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May 25, 2004


Digital art 250 by 250 pixels. Neat. Now can someone tell me where the expression "five by five" comes from? Not that it sounds the same coming from me as from Faith. Oh wait, here it is. But that leaves me wondering what the technical origin is from the radio communication people.

Posted by Ghost of a flea at May 25, 2004 08:29 AM

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"Five by five" is easily explained. It comes from US military radio operators, who used the phrase to tell the transmitting person/aircraft/station how well they were being heard. There was a five point scale in two categories, signal strength and clarity of transmission. A strong, clear signal was coming in "five by five" whereas lesser signals would be indicated by lesser numbers (i.e. "one by one").

Commonwealth troops used the much simpler "I hear you loud and clear", but most of us have fallen prey to the "five by five" lingo now.

Posted by: Chris Taylor at May 25, 2004 12:05 PM

We did/do not use "loud and clear" during a radio check as the response "Roger, Over" indicated that. If there was a problem then one would send "weak", "distorted", or other description of the received signal.
Having said that, I shall consult my Comms expert tomorrow for a proper answer.


Posted by: J.M. Heinrichs at May 25, 2004 09:43 PM

J.M., it was way before your time. Unless you were around for the Great War or the inter-war period, then you will not have heard Commonwealth troops utter "I hear you loud and clear" as part of standard radio discipline. It was thoroughly out of fashion by the end of the Second World War.

Posted by: Chris Taylor at May 25, 2004 10:22 PM

Oh I forgot to add, that "Thunder in the Morning Calm: The Royal Canadian Navy in Korea, 1950-1955", (by one Edward C. Meyers) notes the term "loud and clear" being in use as late as the Korean War -- which is almost too difficult to believe, because military radio discipline across all services had become much more formalized and concerned with opsec in WW2.

Posted by: Chris Taylor at May 25, 2004 11:46 PM

Actually, during my time as a shortwave radio geek, I learned about five by five. Its actually a 5 element scale with ratings from 1 to 5 on each. Its usually called by the acronym SINPO (Signal strength, Interference, Noise, Propagation disturbance, Overall merit). If you heard it 5 by 5, that would mean you heard it with no interference and excellent signal strength.

Posted by: Dr_Funk at May 25, 2004 11:47 PM

Awesome detail, Funk. That's a hell of a lot more than they teach you in ground school. =)

Posted by: Chris Taylor at May 26, 2004 12:23 AM

We use "Lima Charlie" (LC) for "Loud and Clear."

Or "Lima Alpha" for "Loud and Annoying."

Posted by: Ian at May 26, 2004 08:24 AM

I love comments! Must now add Lima Alpha to my vocabulary.

Posted by: Flea at May 26, 2004 11:16 AM

Well I checked with the Subject Matter Expert (aka SME) and he allows that I am correct. Or rather, that was then, this is now. Some variation of "5 x 5" or "loud and clear" would have been accepted until the mid/late 60's when the Army changed from 'old' Brit radios to 'new' US radios: the former required tuning etc, while the latter used preset frequencies and such. So either a generic "Roger, Over", or a specific "Weak and distorted" is the rule today. And no CB junk allowed.


Posted by: J.M. Heinrichs, Capt at May 26, 2004 03:03 PM