Comments inline...
On Saturday 01 May 2010 02:59:13 pm Anony Mous wrote:
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.
Exactly.
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.
Yes, just shut off the display.
2. The frequency display on the radios is almost never the actual
frequency of the transmission.
Correct and the Fldigi frequency display in question isn't intended to display
the actual transmitted frequencies. Although this is an area that
inexperienced and untrained hams always have trouble with. Again, it's a
training issue. Hams need to know what the software and hardware they are
putting on the air is doing. It's not idiot proof and never will be.
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.
The radio dial frequency is the readout in Fldigi. The AFSK waterfall
frequency, added to that radio dial frequency, for the various audio tones, is
the frequency, or frequencies, of actual transmission. The operating ham needs
to know this. Many times it is not a single frequency, but several or a range.
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.
Yes.
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.
For one thing, it's live. It controls the radio remotely if you have CAT
working. It's a confirmation where the radio dial is set. I rarely touch the
radio when doing digital. You don't need to.
Request: I would like the option of having the main fldigi display
show the actual transmission center frequency for the mode.
That is not and never was it's intended purpose. It is designed to control the
CAT of the radio, and/or to indicate the carrier reinsertion frequency of the
rig, for waterfall audio frequency addition or subtraction for logging.
Besides, for some digital modes the frequency stated for nets and skeds is
definitely *not* the center frequency of the tone(s) transmitted. For some it's
the start tone, or the others the mark tone.
You are missing the entire intended purpose of the display of frequency. It
would appear for your purposes maybe you need to just shut it off.
It works as intended and that operation is clear to anyone who has taken the
time to read the manual and to understand how the digital modes that they are
transmitting work.
Being inexperienced is no substitute for knowing what you are doing with any
transmitter you are controlling.
Again, this is a training issue. Get the operators trained so that they know
what they are doing and more importantly where their transmitted signal is
going.
Rick Kunath, k9ao
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