On Sat, May 1, 2010 at 12:35 PM, Brian Lloyd <[email protected]> wrote:

>
> Two points here:
>
> 1. If you have two displays, they should display the same thing if
> they are supposed to display the same thing. Anything else is
> confusing to the operator.
>

That's why you should be able to turn the fldigi display off, as point was
made earlier. It's duplicated data, potentially a slowdown/confusion to the
operator. The radio is on the frequency it says it is, that's all anyone
needs to know.


> 2. The frequency display on the radios is almost never the actual
> frequency of the transmission.


Uh, no. If I'm tuned to 14.230 MHz on the radio, and I'm receiving a FAX
signal that is AFSK between 1500 Hz and 2300 Hz, then the transmission is,
in fact, on 14.230 Mhz - the "center" (1900 Hz, or 14.2319 MHz) is not only
*not* where the radio is tuned, if it *was* tuned there (you'd have to
offset the fax modem to do it), then if the operator of the transmitter were
to speak up and tell you "that was a fax of the important document you asked
for", you wouldn't be able to understand them, because you're incorrectly
tuned. Furthermore, if you were to send a fax back, you typically want the
radio on 14.230 as well; otherwise, you have to operate split.

The correct frequency IS the frequency the radio is tuned to. Not whatever
fldigi calculates as the modem center. This stuff is AFSK. Note the AF.

There are numerous reasons to receive signals at the tones they were
designed to be sent at. If you have external gear of almost any kind, RTTY,
packet, SSTV, FAX, etc, they're going to be expecting very specific AF
tones. The tones you'll get when your radio is tuned appropriately, and when
the signal falls on the AF indications on the waterfall that are the design
points for the mode - for FAX, that's 1500 hz and 2300 hz. For SSTV, 1200,
1500...2300 Hz. For RTTY, etc.


> Fldigi does calculate and display the
> actual center frequency only in the log window.
>

It's a misleading number at best. The correct frequency is the one the radio
is telling you. For optimum operations, the waterfall should be set to AF,
the modems should be at the design points, and the frequency display is
misleading and/or duplicates the radio display, consumes UI space that could
be better used for something useful, and should probably be disabled as a
direct consequence. Speaking of any situation where we are not just
entertaining ourselves, but are working in circumstances where correct
operation may have social or human consequences. There is no benefit to
fldigi's frequency display when it is duplicating the radio's; there is no
benefit when it is displaying a misleading "center frequency," either. If
you were using it to preview fldigi memories, that I can see. Otherwise... I
have yet to be presented with a point in its favor.


> Request: I would like the option of having the main fldigi display
> show the actual transmission center frequency for the mode.
>
> --
> 73 de Brian, WB6RQN/J79BPL
>
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