Directional ex-Class IA AMs

Mon Nov 23 13:33:38 EST 2009

On Nov 23, 2009, at 9:27 AM, Dan.Strassberg wrote:

> I absolutely can't agree with the north-south orientation of the two
> towers. It HAD to be roughly east-west. Maybe you were confused by the
> orientation of the shore-line at the site. At that spot, the
> shore-line very likely runs south to north. The objective was to
> reduce radiation over Long Island Sound and increase it over New York
> City. As you pointed out, a two-tower setup could do that only if the
> towers were on a more-or-less east-west line. One corroboating fact is
> that, when 750-kW superpower was being considered for roughly half of
> the then-IA AMs (maybe 1960s), 660 was held back from further
> disposition; that is, no Class IIA assignment was made on 660 at that
> time. 770 already had KOB, which was a special case and was made a
> IIA. 880 got KRVN. 660 _ultimately_ got KTNN, a IIA-like station, but
> that was after the superpower idea had died. KTNN began life either as
> a Class II (no A suffix) or went straight to Class B. I don't think I
> can list all of the IA channels to which no IIAs were assigned, but
> here's a stab at the list: 640, 650, 660, 700, 720 (I think) 750, 760,
> 820, 830, 840 (I think), 870, 1040, 1160, 1200. (Hmmm... that's 14; I
> thought there were only 13.) I don't think the stations in NV on 720
> or 840, though IIA-like, ever were IIAs. Note also that KTWO on 1030
> WAS a IIA, which always seemed odd to me, because you'd think 1030
> would have been held back because WBZ was already directional. Also
> note that being near the geographical center of the 48 contiguous
> states didn't preserve a station's candidacy for superpower: KPNW was
> assigned to 1120, thus limiting KMOX to 50 kW.

The United States started out with forty ... yes FORTY ...  
frequencies on which stations of the Class I-A type (de-facto) were  
allocated, with five such stations per geographic "region", over the  
eight "regions".

Yet, we wound up with only 25 Class I-As (in-fact) after NARBA.

U.S. Class I-A frequencies were: 640, 650, 660, 670, 680 (*), 700,  
720, 750, 760, 770, 780, 810 (*), 820, 830, 840, 850 (*), 870, 880,  
890, 1000 (*), 1020, 1030, 1040, 1100, 1110 (*), 1120, 1160, 1180,  
1200 and 1210.

680 (San Francisco) was broken-down for Raleigh, and later Boston,  
but it was a Class I-A in the beginning.

810 (Oakland) was was broken-down for Schenectady, but it was a Class  
I-A in the beginning. General Electric's flagship station, WGY wound  
up with ND-U, whereas KGO wound up with DA-1.

850 (Denver) was broken down for <somewhere, Florida, I think>, and  
later Boston, but it was a Class I-A in the beginning.

1000 (Seattle) was broken-down for Chicago, but it was a Class I-A in  
the beginning.

1110 (Charlotte) was broken-down for Omaha, but it was a Class I-A in  
the beginning. CBS got 100 percent use of 780, by KFAB vacating that  
frequency, forever, in return for KFAB moving to 1110 and KFAB and  
WBT both directionalizing, but WBT's directional was not completed  
under CBS' ownership.

Of the 25 Class I-As, after the initial break-downs mentioned, above,  
the following were in the initial Class II-A List, and were available  
for specific states within the under-served West: 670, 720, 780, 880,  
890, 1020, 1030, 1100, 1120, 1180 and 1210. The revised Class II-A  
List included 770.

720 was available for either Idaho or Nevada, but went to Nevada (Las  

1120 was available for either California or Oregon, but went to  
Oregon (Eugene).

After revision, 770 went to New Mexico (Albuquerque), as a final  
solution to the infamous "KOB Problem".

Class I-As which have operated with directional antennas include:  
660, 870, 1030 and 1100. Presently, only 870 and 1030 operate  

>> WABC, WMAQ, and WGN are three stations that have roughly half-wave
>> towers with shorter aux towers on the property that I understand
>> were used in the early days to directionalize the signals a bit. All
>> are "ND" today, and the aux towers are available for standby use but
>> mostly they just support STL and other aux antennas.

All the network O&O Class I-As had auxiliaries. A few of their Class  
I-Bs, too.

WLS' auxiliary was built in the 1980s. It is 199' tall and is built  
for 50 kW, unlike some auxiliaries, such as KFIs, which is built for  
only 25 kW.

If WLS' auxiliary was built after "Rio", then it would have been  
ratcheted, as were the WFAN/WCBS and WWL auxiliaries, on account of  
interference to new Class As in Central and South America. Also Cuba.

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