Re: "Layman" understands conductivity
> That Houston had only one 50 kW AM used to perplex me as a
> kid in the 50s and early 60s as I dx’d on my Transoceanic
> and continued when I moved away and could almost never pick
> up Houston stations.
>
> Houston only became the largest city in the state in the
> 1930 Census, surpassing San Antonio, and businesses with the
> financial well-being to put stations on the air and keep
> them on the air seem to have come to radio later in Houston
> than elsewhere in the state.
>
> Look at the oldest stations: Dallas (WRR, first station in
> Texas, 1921), Bryan-College Station, Austin, Fort Worth,
> Waco and San Antonio all had stations on the air by
> September, 1922, that are still on the air.
>
> But KPRC (Kotton Port, Rail Center), the oldest station
> still on the air in Houston, didn’t start until May 9, 1925,
> altho it might have been on the air much earlier but for an
> untimely death.
>
> By 1930, of the 15 licenses authorized in Houston only 4
> were still on the air and none of the ones prior to KPRC.
> Two of the four had just signed on in 1930. By ca. 1932-33,
> the city had only 3 stations - KPRC, KTRH, KXYZ - and it
> stayed that way until KTHT signed on in 1944.
>
> Then when Dave Morris put KNUZ on the air in 1948, he
> concluded he only needed 250 watts at 1230 kc (to be
> historically accurate) to cover the city.
>
> It seems to me Houston businessmen just didn’t take to the
> medium with as much
> enthusiasm as elsewhere and underestimated the growth of the
> medium and the city and therefore may not have seen the need
> to seek higher power authorizations.
>
> Also, I’m only a layman and didn’t understand all of your
> technical discussion, but wouldn’t the superior conductivity
> (closer to the coast?) also have been a reason Houston
> businessmen might not have felt the need to seek higher
> operating power?
>
Your observations probably hit very close to the truth. Houston's "late bloom" probably had much to do with the lack of 50 kw's here. Heck, even places like Waterloo, Iowa and Fort Wayne, Indianna (HUGE metros) wound up with the 50 kW Class I operations.........and probably because someone saw the future, staked a claim to the frequency, and fought to keep it.
Back in the 20's and 30's (especially after the Roosevelt administration took over in 1933), there was a lot of jockeying around on frequencies and power. Prior to FDR, there was federal oversight of the frequencies but they were treated more as a "property rights" thing. Only after FDR did licensees become "public trustees." Of the original 100 AM channels, 25 were set aside as U.S. Class 1-A stations (50,000 watts day and night, non-directional) with only one dominant station on the frequency.
Others were classified as class I-B stations with TWO dominant stations, each ATLEAST 10,000 watts but up to 50,000 watts day and night, BUT with a directional antenna system at night to protect the other Class I-B in the U.S. These two stations were generally located on opposite ends of the country from each other and used simple two or three tower arrays to protect each other at night. (I know of only one 1-B that never upgraded from 10,000 watts to 50,000 watts (KNZR, Bakersfield, CA on 1560 kHz).
There were, I think, 15 channels set aside for Canada and Mexico to have 1-A clear channels (740kHz, for instance is actually a Canadian Clear, so is 1010 kHz). U.S. stations could operate on those channels as long as the Canadians were protected. Many U.S. allocations became daytimers on these frequencies and most did not operate with 50 kW although it was allowed.
Most of the rest of the channels were classified Class III or "regional" channels and were limited to not more than 5 kw day and 5 kw night (610 kHz, 790 kHz, 950 kHz, 1320 kHz, 1430 kHz and 1480 kHz, all Houston allocations, fell into this catagory). This 5kw limit rule was abolished in 1993 giving all old Class III stations the right to go to 50 kw.......ASSUMING THEY COULD PROTECT OTHER STATIONS ALREADY ON THE AIR. Unfortunately, (which is the case with pretty much all Houston's old Class III's except KXYZ) allocation protection requirements to co channel and adjacent channel stations act to prohibit most Class III's making this improvement. It's a shame because most metro's have long outgrown the coverage areas of the large number Class III's that populate them.
Incidentally, you mentioned Dave Morris only "needing" 250 watts to cover Houston on 1230 kHz. That's not exactly right. In the 1933-35 shuffle of frequencies and power, six frequencies were set aside as Class IV or "local" channels.........1230 kHz, 1240 kHz, 1340 kHz, 1400 kHz, 1450 kHz, and 1490 kHz. These six frequencies were all to be NON-Directional (both day and night) and were originally granted only 100 watts of operating power. They were intended to serve only small communities like Huntsville, Lufkin, Nacogdoches, etc.
In 1945, they were allowed to go to 250 watts fulltime (David Morris took the 250 watts because that was all he could get at the time). In 1963, the Class IV's (at least those not near the Canadian border where the Canooks pitched a fit) were allowed to increase daytime power to 1 kw but were restricted to 250 watts at night. Finally, in the late 1980's, they were allowed to increase night power to 1 kw as well.
The problem with the old Class IV's is that there are so many of them and they all have to just accept interference generated by the hundreds of others on the frequency. Under Section 73.37(e)(ii) of the FCC's rules, they were also allocated as though they operated at 250 watts even though they had almost all gone to 1 kw! What a horrible mess.
Your are though, right about the conductivity along the coastline of Texas having much to do with the lack of 50's here. Other than KTRH, the only other 50 kW operations right along the Texas coast (again, KGOL is way up in the crappy conductivity and has a signal much more in line with a 5 kw than a 50) are KCTA on 1030 kHz (U.S. 1-A clear) in Corpus Christi and KGBT on 1530 kHz (U.S. 1-B clear) in Harlingen. The incredible conductivity along the coast is the chief reason for this (KGBT, for instance has MORE than 1 mV/m of signal in Freeport.......hundreds of miles from Harlingen).
Still seems odd that Houston got so shortchanged in the original dealing.