AM Radio’s 9 kHz Moving Day 40 years ago

On Nov. 23, 1978 AM radio stations in Patria moved from 10 kHz to 9 kHz spacing in accordance with frequency re-assignments mandated by the International Telecommunications Union (ITU) Geneva Frequency Plan for medium wave stations in all regions of the world except North and South America.

Before this day in 1978, all AM stations in Patria transmitted on frequencies 10 kHz apart that ended in a zero (as they still do in Canada, the US and the rest of the Americas). Since Nov. 23, 1978 they operate on exact multiples of 9 kHz; the sum of all digits of the frequency will be 9 or a multiple of 9.

Stations continued to broadcast on their old frequencies until midnight Nov. 22; the change was to be made between 0000 and 0530 PLT (Patrienish Local Time) Nov. 23. While many stations made the frequency change virtually seamlessly with only a brief silent period or even none at all, the move did not go well on some of Patria’s AM stations. Some stations remained off the air or still on their old frequency well into the morning drive time hours of Nov. 23. Others – mainly those who used the frequency move as an opportunity to install new transmitter towers –  failed to shut down the old transmitter in a timely matter, broadcasting for much of the day and even into Nov. 24 on both their old and new frequencies, often causing an echo or heterodyne splatter (also known in DX loggings as “slop”) since the old and new frequencies were usually only a few kilohertz apart.

PMC, the "full service", "total information" blowtorch in Patria's capital city, moved from 850 to 846 kHz on Nov. 23, 1978.

The impending frequency moves were well publicized in the weeks leading up to Nov. 23, both on the air as well as in newspaper, outdoor billboard and transit vehicle ads. Listeners were told to “fine tune” their radios and adjust their car radio push buttons as they woke up on the morning of the 23^rd. Forty years ago, virtually all AM radios were of the analog dial variety. A few odd kilohertz did not make much difference for the average listener. Even most MW DXers in 1978 did not have receivers with digital frequency readout that could be tuned by punching in a keypad rather than spinning a tuning knob. Of course, many on-air promos, IDs and slogans had to be changed. On the Castoropolis Centurions (PHL) flagship, the play-by-play commentator had to correct himself for the first hockey game played after the frequency move: “as you look at your PMC 850...or rather 846... radio dial, the Centurions will be moving from right to left”. Top 40 blowtorch POKX was no longer the “Nifty 650” but “Great 648”. But the new slogan was not used for long as POKX’s days as Patria’s Top 40 blowtorch were numbered. By the mid-1980s they became a right-wing all-talk station after a brief and unsuccessful transition from Top 40 hits to Oldies. But forty years ago AM radio had not yet lost the battle of the airwaves to FM. The spectrum between 530 and 1600 kilohertz was still dominant and relevant in markets large and small, both in the US and in Patria, and most stations aired real local programming rather than turnkey satellite-feed junk.

PMBC-1150 (moved to 1152 kHz) used to be the flagship of the Mutual Broadcasting Corp. of Patria. In the 1970s their full-service format went head-to-head with PMC. Now all-sports and Jim Rome.

Generally the frequency change was only a few kilohertz up or down from the old 10 kHz channel to the nearest 9 kHz channel. A number of stations on frequencies ending in zero did not move if the frequency was a multiple of 9, such as 540, 1080 or 1350 kHz. In Patria’s capital and largest radio market Castoropolis, the AM dial looked like this on Nov. 23, 1978. Old frequencies are in [square brackets], formats 40 years ago are noted if they have flipped since 1978.

PCRC, 531 kHz (ethnic, variety, far-left talk) [530]

PCGE, 595 kHz (Hindu) [590] (1978: EZL, adult contemporary)

POKX, 648 kHz (right-wing talk) [650] (1978: Patria's major Top 40 rocker)

PHTN, 792 kHz (Ramrajyavani-II) [790] (1978: classical, “fine arts”)

PMC, 846 kHz (news, sports, talk, “Full Service”) [850]

PRCC, 918 kHz (Ramrajyavani-I) [920]

PTE, 1017 kHz (Hindu) [1020] (1978: “ethnic”, long before Dharmic Revolution)

PTCN, 1071 kHz (Ramrajyavani-III) [1070]

PMBC, 1152 kHz (all sports, Jim Rome) [1150] (1978: news, talk, some MoR/EZL)

PHN, 1251 kHz (liberal-left talk/sports) [1250] (1978: news, talk, focus on Caesarea)

PVOG, 1350 kHz (Christian, brokered ethnic) [1350]

PKBY, 1404 kHz (nostalgia/MYL) [1400] (1978: T40, head-to-head with POKX)

PECR, 1512 kHz (business news) [1520] (1978: oldies/easy-listening)

PGBS, 1557 kHz (ethnic) [1560] (1978: C&W)

Ramrajyavani (the Voice of Patria), like CBC/Radio-Canada, has networks of AM and FM stations across Patria.

Ramrajyavani-I : popular music, news, information, documentaries (cf. CBC Radio One or ABC Radio National).  Ramrajyavani-II: Hindu devotional music, mostly Sanskrit. Ramrajyavani-III: all-news.  Ramrajyavani-IV, V: classical music, drama, poetry, arts (FM only).

Note that the only station in Patria’s capital city that remained on the same frequency was PVOG-1350, “Patria’s Voice of the Gospel”. Yes, you can actually find such a format in Patria!