Do you believe everything that you read?

Sometimes the written instructions you receive just are wrong. On April 10, 2019 there was an article at Computerworld in Shark Tank titled Don’t RTFM, and subtitled Do you believe everything you read? RTFM is the overused acronym for Read That Friendly Manual.

It told a story about a radio transmitter used by the army. The storyteller, who maintained electronics, had been in a unit where that equipment first was deployed. He and others were trained by the manufacturer, or by those who they had directly trained. Their units had only minor problems with the transmitter. But other units had many failures of the large, expensive final amplifier tube similar to one shown above.

Eventually he and a senior operator were assigned to visit one of the other units. That senior operator watched what the others were doing, and was horrified. Before shutting off power to the transmitter they were turning the gain control knob for the final amplifier fully clockwise (CW) to maximum power. Instead they should have been turning that knob fully counterclockwise (CCW) to minimum power, as shown above.  

They said we just were following orders. We did exactly what the manual told us to do! They didn’t think about whether that instruction made any sense. He corrected the manual to say counterclockwise, and informed  all other units to do the same.

What had gone wrong? Presumably whoever began writing the manual meant to use the abbreviation CCW but accidentally left off one C – a simple typographic error. Then during editing the words got spelled out but incorrectly.

I remember once seeing a case about a tall retaining wall in a book on construction failures. The drawing had specified 1-1/4” diameter steel reinforcing rods. When the drawing was copied the ‘1’ got so light it was illegible, and much thinner 1/4” rods were used instead!

An image of a vacuum tube came from Wikimedia Commons.