N1NB wrote:
> Regarding RTTY on Mark V I run FSK FB . But had to reverse the RTTY
> Polarity (Menu item 6-1) to get a signal the was Not reversed! There
> appears to be no convention for rigs & software as to which is Mark and
> which Space when "tugging" on a Shift pin.
It appears so.
Both the FT-990 and the FT-1000MP share the same keying polarity,
and are opposite to that of the interconnect standard used by the
TenTec Omni V and VI (and, by the way, the KAM).
Both of my Yaesu rigs are switched to "reversed" just to comply
with all the other stuff in my shack.
To paraphrase someone in the computer world, the nice thing about
standards is that there are so many of them to choose from :-).
As long as Mark is the higher frequency on the RF spectrum (on
the audio spectrum, it is the lower of the Mark/Space tones, i.e.,
2125 Hz if you are using the 2125/2295 pair, but LSB modulation
reverses the order on the way to becoming RF).
If we are watching a tuning indicator while a station is
transmitting diddles, Mark is the frequency which appears more
often than the Space. And the Mark frequency should be the higher
frequency of the Mark/Space pair on the RF spectrum.
The Mark frequency is also the frequency all nice guys spot
RTTY DX on the Packet Cluster. Here, the Yaesu rigs are nice
in that you can set a menu or a switch to make the dial read out
the Mark frequency.
73
Chen, W7AY
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