[MRCA] code wheel

Mike Morrow kk5f at earthlink.net
Thu Apr 23 02:56:48 EDT 2015


> What about that dot to dash ratio. Looks like about 5:1?  A ratio
> of 3:1 would be quite a bit of "swing"...

A dash:dot ratio of 3:1 would be NO swing at all.  That is the exact definition of the proper lenghth of dash compared to dot for zero weighting.

WRT the actual transmitted dash:dot ratio, one would probably need to examine the dynamics of the remainder of the keying system...like the arm and switch activated by the toothed cam...to know the effective weighting profuced by the wheel.

I always like to examine the Morse keying wheels found in various maritime and aircraft emergency sets that send SOS.

Most hams...even older ones...do not know that SOS should be sent as one character...not three  ( ---...---, not --- ... --- ).  That's the way tge BC-778-* and T-74*/CRT-3 Gibson Girl transmitters send SOS, but not the USAF's KY-65/ARA-26 emergency keyer for the AN/ARC-21, -65, and -58 sends SOS.  That unit's code wheel for SOS sends the incorrect --

- ... --- version.  

Mike / KK5F


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