Re: cw sidebands


From: Mont Pierce (
Date: Tue May 03 1994 - 11:23:11 EDT

> time, then you will, in fact be sending a pure frequency. But you cannot
> modulate a carrier *in any fashion whatsoever* without generating sidebands.
> The sidebands generated by a CW transmitter look suspiciously like very thin
> AM sidebands, and if you think about it, that's exactly what CW modulation is.

That may be true, but only because you cannot perfectly turn on and off
the carrier. Still the ideal desired signal IS a single frequency.

> that expensive commercial transceiver you're talking to will have your carrier
> outside of *its* sideband filter, because it looks to him like you're sending
> on "the wrong sideband" (think of sending MCW using an SSB rig). Two DC

Not. Go ahead and set your rig to USB and tune in a CW signal. Now set
your rig to LSB and retun in the same CW signal. There is no way in the
world you can tell the difference, expect if your getting interference from
another station on either side.

> on "the wrong sideband" (think of sending MCW using an SSB rig). Two DC

My previous comment is also true for MCW on an SSB rig. It sounds
identical to a true cw transmitter (well signal may not be quite as pure).
On a DC receiver you will hear a tone on both sides of the beat signal, on
an SSB receiver you will hear a perfect signal on whichever side your cw
mode uses. You absolutely cannot tell the difference.


Mont Pierce

+-------------------------------------------------------------------------+ | Ham Call: KM6WT Internet: | | bands: 80/40/20/15/10/2 | | modes: cw,ssb,fm | +-------------------------------------------------------------------------+

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