Kilocycles

[radiojay1]

I was reading on 650 WSM's website that their low 650 kilocycle frequency gives them an advantage in coverage. Are kilocycles the same as kilohertz and does having a lower AM frequency give you an advantage in groundwave or skywave coverage?

 

[rfry]

I was reading on 650 WSM's website that their low 650 kilocycle frequency gives them an advantage in coverage. Are kilocycles the same as kilohertz?

No. The term "kilocycles" literally means one thousand cycles. But that doesn't define a frequency, because it does not state the time interval that those 1,000 cycles occupied (although it could be argued that this is understood to be one second).

The term "Hertz" means cycles per second, by definition. So 650 kHz means that 650,000 cycles of the r-f carrier occur in a one second time interval.

and does having a lower AM frequency give you an advantage in groundwave or skywave coverage?

Other things equal, lower radio frequencies have less groundwave propagation loss than higher ones. But a lower MW frequency doesn't much affect the nighttime skywave.
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[Tom Wells]

I am 45, but became radio-aware at 2 years old, was sure I'd go into the industy, and watched it all slump until just about the point I was ready to take the 1st class phone, it was eliminated. I learned from OLD teachers at the oldest school (see below) 1874-1987 R.I.P.
I still have to make sure I say hz because I sure do think in cycles. All the old guys said cycles, so that web entry was by someone
who just didn't notice at all when they typed it.

The vice president of the school, Art Hershman, taught the ECD3
(Electron Control Devices) class, among others, and was adamant "What Are the UNITS?" , he would thunder. He would give credit in answers which had gone astray numerically but had the right power of ten, while giving no credit to any answer that did not include proper reference to the units.

My favorite problem he posed that we had to calculate the speed of light, expressed in terms of
furlongs per fortnight.

Full agreement with previous post. The groundwave advantage for lower frequencies is large, this is why LW was used effectively in Europe as a broadcast band, coverering 2 to 3 times the radius in daytime coverage for our 50kw non-directional ams @ 540-1700.
At night, it's a toss-up, but seems to favor higher frequencies, probably because skip angle and distance to 1st skip always favors the higher
frequency, well, almost. But since the higher AM dial is so full locally, the old (semi) clears on AM can often go farther due to far fewer
stations on that frequency at all.

 

[semoochie]

Most words used in electronics are derived from someone's name. It was usually the person who spent his lifetime studying that particular facet or as my old electronics teacher used to say, "He stayed up all night, trying to figure it out!". The only one that comes to mind is Simon Ohm but Hertz was such a man(He spent his life studying cyclic occurances)and unlike Ohm and others, didn't get the same kind of credit until about 30 years ago when the term "cycle" was replaced by "hertz". Prior to that, most radios were labeled "kc" (and "mc" if applicable).

 

[rfry]

... the term "cycle" was replaced by "hertz".

Not strictly so, because the term "hertz" means cycles per second, not "cycle."

The form of abbreviation for many electronic units of measure often is incorrectly written, especially with regard to capitalization. For example, the correct form of the abbreviation for megahertz is MHz, but other forms of that often are seen in informal writing, such as mHz (means millihertz), mhz (means nothing), MHZ (means nothing).

Here is a background link for standard "SI" units... http://physics.nist.gov/cuu/Units/introduction.html

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[K6JHU]

Somebody once pointed out that we should have honored another great electroincs genius when changing the unit of frequency. Instead of Hertz, we should have honored Charles Proteus Steinmetz. That way we could have abbreviated the unit of frequency as ..... wait for it..... CPS