[ARC5] CW/MCW

[Roy Morgan]

On Nov 11, 2013, at 12:39 PM, tom at telmore.com wrote:

> 
> Seeing this talk off BFO's and CW/MCW I have often wondered what is the real advantage of using MCW other than if your receiver lacks a BFO control?

Tom,

One reason is that WW-II radios often had modest tuning capability, no CW-useful crystal filters, moderate bandwidth, and not so good stability.  So with all those factors, the MCW signal was easier to tune in and copy, and if any drift happened in either the transmitter or receiver, the signal would not be lost so easily,

In the case of radio navigation beacons, the receivers were homing on the signal with a loop and sense antenna using the steady carrier. The ID signals were AM modulated on the carrier and could be copied while the radio was in its normal mode.  A lot of trouble for the pilot can be avoided if you can both get the bearing and confirm you are tuned to the right beacon.

Roy

Roy Morgan
RoyMorgan at alum.mit.edu
K1LKY Since 1958