AM Frequency of the Week: 580

[Schroedingers Cat]

I'm going to guess that KMJ was easier duty for distant points east before they became a 50kw blowtorch with a much tighter DA.

I'm sure you're right. They come in very well on the Hawaii SDRs so they have a major lobe pointed out to the Pacific.

According to BL-1717, it was 5000 watts nondirectional full-time from a 138 degree tower.

https://www.fccdata.org/?lang=en&appid=314686&facid=26923

So that could have been heard a lot all over the contiguous states at Night.

http://licensing.fcc.gov/cgi-bin/prod/cdbs/forms/prod/getimportletter_exh.cgi?import_letter_id=43255

Consider that at the time it was authorized, the West was sparsely populated and there were few cochannel stations for hundreds of miles, it was 5 U1 in WRTH notation. Besides KXSP (WOW) 590 and KCSP (WDAF) 610, there are very few Class III stations authorized at 5 U1. WWJ 950 tried with monthly STA renewals in the 1940s, arguing that their DA cut off too much of the market, but eventually had to be 5 U2, with 1 kW equivalent nulls toward WPEN and KPRC.

Most of the Class III stations which are still nondirectional at Night are at the 500 or 1000 watt power level they were authorized circa 1940.

 

[MichaelTheZ]

I decided to head out to the Chicago lakefront to DX at 8 PM, and lo and behold, CKWW Windsor Ontario was there on 580, a new one for me. I now have 8 stations on 580 which is my maximum.

I also did a mini bandscan near 580:

580 CKWW Windsor
590 WKZO Kalamazoo
600 WMT Cedar Rapids
610 WTVN Columbus
620 WTMJ Milwaukee
630 CFCO Chatham, ON
640 WMFN Peotone, IL

So as you can see only CKWW was out of the ordinary.

 

[radioman148]

I decided to head out to the Chicago lakefront to DX at 8 PM, and lo and behold, CKWW Windsor Ontario was there on 580, a new one for me. I now have 8 stations on 580 which is my maximum.

I also did a mini bandscan near 580:

580 CKWW Windsor
590 WKZO Kalamazoo
600 WMT Cedar Rapids
610 WTVN Columbus
620 WTMJ Milwaukee
630 CFCO Chatham, ON
640 WMFN Peotone, IL

So as you can see only CKWW was out of the ordinary.

Nice catch on CKWW

 

[schmave]

I decided to head out to the Chicago lakefront to DX at 8 PM, and lo and behold, CKWW Windsor Ontario was there on 580, a new one for me. I now have 8 stations on 580 which is my maximum.

I also did a mini bandscan near 580:

580 CKWW Windsor
590 WKZO Kalamazoo
600 WMT Cedar Rapids
610 WTVN Columbus
620 WTMJ Milwaukee
630 CFCO Chatham, ON
640 WMFN Peotone, IL

So as you can see only CKWW was out of the ordinary.

WTVN in Chicago never fails to surprise me. It's quite a bit west of their main nighttime lobe which basically blasts up toward Toledo, Detroit and beyond. Great catch!
Looking forward to the 610 thread when it comes up. Now back to regular programming ...

 

[MichaelTheZ]

WTVN in Chicago never fails to surprise me. It's quite a bit west of their main nighttime lobe which basically blasts up toward Toledo, Detroit and beyond. Great catch!
Looking forward to the 610 thread when it comes up. Now back to regular programming ...

Thanks... when I'm right on the lakeshore I can hear a number of stations like that. CFCO doesn't point in my direction either but it was coming in quite well. And several Toronto stations sound nearly local right on the lakeshore.

 

[Schroedingers Cat]

CFCO may be on Day Pattern. Big lobe to the West.

CKWW might be on nondirectional STA, as it's been weaker to the North lately.

The WTVN Night Pattern has a broadside pattern component, and the field above the horizon might exceed the horizontal close in. Also, the towers are all different heights, which might also make the field above the Horizon greater. I wish that Carl Smith was still alive to tell us more about the design. Did they just happen to have the various towers of different heights because of WW II availability problems, or was it painstakingly designed that way on purpose? Seems like WTVN was Carl Smith's crowning achievement, as WXYT was to Glen Clark.

The old WWJ pattern had a 186 degree tower, which had a null at a certain angle above horizontal, which gave it a useful skywave in places 100-200 miles away, where the pattern was essentially nondirectional. The new WWJ pattern uses different height towers to protect WNTD, but has a shallow null and a decent ground wave in the azimuth direction at zero elevation toward WNTD.

 

[cyberdad]

WTVN in Chicago never fails to surprise me. It's quite a bit west of their main nighttime lobe which basically blasts up toward Toledo, Detroit and beyond. Great catch!
Looking forward to the 610 thread when it comes up. Now back to regular programming ...

WTVN around here never fails to surprise me either. I've only heard it at my location when it was on non-directional STA a while back. CKWW, of course is also a nice catch, so my congratulations to @MichaelTheZ! Well done!

 

[Schroedingers Cat]

My old DOS based Radiosoft AMR Software showed the AM patterns at various elevation angles. If I can find an old computer that had this on it, I could look up the WTVN pattern, which might explain it.

 

[Steve Green NEPA]

Day and night in the den (I don't listen to talk radio anymore) it's the loud drone of WHP Harrisburg. They are still going great guns in the ratings, years after Rush Limbaugh.
We;re just about equidistant as well as co-linear along I-81 between Harrisburg radio and the wife's former teen station WARM in Scranton -- once called The Mighty 590.
One stray SSS here, in came WCHS Charleston WV. (WCHS is a pretty bigg omni daytimer ; some of you folks may wanna try for them at SRS to add another WV catch aside from WWVA, hi).
Not too bad, eh? Only two 580 stations total, but both with alliterative calls.
580 seems like a ripe 'regioanl' camping spot for SRS-SSS catches.

Back in the retro days of Queens NYC, one late sunrise brought in a quick 'WIBW' for three of us. That might be another goodie for Easterners. I don't believe 580's spectrum has changed that much vis-a-vis a lot of frequencuies have.

 

[Schroedingers Cat]

WARM 590 was often the first station to play local East Coast "garage band" and other established East Coast artist singles. They hoped it would be heard and become a hit in NYC. Quite a few Surveys are on ARSA.

 

[cyberdad]

WARM 590 was often the first station to play local East Coast "garage band" and other established East Coast artist singles. They hoped it would be heard and become a hit in NYC. Quite a few Surveys are on ARSA.

Aren't they now country?

590 is an interesting channel for the drive from my local area to the east coast. I'll get into that next week. Don't touch that dial!

 

[davideduardo]

Look on Radio Locator to see the contours of CKWW with 500 watts vs. WTCM with 50000 watts. They're not as much different in areas covered as you might expect.

One word: Sand.

(They should rename the Sleeping Bear Dunes as the "Sleeping Signal Dunes)

 

[Schroedingers Cat]

One word: Sand.

(They should rename the Sleeping Bear Dunes as the "Sleeping Signal Dunes)

If you look through the applications for WTCM, WCCW, and WOOD upgrade Construction Permits online, on some you can find the DA Proofs of Performance, which show that in the 8 mS/m areas on M-3, the MEASURED RADIAL SEGMENTS have a lot of 0.1 mS/m segments, and none higher than 3 mS/m or so, and that is rare. At the old WCCW LIC/present STA site, you could probably be 50000 watts nondirectional with measured radials, but it would still probably be a struggle to hear it in Frankfort. Even many of the 2 mS/m M-3 area radials are lower.

Speaking of 0.1 mS/m, there is an application for the 1580 in Patchogue, NY (On Long Island) (I think it's that one) that shows a radial where all the measured points are WELL BELOW the 0.1 mS/m ground wave curve.

 

[radio 208]

From Central CA...Well needless to say, It's KMJ day and night. Something Interesting to ponder. I live about 10 miles due west of their 4-50KW towers on the same street. Have heard I might get an equivalent 200KW at my location? David, Frank, anyone? They have a tight westerly pattern.

 

[radioman148]

From Central CA...Well needless to say, It's KMJ day and night. Something Interesting to ponder. I live about 10 miles due west of their 4-50KW towers on the same street. Have heard I might get an equivalent 200KW at my location? David, Frank, anyone? They have a tight westerly pattern.

Does the signal overload any of your radios?

 

[cyberdad]

One word: Sand).

That four-letter word also explains why 50kw CBK is audible from just West of Kenora, Ontario to the Canadian Rockies, while 50kw WFLF on th4 same channel (admittedly directional), only manages to cover about 80 percent of the Florida peninsula.

 

[Schroedingers Cat]

From Central CA...Well needless to say, It's KMJ day and night. Something Interesting to ponder. I live about 10 miles due west of their 4-50KW towers on the same street. Have heard I might get an equivalent 200KW at my location? David, Frank, anyone? They have a tight westerly pattern.

Well, there's the Theoretical, Standard, and Augmented Patterns. And there's the old Class B and D minimum efficiency (282 mV/m @ 1 kW @ 1 km), the International Agreement efficiency (300 mV/m @ 1 kW @ 1 km), and 1/4 wave monopole efficiency (308 mV/m @ 1 kW @ 1 km based on 120 1/4 wave radials and 1 ohm loss (I think that's it)).

KMJ Pattern.

https://www.fccdata.org/?lang=en&facid=26923&appid=587459&tabs=74648

The augmented and standard maximum IDF is 6495 mV/m @ 1 km at 270 degrees, due West.

Using the International Agreement efficiency, the maximum would be (6495/300)^0.5=468.7225 kW.

I'll let the rest of you discuss which pattern and efficiency standard to use. If you wanted to use the isotropic efficiency (iERP) of 173.2 mV/m @ 1 kW @ 1 km, it would be much greater still, but not of much value in the real world, as there is no such thing as an isotropic radiator. Oscillating molecular dipole radiation wouldn't even be isotropic.

 

[jim-satx]

From NW San Antonio:

Day: XELRDA, 129 miles to my SW, comes in at almost local strength. I am able to null it pretty well by aiming NW/SE.

Sunset: WIBW can be heard weakly in the partial null.

Night: XELRDA is most dominant overall but has a choppy signal due to skywave/groundwave cancellation. WIBW is in the mix to varying degrees and occasionally takes over. Aiming E/W, I often hear KJMJ, but it has long fades. On rarer occasions, KRFE in Lubbock, TX, and XEAV in Tlaquepaque will make appearances.

Sunrise: XEAV is stronger and regularly mixes in with XELRDA and WIBW when it goes to day power. To the NW, KRFE usually comes up with a listenable signal for a while at day power.

DX/Retro: I've heard KUBC in Montrose, CO, and XEFI in Chihuahua once each, both a few years back.

 

[Schroedingers Cat]

Well, there's the Theoretical, Standard, and Augmented Patterns. And there's the old Class B and D minimum efficiency (282 mV/m @ 1 kW @ 1 km), the International Agreement efficiency (300 mV/m @ 1 kW @ 1 km), and 1/4 wave monopole efficiency (308 mV/m @ 1 kW @ 1 km based on 120 1/4 wave radials and 1 ohm loss (I think that's it)).

KMJ Pattern.

https://www.fccdata.org/?lang=en&facid=26923&appid=587459&tabs=74648

The augmented and standard maximum IDF is 6495 mV/m @ 1 km at 270 degrees, due West.

Using the International Agreement efficiency, the maximum would be (6495/300)^0.5=468.7225 kW.

I'll let the rest of you discuss which pattern and efficiency standard to use. If you wanted to use the isotropic efficiency (iERP) of 173.2 mV/m @ 1 kW @ 1 km, it would be much greater still, but not of much value in the real world, as there is no such thing as an isotropic radiator. Oscillating molecular dipole radiation wouldn't even be isotropic.

Correction. Make that squared, ^2, not square root, ^0.5.

 

[radio 208]

Signals don't overlap with KMJ...Just very strong. Thanks.