DX OPPORTUNITY on 670, 720 and 780 in Chicago

[CADXER]

According to several AM DX list reports, AM 670 WSCR, 720 WGN and 780 WBBM will go silent this Saturday moring, March 10, 2012 between 2:00 - 5:00 am Central Time. This downtown has been apparently requested by the engineers at WSC/WBBM in order to conduct maintenance work.

This presents a great opportunity for the local DXers to hear some new stations on the otherwise unusable frequencies. These stations seldom go off the air. In my 30+ years of DXing I can only remember AM 670 WMAQ off the air only once.

Several DXers are trying to arrange special broadcasts from other stations on the frequencies while the Chicago stations are off the air.

 

[radioman148]

According to several AM DX list reports, AM 670 WSCR, 720 WGN and 780 WBBM will go silent this Saturday moring, March 10, 2012 between 2:00 - 5:00 am Central Time. This downtown has been apparently requested by the engineers at WSC/WBBM in order to conduct maintenance work.

This presents a great opportunity for the local DXers to hear some new stations on the otherwise unusable frequencies. These stations seldom go off the air. In my 30+ years of DXing I can only remember AM 670 WMAQ off the air only once.

Several DXers are trying to arrange special broadcasts from other stations on the frequencies while the Chicago stations are off the air.

Thanks for the info. Please let us know if you find out what other stations may be broadcasting on those frequencies at that time.

 

[ercjncpr]

no good in southern California with KIRN 670 Simi Valley, KDWN 720 Las Vegas and 780 KKOH in Reno. But I hope you guys in the east have good luck

 

[cd637299]

Living near Miami, with a local on 670 (not to mention a Cuban there too), a strong local (and Cubans) on adjacent 710, and a fairly strong adjacent 790, welllllllllll.......

I sometimes hear Radio Coro (Venezuela) on 780 about as often as WBBM. 720 might be interesting if I can null well. However it'll be 3-6am EST....I plan to sleep this off.

Folks in the east....this could be your chance for li'l 250 watt WRZN Hernando FL on 720! It's now a talk station, and likely off the bird, so maybe only on the hour & half-hour might you hear ID, dual with WDVH 980 Gainesville.

cd

 

[CADXER]

Here is what was heard in the past by me in the Chicago area, when some these stations went off the air:

670 - the only station I managed to hear back in 1983 was a station from Cuba. Since then I have not heard WMAQ/WSCR of the air.

720 - Venezuela (YVQE) and Mexico (XEDE) heard here in the past when WGN was off. Also CHTN from Canada was heard in 2005, but they are no longer on the air.

780 - the only station with WBBM off that I heard was KROW from Reno, Nevada

Here are some targets from Saturday morning:

670 - KBOI the 50 kW station from Boise, Idaho is one station that I will be trying to hear. Unfortunately their nightime signal has a deep null towards Chicago making reception difficult. However there is a a test being scheduled during the WSCR silent period, where KBOI will send out a Morse Code IDs for one minute using their daytime non-directional pattern. The code IDs are supposed to be broadcast at 2:08 and 2:38 am Central Time. Hopefuly these will make it to Chicago.

I expect that Cuba will dominate this frequency. Other possibilities are KLTT Colorado and WWFE Florida

720 - preliminary special test from KOTZ in Alaska is scheduled between 3:00 - 3:30 am CST, but it will be a miracle if it makes it to Chicago. Good chance to try for KDWN Las Vegas. Also KSAH from Texas is a possibility.

780 -KKOH from Reno is a possibility. There are also two stations in Maine (WXME and WTME) that are possible. Alos ZBVI from Virgin Islands which signs on at 3:30 am could be another target.

Reception of any stations will depend a lot on the conditions that day considering that a huge solar storm is in effect currently.

Good luck to all trying to hear new statios on these frequencues.

 

[radioman148]

Thanks for the "heads up" CADXER!

 

[nd2023]

You might be able to hear some weak southern stations on those frequencies due to the solar storm. It's truly a rare opportunity with 3 clear channel AMs going off the air during a solar storm.

 

[Schroedingers Cat]

Are they installing filters in the transmitters and antenna systems? Otherwise, why not WLS and others?

 

[Lawppy]

Will definitely listen for this! But electrical buzzing destroys the lower AM band in my neighborhood so any reception will become even more difficult!

 

[CADXER]

Are they installing filters in the transmitters and antenna systems? Otherwise, why not WLS and others?

Not sure what the reason is. All I know is that it was initiated by the WBBM/WSCR engineering, so they must be doing something to their tramsitter(s). WGN is most likely included because it is so close to the other two transmitters. Their stick is only 1 mile north of WBBM. WLS is not part of it because their stick is quite far away. The other Chicago 50 kW (WMVP) stick is actually closer than WLS to the three stations in question.

As Nick notes, the most likely stations to be heard are southern based ones due to the solar storm currently in progress.

 

[CADXER]

Latest news is that actual downtime will be between 2:00 - 4:00 CST and not 2:00 - 5:00 CST.

 

[davideduardo]

Are they installing filters in the transmitters and antenna systems? Otherwise, why not WLS and others?

My suspicion would be that they are doing a new base impedance measurement on one of them, perhaps in conjunction with broadbanding or suspicions of change, and they are concerned with the overall RF environment and induction of the other two signals as they are so close to the tuned frequency of any one of them.

 

[Tom Wells]

This will be interesting as I've never heard any of them really off either.
I'll make a point of heading out to the car between those hours.
Inside work is more RF noise generating crap than you can imagine.

Very likely even when one of the three is off air, the proximity of the others makes it
a real trick to balance and tune L and C for best linearity since the others being on air
and nearby in frequency results in some current flow.

I suspect all will retune their traps for the others' frequencies, clean roller inductors, retune the overall
ATU using an analyzer that will leave all three sounding crisper since it can be tuned up in a "receiver-like"
alignment situation for weak signals. It can be easier to find the critical point with dx signal conditions than
when 50 kw is present. You can't clean, wiggle and tighten connections either.

I'd love to hear WGN come back on air with a recording of what THEY heard on 720 while tuning up for 720
with their particular antenna. Will THEY hear something amazing, or just sidesplat from 710/730?

WSCR had some real problems making iboc behave; it has been off for months, 50/50 chance WSCR 670 will come back with iboc.
I'd like to hope they are done with it, but being CBS, they'll probably be trying again, and this
very action may be another attempt to get the 670 antenna linearity acceptable.
I think nearby wiring, development, and power distribution
has created a little pocket of complex RF impedances that do not play well with hybrid analog/digital AM, as
they had a special unique audio peak futzing that came back repeatedly and made the analog host signal
have a "lisp". HD decode still seemed to work, just sounded extra-awful on analog radios while WBBM
made huge improvements in the analog product even with iboc whiskers.
It was unusual. They did get it tuned (or cleaned) away more than once and it always returned within days..



If they're smart, they'll all be looking at cleaning and reseating any point where RF impedance grows.

 

[asugeorge1]

Heard the KBOI 670 AM DX test at 2:08 A.M. Central Time down here in Phoenix, AZ. Was interesting because KBOI powered up around 2:07 with a program already in progress, and then there was a whooshing sound that lasted a few seconds and replayed for nearly a minute. The aforementioned Morse Code did not start until 2:09 A.M. with first a high Morse Code tone, and then a lower tone Morse Code. Came in relatively clear down here, and KBOI is not a usual visitor here in the desert with their strong night-time null to the east and south.

Anyone else heard the KBOI Morse Code test back there in Chicago or any points east?

 

[w9wi]

The KBOI test was heard in Iowa.

I was trying here near Nashville but not even a hint.

 

[audioguy]

I was a little late for the 2:08 KBOI test and did not hear anything at 3:08. What I heard on all three frequencies was Spanish language programming. On 670 I think I was hearing Cuba with a 1 kHz tone in the mix-- could that be a South American? On 720 what I heard appeared to be regional Mexican music peaking to the SW. I never heard a trace of anything else; that signal was very strong. On 780 I also heard music. I'll be interested to read what others in the Chicago area were able to hear. By the way, WBBM jumped the gun and came back on with little fanfare around 3:45 according to my alarm clock.

Wouldn't it be great if these stations would go occasionally go silent on a regular basis, like in the old days when they used to do that so listeners could test the performance of their radio "sets"?

 

[schmave]

I was a little late for the 2:08 KBOI test and did not hear anything at 3:08. What I heard on all three frequencies was Spanish language programming. On 670 I think I was hearing Cuba with a 1 kHz tone in the mix-- could that be a South American? On 720 what I heard appeared to be regional Mexican music peaking to the SW. I never heard a trace of anything else; that signal was very strong. On 780 I also heard music. I'll be interested to read what others in the Chicago area were able to hear. By the way, WBBM jumped the gun and came back on with little fanfare around 3:45 according to my alarm clock.

Wouldn't it be great if these stations would go occasionally go silent on a regular basis, like in the old days when they used to do that so listeners could test the performance of their radio "sets"?

This almost undoubtedly was KSAH from San Antonio. They usually pull their signal in dramatically to the northeast to protect WGN; did they go to daytime power for this test? Forgive me if this was answered earlier.

 

[Buckeyes2001]

I was a little late for the 2:08 KBOI test and did not hear anything at 3:08. What I heard on all three frequencies was Spanish language programming. On 670 I think I was hearing Cuba with a 1 kHz tone in the mix-- could that be a South American? On 720 what I heard appeared to be regional Mexican music peaking to the SW. I never heard a trace of anything else; that signal was very strong. On 780 I also heard music. I'll be interested to read what others in the Chicago area were able to hear. By the way, WBBM jumped the gun and came back on with little fanfare around 3:45 according to my alarm clock.

Wouldn't it be great if these stations would go occasionally go silent on a regular basis, like in the old days when they used to do that so listeners could test the performance of their radio "sets"?

This almost undoubtedly was KSAH from San Antonio. They usually pull their signal in dramatically to the northeast to protect WGN; did they go to daytime power for this test? Forgive me if this was answered earlier.

Only thing is there is another 720 right across the border from El Paso in Ciudad Juarez (XEJCC) running 25kW. I would think KSAH running 10kW at night would cause interference to XEJCC. If you heard 'En Chihuahua...' followed by ranchera songs and announcements between songs on 720 then it would be XEJCC. If not, then I'd say it was KSAH.

 

[K4WRF]

Are they installing filters in the transmitters and antenna systems? Otherwise, why not WLS and others?

My suspicion would be that they are doing a new base impedance measurement on one of them, perhaps in conjunction with broadbanding or suspicions of change, and they are concerned with the overall RF environment and induction of the other two signals as they are so close to the tuned frequency of any one of them.

One also has to wonder if there was (or is) some consideration to co-location of 670 and 780 facilities. Both those large tracts of land they occupy are prime locations. Someone at CBS might be seeing those $$$$..... 780 sits at the intersection of two major freeways.

All speculation of course.

Best regards,
w/

 

[davideduardo]

Only thing is there is another 720 right across the border from El Paso in Ciudad Juarez (XEJCC) running 25kW. I would think KSAH running 10kW at night would cause interference to XEJCC. If you heard 'En Chihuahua...' followed by ranchera songs and announcements between songs on 720 then it would be XEJCC. If not, then I'd say it was KSAH.

XEJCC is theoretically 25 kw days, 500 nights. KSAH is less than 1 kw at night, and directional.