[CQ-Contest] Fw: Skimmer as technology

Doug Smith w9wi at w9wi.com
Sun Feb 10 13:01:09 EST 2008


On Thu, 2008-02-07 at 21:07 -0600, John Brosnahan -- W0UN wrote:
> A lot more google hits for "rectified" than "raw" alternating current.
> 
> And this list of CW abbreviations makes one believe that
> it must be Rectified Alternating Current.

I'm way too young to have seen it firsthand but from my reading, I
always thought it meant "raw" AC.

What's the point of rectifying it if you're not using a filter?  Can't
you just put the raw AC on the plates?  Nothing nasty is going to happen
on the negative half-cycle, the tube will just sit there & do nothing.
(just like it would with a rectifier, during the negative half-cycle
while the rectifier is cutting off the current)

Indeed, June 1926 QST shows several circuits that do just that - apply
unrectified 110v AC to the plate of an oscillator tube.  In this case
they didn't mean for the signal to be transmitted - it's a test
oscillator for checking receivers - but the circuit does apparently
work.

In that article, and in another article about a transmitter that had a
filter but apparently not an adequate one, the phrase "raw A.C." is
used.  

In another article, the phrase "rectified A.C." is used, but it's
immediately followed by a sentence describing the filter following the
rectifier, and stating that the station using that power supply receives
reports of "nearly pure D.C. signals".  

Nowhere in June 1926 QST does the abbreviation "RAC" appear.


-- 
Doug Smith W9WI
Pleasant View, TN  EM66



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