[RTTY] IARU and 14100 Beacon QRM from Digital Signals

[Michael Keane K1MK]

At 09:40 PM 10/1/06, Bill Coleman wrote:

>On Oct 1, 2006, at 9:15 PM, John Becker wrote:
>
> > If you dial says 14,002 both your mark and space will be out of
> > band.
>
>We're both on the same frequency, because our mark and space signals
>are on the same frequency. Our radio dials will just read differently.

The reason the dials would be reading differently is because the 
radios have not been calibrated to display the mark frequency, which 
is the convention for RTTY operation.

On older radios we'd do that manually using the dial zero and the 
crystal calibrator  in conjunction with the tuning indicator on the 
TU. Many modern radios can be set to take into account the mark tone 
being used and display the correct mark frequency when switched into 
the FSK (or AFSK) mode.

Anyone who uses the spotting network for RTTY does need to remember 
that it's always the mark frequency that's spotted, never the "dial 
frequency" or something else.

73,
Mike K1MK

Michael Keane K1MK
k1mk at alum.mit.edu