semoochie said:
I have another question about a foreign land to which I have never been: When I looked at the situation about 30 years ago, I noticed that there were 30 AMs licensed to Mexico City with no FMs at all! The stations at the middle and top of the dial were 30khz apart but at the bottom were only 20khz apart. They usually had 2 high power stations with a 1kw station squeezed between. This must have been and probably still is a technical nightmare! Any thoughts on this?
Well, most FMs in Mexico City, as in Latin America, started as studio transmitter links. In 1970, I was offered the programming of 5 FMs in Mexico City when they were about to move to 180,000 watts each from the Torre Latinoamericana, the highest building in the valley. Even before that, stations like XHM, "Un Oasis en FM" and XELA (Buena Música en México" had separate FM formats and a couple had started to do OK.
In 1975, 30 years ago, the allocation was the same on AM as today. 560, 590, 620, 660, 690, 710, 730, 760, 790, 830, 860, 900, 940, 970, 1000, 1040, 1060, 1110, 1150, 1180, 1220, 1260, 1290, 1320, 1350, 1380, 1410, 1440, 1470, 1500, 1530, 1560, 1590. No change, except nearly all are much higher power today.
For example, 690 is 100kw, 710 is now 10 kw, and 730 is 100 kw. 760 is 75 kw, 790 is 50 kw, 830 is 50, 860 is 50, 900 is 250 kw, 940 is 50, as are 970, 1000, 1030, 1060, 1110 and 1150. 1220 is 100, 1260 is 50 as is 1290 and 1320. 1350 is reported 10 kw, 1380 is 50, 1410 is 20.
I owned HCRM1 and HCSP1 in the same market, Quito, Ecuador, in the 60's. One was 570, and the other 590. No problems at all, not even near the transmitter sites.