the two behind WMSP....could be KTRH.

Any ideas?

 

[radioman148]

For the next week, I'm in our usual getaway spot on the beach at Perdido Key, FL....on the AL-FL state line, about 23 miles southwest of downtown Pensacola. This trip, I've got a rental car with an excellent radio. (Chevy Malibu...who knew?)

Anyway on the highway that runs along the beach, I'm getting three stations on 740 daytime. WMSP (Montgomery) is the strongest, as well as being the one usually heard here. I haven't been able to identify the two stations underneath, but they are both in English and one is definitely sports talk (as is WMSP). My guess is that the sports talker could be WYGM. Although most of their juice is pointed away from me, saltwater path notwithstanding.

I'm wondering if the other station...the weaker of the two behind WMSP....could be KTRH.

Any ideas?

My thought was KTRH also. I have heard it in New Orleans during the day.

 

[gar hi]

I'd say KTRH as they are sending about 13 kw in the direction of Pensacola.

They don't send much more than that toward the beach in Dunedin where I finally confirmed it as a daytime catch.

 

[cyberdad]

I'd say KTRH as they are sending about 13 kw in the direction of Pensacola.

They don't send much more than that toward the beach in Dunedin where I finally confirmed it as a daytime catch.

Makes sense. On 560, KLVI (Beaumont) is clearly audible here...along with WOOF (Dothan). So if KLVI can get here with 5kw....I'd think 13kw would be enough to propel KRTH here as well. Especially if you've been able to confirm them in Dunedin. I'll see if I can confirm them later during my week here. But frankly I'd rather hang out on the beach (or the Florabama next door) instead of in the car!

 

[Icangelp]

But frankly I'd rather hang out on the beach (or the Florabama next door) instead of in the car!

Flora-Bama Lounge? My head hurts thinking about that place. The first time we went there, I got such a hangover. Wasn't their fault, was my own. Way too old for such stupidity. Went back several times after that, and returned home with only good memories.

I hope you're eating some oysters.

 

[cyberdad]

Funny....Mrs. Cyberdad got a really bad hangover after an evening at the Florabama last year. But it wasn't her fault.

Nope. It was later determined that there was a bad batch of limes in the margaritas her brother kept buying for her! ;D

And, sorry, I'm not an oyster guy. Down here for us, it's Cuban Sandwiches (Hub Stacy's), Shrimp (Shrimp Basket), Gumbo (Sea & Suds), and Barbecue (Moe's). Little known fact....Florabama (actually the building right next door to ours) serves a surprisingly decent burger.

(apologies for the OT veer)

 

[stacker]

How much of a difference do you think there is between the "worst" conductivity and the "best" conductivity in the world (not including saltwater)? For example, is it possible that 50kW into a 1/2-wave antenna around 750-900 kHz in a "worst" area may pretty much be fizzled out at 70 miles so a DXer using something like a Superradio or CCRadio in a rural area would have difficulty identifying the station, but maybe 10kW into a 1/4-wave antenna somewhere between 1200-1400 kHz in a "best" area may still have a reasonable signal on a typical car radio (so at a normal listening volume the radio's noise is equal to or less than the road noise when traveling full-speed on the highway) at, say, 300-350 miles out, also in a rural area?

Couple of interesting questions here. Best conductivity is 50 mS over saltwater. Parts of the midwest come in at 30 mS, but measure much lower than the estimates. About a 50% reduction from the Federal M-3 estimates seems about right. The M-3 map is on the FCC website. You can see the desert areas with very low conductivity, as well as the beach regions. If a midwest 1kW makes 70 miles to the .5 contour at 15 mS, then the coverage is generally reduced proportionately if the surrounding ground is 8mS.

1/2 wave antennas, while being typically more efficient that a 1/4 wave, are not necessarily the best for combined day/night coverage. A 1/2 wave can introduce vertical skywave that puts the fade zone within the effective night ground wave signal of the station. This condition is what lead to the development of sectionalized antennas on some stations. Like WOAI. The top part of the tower is used to minimize the vertical radiation so that the fade zone occurs beyond the groundwave contour.

 

[gar hi]

Best conductivity is 50 mS over saltwater.

I thought it was 5,000.

 

[stacker]

I thought it was 5,000

You are correct.

 

[pianoplayer88key]

I thought it was 5,000

You are correct.

To give you an idea of how well stations do over saltwater, this is 1290 KZSB Santa Barbara, CA, recorded in Ocean Beach, CA, a community that's part of San Diego, CA.
I was at 32°44'29.02"N 117°14'59.66"W when I recorded it, and KZSB is about 293.157 km (182.159 mi) from there at a heading of 310.24° (reverse 128.89°.) Distance from KZSB's tower to the shoreline is about 0.784 km (0.487 mi) toward my location, or 0.65 km (0.4 mi) at the nearest approach. From my QTH to the shore was 0.655 km (0.407 mi) toward KZSB, or 0.493 km (0.306 mi) toward the nearest shoreline. (In case the distances differ from what the FCC says if you choose to query them, I plotted them using the measuring tool on Google Maps.)

It was recorded at 2:45pm local time on the 20th of Feb 2011, so should be pretty much all groundwave. Any "fading" is due to repositioning of the radio while KZSB was being recorded.
KZSB runs all of 500 watts, non-directional, in the daytime. Signal readings on the Tecsun PL-606 were 32 dBuV (RSSI - not true field strength) and 25dB SNR (max it will display on that scale), using only its built-in internal ~4.5 inch (~11.5 cm) ferrite bar antenna.

Now... does anyone have any recording of a 50kW non-directional station (directional is ok if it has a lobe, not a null, in that direction) below 900 kHz at about the same or comparable distance (mine was 182 miles), over a ground with a conductivity averaging about 1 mS or less (although it's ok if the FCC map says it's 2 in a few places, or maybe even 4 in a small portion of the path maybe a few km total), preferably using a similar radio? (It of course doesn't have to be the same model, but I definitely don't want any "cheating" by using one with a giant 7" ferrite bar, or using an outdoor beverage antenna, tuned loop, etc, to enhance the signal.) Would WFAN, WRKO, WABC, WEEI or WCBS qualify, or can someone think of any other candidates? I'm wondering whose signal would be better, the 500-watt on 1290 over saltwater, or the 50kW on, say, 660 (WFAN) or 680 (WRKO) over poor ground?

 

[gar hi]

All I can say from personal experience is that from what I remember, WFAN, WABC, and WCBS don't have as good of a signal after passing over the same distance of land with mostly a rating of 4 for conductivity.

That's roughly around 10 miles past Baltimore going in the direction of Washington.

Now that's how I remember hearing them on the car radio anyway going down 95.


If you're talking 182 miles away right along the coast, that's a whole different story.

 

[radioman148]

All I can say from personal experience is that from what I remember, WFAN, WABC, and WCBS don't have as good of a signal after passing over the same distance of land with mostly a rating of 4 for conductivity.

That's roughly around 10 miles past Baltimore going in the direction of Washington.

Now that's how I remember hearing them on the car radio anyway going down 95.


If you're talking 182 miles away right along the coast, that's a whole different story.

In the 60s when there were many less stations on AM I drove from NYC to Chicago. On my way I heard WABC all the way to just east of Pittsburgh. This was in April around 2PM (when I was in the Pittsburgh area) so the WABC groundwave did just fine back in those days.
I also remember on the same trip hearing then WNBC (660) and then at some point moving the dial just slightly to hear WMAQ on 670.
In other words no matter where I was on the 830 mile car trip between Chicago & NYC I could hear one of the NBC stations at all times.
I made that car trip many times in the 60s & 70s.

 

[gar hi]

WABC almost to Pittsburgh on a groundwave?

That's amazing considering the ground conductivity rating between there and NYC is only a 2 or a 4.

All the New York stations are gone once you get past the Washington DC metro area heading south on a car radio anyway except for the brief return of WFAN and WCBS in a small stretch on I 95 about half way between Washington and Richmond becauseof the bays to the north between there and New York.

Are you sure it was a groundwave? Then again, I wouldn't expect a skywave on that frequency in April that time of day.

The Chicago stations I could easily see making it out that far on groundwave because of the much better ground conductivity that ranges from 8 to 15.

 

[vibe]

I had the NYC clears south of Winchester VA on I-81 at midday last Oct. But the engine was off. Definitely groundwave. Almost similar distance to Pitts.

 

[radioman148]

WABC almost to Pittsburgh on a groundwave?

That's amazing considering the ground conductivity rating between there and NYC is only a 2 or a 4.

All the New York stations are gone once you get past the Washington DC metro area heading south on a car radio anyway except for the brief return of WFAN and WCBS in a small stretch on I 95 about half way between Washington and Richmond becauseof the bays to the north between there and New York.

Are you sure it was a groundwave? Then again, I wouldn't expect a skywave on that frequency in April that time of day.

The Chicago stations I could easily see making it out that far on groundwave because of the much better ground conductivity that ranges from 8 to 15.

Yes it was groundwave because I made the car trip many times in those days. Remember back then you had much less man made noise and no other stations on the frequency or nearby frequencies. WABC was the only NYC station that made it that far during the day. Probably because their transmitter was in New Jersey and of course they are/were ND. The other NYC AMs with transmitting sites in New Jersey were running DAs.