Not Much Directional Null Towards Co-Channel Class A

[ajaynejr]

How can it be that some co-channel DA-N and DA-2 AM Class A's (1-B's) don't have that much of a nighttime null towards the other.

Examples: WTIC Hartford towards KRLD Dallas (1080). And in Canada, CFRB Toronto and CBR Calgary (1010).

Whereas stations much farther apart may have much deeper nulls towards each other.

 

[DanStrassberg]

The 1010 situation is easier to explain. Canada has many Class A AMs that I call Class As in name only. That is, they do not provide protected nighttime skywave service. CFRB is one such; it may have been the first. Back around the time of NARBA (3/31/1941), CFRB was on the Class A channel that, after NARBA, became 860. CJBC was on whatever frequency became 1010. I think the US-Canada treaty that allowed a full-time AM on 1010 or its predecessor frequency in New York City had gone into effect before NARBA. But, regardless of the timing, the CBC, which back then was both a radio network AND the predecessor of today's combination of the CRTC and Industrie Canada, wanted the true Class A frequency for one of its Toronto AMs (that is, for CJBC) and it forced a frequency swap between CFRB and CJBC. CFRB was allowed to increase to 50 kW, albeit with a highly directional signal to protect both CBR (which did not yet exist, AFAIK) and WINS (which did). CJBC got the true Class A assignment on 860 and, with NARBA, became, with CBL 740, what must have been the first 50-kW/50-kW AM diplex in North America. Supposedly, if the CBC ever takes CJBC dark, the agreement that forced CFRB to 1010 gives CFRB first dibs on 860 in Toronto. Only in the last decade did the FCC allow (then) WTOP and KSTP to relax their nighttime protections toward each other. That ruling stated that the relaxation was not to be considered a precedent. But the Class B station in Detroit was a beneficiary. It was allowed a boot in night power to 10 kW using a nine-tower array protecting both DC and the Twin cities.

As for WTIC and KRLD, I can only guess at the history. The AM band was complicated before the advent of the rules that classified the channels and the classes of stations that were supposed to be assigned to them in something resembling the current configuration. I believe that WTIC shared time at night with WBAL and the two stations were among a not-insignificant number of station pairs that attempted to operate with synchronized carriers at night. Synchronous operation was a failure on the AM band in the US except in unusual circumstances. (KKOB's nighttime synchronous transmitter in Santa Fe is an example of an AM synch operation that works.) The owners of KRLD and WTIC or the Congressional delegations form Texas and Connecticut must have worked out a deal that allowed the two stations to use fairly relaxed protections to each other at night. Until last year, WTIC was one of very few Class As that did not switch to its night pattern until sunset at the co-channel class A to its west. The others are 1530 in Cincinnati and 1560 in New York City. 1110 in Omaha goes ND at Charlotte NC sunrise. Only in the last decade did the FCC allow (then) WTOP and KSTP to relax their nighttime protections toward each other. That ruling stated that the relaxation was not to be considered a precedent. But the Class B station in Detroit was a beneficiary. It was allowed a boost in night power to 10 kW using a nine-tower array protecting both DC and the Twin cities.

 

[ajaynejr]

Thanks.

 

[w9wi]

The 1010 situation is easier to explain. Canada has many Class A AMs that I call Class As in name only. That is, they do not provide protected nighttime skywave service. CFRB is one such; it may have been the first. Back around the time of NARBA (3/31/1941), CFRB was on the Class A channel that, after NARBA, became 860. CJBC was on whatever frequency became 1010. I think the US-Canada treaty that allowed a full-time AM on 1010 or its predecessor frequency in New York City had gone into effect before NARBA. But, regardless of the timing, the CBC, which back then was both a radio network AND the predecessor of today's combination of the CRTC and Industrie Canada, wanted the true Class A frequency for one of its Toronto AMs (that is, for CJBC) and it forced a frequency swap between CFRB and CJBC. CFRB was allowed to increase to 50 kW, albeit with a highly directional signal to protect both CBR (which did not yet exist, AFAIK) and WINS (which did). CJBC got the true Class A assignment on 860 and, with NARBA, became, with CBL 740, what must have been the first 50-kW/50-kW AM diplex in North America. Supposedly, if the CBC ever takes CJBC dark, the agreement that forced CFRB to 1010 gives CFRB first dibs on 860 in Toronto. Only in the last decade did the FCC allow (then) WTOP and KSTP to relax their nighttime protections toward each other. That ruling stated that the relaxation was not to be considered a precedent. But the Class B station in Detroit was a beneficiary. It was allowed a boot in night power to 10 kW using a nine-tower array protecting both DC and the Twin cities.

1010 had some strange things going on across NARBA. Will have to look at that tonight or tomorrow evening.

In a bit of a nutshell...

1932: CFRB was on 690, sharing time with CNRX. CJBC did not yet exist.
CNRT, the station that would become CBL, was on 1120.
CNRM Montreal was on 730, sharing time with CKAC and CHYC.

1933: CFRB had sole possession of 690.
CKAC Montreal had sole possession of 730.
CKLW Windsor owned the 840 frequency that would eventually become the CBC's.
CRCM (new calls for CNRM) moved to 910.

1935: CFRB still owned 690. (somewhat to the chagrin of WLW which had to go directional to avoid adjacent-channel interference from their 500kw rig)
CRCT (new calls for CNRT) took over 840 from CKLW. (I want to say CKLW was on 1030)
CRCM was still on 910.

Again, more on that later.

As for WTIC and KRLD, I can only guess at the history. The AM band was complicated before the advent of the rules that classified the channels and the classes of stations that were supposed to be assigned to them in something resembling the current configuration. I believe that WTIC shared time at night with WBAL and the two stations were among a not-insignificant number of station pairs that attempted to operate with synchronized carriers at night. Synchronous operation was a failure on the AM band in the US except in unusual circumstances. (KKOB's nighttime synchronous transmitter in Santa Fe is an example of an AM synch operation that works.) The owners of KRLD and WTIC or the Congressional delegations form Texas and Connecticut must have worked out a deal that allowed the two stations to use fairly relaxed protections to each other at night.

In 1932, KRLD and KTHS (Hot Springs, Arkansas; it would eventually become KAAY) were sharing time on 1040. WTIC and WBAL Baltimore were sharing 1060.

By 1935, KTHS and WTIC had swapped frequencies. KRLD and WTIC could operate simultaneously on 1040. (at least during the day and I presume at night through the use of directional antennas) KTHS and WBAL, likewise, could operate simultaneously on 1060. A 1933 listing shows WBAL with two frequencies -- 1060 and 760 -- I might presume WBAL operated on 1060 during the day and synchronized with WJZ Newark, NJ on 760 at night, assuming both stations carried the same network programs in prime time. That doesn't seem to have lasted for very long.

 

[w9wi]

The 1010 situation is easier to explain. Canada has many Class A AMs that I call Class As in name only. That is, they do not provide protected nighttime skywave service. CFRB is one such; it may have been the first. Back around the time of NARBA (3/31/1941), CFRB was on the Class A channel that, after NARBA, became 860. CJBC was on whatever frequency became 1010. I think the US-Canada treaty that allowed a full-time AM on 1010 or its predecessor frequency in New York City had gone into effect before NARBA. But, regardless of the timing, the CBC, which back then was both a radio network AND the predecessor of today's combination of the CRTC and Industrie Canada, wanted the true Class A frequency for one of its Toronto AMs (that is, for CJBC) and it forced a frequency swap between CFRB and CJBC. CFRB was allowed to increase to 50 kW, albeit with a highly directional signal to protect both CBR (which did not yet exist, AFAIK) and WINS (which did). CJBC got the true Class A assignment on 860 and, with NARBA, became, with CBL 740, what must have been the first 50-kW/50-kW AM diplex in North America. Supposedly, if the CBC ever takes CJBC dark, the agreement that forced CFRB to 1010 gives CFRB first dibs on 860 in Toronto. Only in the last decade did the FCC allow (then) WTOP and KSTP to relax their nighttime protections toward each other. That ruling stated that the relaxation was not to be considered a precedent. But the Class B station in Detroit was a beneficiary. It was allowed a boot in night power to 10 kW using a nine-tower array protecting both DC and the Twin cities.

OK. At the end of WW2, there were four North American stations authorized on 1010:
KLRA Little Rock (10,000/5,000 DA-N)
WINS New York (50,000/10,000 DA, already had a permit for 50,000/50,000) (would eventually, in the 1990s, buy out KLRA & return their license)
CBX Edmonton (permit only, not on the air yet. 50,000 watts. Transmitter at Lacombe, near Red Deer, would presumably serve both Edmonton and Calgary.)
CJBC Toronto (5,000 DA, permit for 50,000)

*During* the war, there were three stations authorized on 1010:
KLRA Little Rock (power unknown)
CBY Toronto (1,000 watts; for some reason would change calls to CJBC after the war)
CFCN Calgary (10,000 watts; would move to 1060 after the war, to allow CBX to occupy 1010)
KQW San Jose (1,000 watts; would move to 740 and become KCBS San Francisco after the war)

During the war, WINS was on 1000 sharing with KJR Seattle (would later swap frequencies with KOMO) and WCFL Chicago. (now WMVP)

Where these stations were pre-NARBA:
KLRA - 1390 5,000/1,000 (this frequency would become 1420)
WINS - 1180 1,000 watts limited time (presumably could remain on between NYC sunset and Albuquerque sunset; KOB Albuquerque was the "clear channel" station on 1180.)
CBX - didn't exist until after the war
CJBC - was CBY on 1420 with 100 watts. This was a "graveyard" (local channel) frequency, moved to 1450.
CBY - same station as CJBC
CFCN - 1030 10,000/10,000. The other nighttime station on this frequency was CKLW Windsor.
KQW - was on 1010 pre-NARBA as well but sharing with a mish-mash of stations:
CHML Hamilton, Ontario (100 watts)
CKCK Regina, Sask. (1,000 watts)
CKCO Ottawa (100 watts)
KGGF Coffeyville, Kans. (1,000 watts; shared time with WNAD)
WNAD University of Oklahoma, Norman (1,000 watts; shared time with KGGF)
WHN New York (5,000/1,000)
WNOX Knoxville (5,000/1,000)

 

[DanStrassberg]

Fascinating history, but I can absolutely tell you that, at some point, CJBC was on 1010 and CFRB was on 860. (I don't know the year, but it was likely shortly after the end of WWII and MAY have been DURING WWII, so I think it was within a year or two either way of 1945, when I was 10 years old.) I know this for a fact because my grandparents lived in Rochester NY and had a very elegant (made in Rochester) Stromberg-Carlson radio in their dining room. The radio was a huge table-top unit with lots of tubes in a wooden cabinet. I lived in New York City and when I visited my grandparents, I would sit in that room and listen to the Buffalo, Toronto, and Syracuse stations that came in--WGR, WSYR, CBL, CFRB, WBEN, CJBC, WKBW, and probably some others. I believe (from a White's Radio Log of the day) that CFRB 860 ran 10 kW (and I'm pretty sure that it was ND). CJBC was on 1010 with 5 kW, I think. I imagine that it was directional to protect WINS, but I'm not sure. I don't think that CHUM was yet on the air on 1050 and I believe that WINS was still running 10 kW-U (probably DA-1; WINS first increased D power to 50 kW and then, after several years, also increased its N power to 50 kW).

Also, a friend has since unearthed a copy of the agreement under which CJBC and CFRB swapped frequencies. CJBC moved to 860 with 50 kW-U ND and CFRB moved to 1010, also with 50 kW-U but was directional full-time. That agreement gave CFRB first dibs on 860 in Toronto should the CBC ever take CJBC dark. I have not personally seen this copy of the agreement, but everything my friend told me about it seems to agree with what I remember.

 

[w9wi]

Fascinating history, but I can absolutely tell you that, at some point, CJBC was on 1010 and CFRB was on 860. (I don't know the year, but it was likely shortly after the end of WWII and MAY have been DURING WWII, so I think it was within a year or two either way of 1945, when I was 10 years old.)

Yes, that's in that post. CBY (which would change calls to CJBC during or shortly after the war) moved from 1420 to 1010 at NARBA; while I didn't list CFRB in that post, it was on 860 after NARBA.

I believe (from a White's Radio Log of the day) that CFRB 860 ran 10 kW (and I'm pretty sure that it was ND). CJBC was on 1010 with 5 kW, I think. I imagine that it was directional to protect WINS, but I'm not sure. I don't think that CHUM was yet on the air on 1050 and I believe that WINS was still running 10 kW-U (probably DA-1; WINS first increased D power to 50 kW and then, after several years, also increased its N power to 50 kW).

I believe (also from White's) that you're right on all counts. CHUM was a post-war daytimer initially.

Also, a friend has since unearthed a copy of the agreement under which CJBC and CFRB swapped frequencies. CJBC moved to 860 with 50 kW-U ND and CFRB moved to 1010, also with 50 kW-U but was directional full-time. That agreement gave CFRB first dibs on 860 in Toronto should the CBC ever take CJBC dark. I have not personally seen this copy of the agreement, but everything my friend told me about it seems to agree with what I remember.

I've heard the same thing, about CFRB having first dibs on 860. If there were still any decent-coverage FM frequencies left in Toronto I'd bet they'd have a shot at it...

 

[w9wi]

Fascinating history, but I can absolutely tell you that, at some point, CJBC was on 1010 and CFRB was on 860. (I don't know the year, but it was likely shortly after the end of WWII and MAY have been DURING WWII, so I think it was within a year or two either way of 1945, when I was 10 years old.) I know this for a fact because my grandparents lived in Rochester NY and had a very elegant (made in Rochester) Stromberg-Carlson radio in their dining room. The radio was a huge table-top unit with lots of tubes in a wooden cabinet. I lived in New York City and when I visited my grandparents, I would sit in that room and listen to the Buffalo, Toronto, and Syracuse stations that came in--WGR, WSYR, CBL, CFRB, WBEN, CJBC, WKBW, and probably some others. I believe (from a White's Radio Log of the day) that CFRB 860 ran 10 kW (and I'm pretty sure that it was ND). CJBC was on 1010 with 5 kW, I think. I imagine that it was directional to protect WINS, but I'm not sure. I don't think that CHUM was yet on the air on 1050 and I believe that WINS was still running 10 kW-U (probably DA-1; WINS first increased D power to 50 kW and then, after several years, also increased its N power to 50 kW).

OK, here's the history of these as I've been able to figure it out:

CJBC -- seems to have come into existence between 1935 and 1937 as CRCY-1420, 100 watts. (1420 was a "local" channel, today 1450)
Shows up in a 1938 list on 960, but back to 1420 by 1940. Calls changed to CBY between 1937 and 1940.

Moved to 1010 during the war, increasing power to 1,000 watts.

By 1948, had changed calls to CJBC and increased power again to 5,000 watts with a permit for 50,000.

By 1950 had moved to 860 with 50,000 watts.

_________________________________________________
CBL -- dates back to at least 1931 as CNRT on 840.

By 1937 was CRCT with 5,000 watts and a permit for 50,000.

The 840 frequency was to become 860 after NARBA, but the station (by now CBL) moved to 740 instead, with 50,000 watts.

_________________________________________________
CFRB -- dates back to at least 1931 on 690 with 5,000 watts.

Increased power to 10,000 watts by 1932.

Should have stayed on 690 through NARBA but moved to 860 instead, taking over the channel CBL should have taken.

By 1948 had permit for 50,000 watts on 860.

By 1950 had moved to 1010 with 50,000 watts.

_________________________________________________
Two Montreal stations have to be considered as well.

CBF, formerly known as CNRM and CRCM, dates back to at least 1931. 730 with 5,000 watts, sharing time with CKAC and CHYC.

Moved to 910 by 1935, with 5,000 watts and sharing with nobody.

Power increased to 50,000 watts by 1937.

The frequency should have become 940 after NARBA, but the station moved to 690 instead. That frequency had been dropped by CFRB.

_________________________________________________
CBM appears to date back to 1937, when it launched on 1050 as CRCM with 5,000 watts. (1050 would have become 1070 after NARBA)

Moved to 960 in 1940.

This frequency should have become 990 after NARBA, but the station moved to 940 instead. (the post-NARBA frequency that should have gone to CBF)

Power was still 5,000 watts by 1950, don't know when it increased to 50,000.

_________________________________________________
I strongly suspect the reason for CFRB's move from 690 to 860 was adjacent-channel interference from WLW, especially in light of WLW's 500,000-watt experiment. Moving the 690 frequency from Toronto to Montreal would considerably reduce this problem.

 

[davideduardo]

I believe (from a White's Radio Log of the day) ....

I believe (also from White's) ...

In case you have not discovered them---

Whites... http://www.davidgleason.com/Whites_Master_Page.htm
Radex... http://www.davidgleason.com/Radex_Master_Page.htm
Radio Annual... http://www.davidgleason.com/Radio_Annual_Master_Page.htm
Broadcasting Yearbook... http://www.davidgleason.com/Broadcasting_Yearbook_Summary_Page.htm
Broadcasting Magazine... http://www.davidgleason.com/Broadcasting Individual Issues Guide.htm (complete 1938-1949)

 

[w9wi]

In case you have not discovered them---

Whites... http://www.davidgleason.com/Whites_Master_Page.htm
Radex... http://www.davidgleason.com/Radex_Master_Page.htm
Radio Annual... http://www.davidgleason.com/Radio_Annual_Master_Page.htm
Broadcasting Yearbook... http://www.davidgleason.com/Broadcasting_Yearbook_Summary_Page.htm
Broadcasting Magazine... http://www.davidgleason.com/Broadcasting Individual Issues Guide.htm (complete 1938-1949)

Yep, I'm quite aware of them and they are greatly appreciated!

Y'know, been meaning to mention.. I do have a 1966 Yearbook. There are a few pages missing from the front. ISTR that year is in the list of those you don't have?

 

[DanStrassberg]

CBM appears to date back to 1937, when it launched on 1050 as CRCM with 5,000 watts. (1050 would have become 1070 after NARBA)
Moved to 960 in 1940.
This frequency should have become 990 after NARBA, but the station moved to 940 instead. (the post-NARBA frequency that should have gone to CBF)
Power was still 5,000 watts by 1950, don't know when it increased to 50,000.

In 1952, I started in college in Troy NY, where several of the 50 kW Montreal stations were audible day and night. CBM was running 50 kW on 940 by that time and I had the impression that it had been doing so for more than a couple of years. Also, I believe that either CKVL or GKGM was on 980 in Montreal/Verdun. 980 from the Montreal area was, of course, not audible in Troy because of the local WTRY (now WOFX). More recently, when CBF 690 went dark, CKVL, which had moved to 850, moved again, this time, to 690 and took the CINF calls. CINF is now also dark and I have heard no news about any possible resurrection of 690 in Montreal. CKGM moved to 990 and may now have different calls (CHTX?). When CBM went dark, CFCF 600 (allegedly North America's first radio station), took over 940 from CBM, using the calls CINW. CINW is now also dark and I have heard no news about any possible resurrection of 940 in Montreal.

 

[davideduardo]

Y'know, been meaning to mention.. I do have a 1966 Yearbook. There are a few pages missing from the front. ISTR that year is in the list of those you don't have?

Yes, that is one that I do not have... despite looking for the critter for the last decade.

BTW, I just rescanned 55 of the Radex mags... will be up in a day or so.

Whites will also be redone... availble soon.

 

[cyberdad]

Yes, that is one that I do not have... despite looking for the critter for the last decade.

[/quote]

Unfortunate that I didn't know that or know about your site three years ago. I had the '66 yearbook and would have been more than happy to donate it to your library, but lost it during flooding in August, 2007. I had the complete set from my years of Junior High and High School....'62-'66. Along with most issues of the magazine from that period. Lost 'em all.

 

[davideduardo]

Unfortunate that I didn't know that or know about your site three years ago. I had the '66 yearbook and would have been more than happy to donate it to your library, but lost it during flooding in August, 2007. I had the complete set from my years of Junior High and High School....'62-'66. Along with most issues of the magazine from that period. Lost 'em all.

Thanks for the thought. Fortunately, the only one from the 50's or 60's I am missing is '66, although my '59 is in such terrible shape I would love a better one (the paper aged far worse than I have...).

I think I now have all the magazines from that decade, but it will be a while before I can scan them all. I should be complete from 1938 to 1989 at that point... about 2800 of them! You don't want to see my garage (we don't have basements or attics here).