Who is the official national time keeper?

Peter Ndirangu has several questions about broadcasting stations. First, he notes that there are over 50 radio stations in the country all using the FM frequency band. He wonders what will happen if and when if the Communications Commission of Kenya (CCK) exhausts the FM band. “Will they revert to the old and noisy MW/SW?”

No. That would be driving in reverse gear! The better step would be top go digital. This is already happening in television broadcasts. The advantage of digital broadcasts is that many radio stations can transmit in the same frequency without interference. In addition, sound quality is better than normal FM broadcast.

Peter’s second question is about the time announcement by different radio and TV stations: “I wonder which radio/ TV station is telling time correctly. All the radio/TV station will claim it is 7pm news. Yet one is 5minutes behind, another 3minutes ahead… but they [all] claim it is 7pm.

“Suppose these stations want to re-set their clocks so that there is uniformity in telling time, where can they get assistance? Who owns a watch that tells time correctly?”

The national broadcaster is the official time keeper in many countries. In others, it is the national telecommunications corporation. In Kenya, that would be the either the Kenya Broadcasting Corporation or Telkom Kenya.

Indeed, in the old days of Kenya Posts & Telecommunications Corporation, one would dial a short code number (I think it was 0979) on any telephone and get a time announcement, like “On the third stroke, the time will be…”

Since Telkom Kenya has been privatised, I consider KBC to be our official time keeper. Thus anyone with a time different from that on KBC is wrong. Even if KBC’s clock is off, it still remains the correct official time.

Peter’s third question is a little perplexing. He say’s: “During this year Jamuhuri Day, we tuned the same TV station with my neighbour. The moment a speaker finished pronouncing certain word in my TV set the same word was heard in my neighbour’s TV 7 seconds later. My TV set is 7sec ahead in receiving news. Why this?”

I have never observed this phenomenon where there is a delay between two TV sets tuned to the same station. But on many occasions I have noticed delays when two stations (say, NTV and KBC) are transmitting the same event live. This is noticeable when I switch from one channel to the next.

Some people speculate that these delays arise from the journey of the broadcast signal from Earth to some satellite in the sky and back. This however, is not true.

Broadcast signals travel at the speed of light – about 300,000km per second. Communications satellites are about 35,000km up. Therefore, the journey would take only a fraction of a second (0.2s) to go up and down! And in any case, local live broadcasts don’t have to be bounced off satellites.

The delays are intentionally introduced to allow editors to remove any unwanted content in the transmission. Since different stations may use different delay times, say 7s on one and 10s, the latter will be 3s behind the former.