What is all comes down to is the fact that if EVERY op spots the freq, as
seen on the waterfall, then there would be no question about where the
station spotted actually is. Every software package that I have used for
digital ops has worked the same way. If you spot 14.0713567 or whatever,
and I click on it, that signal will pop up at 14.713567, directly where the
software reads it, and I dont have to wander around, wondering which of a
dozen or more signals on the waterfall is actually the correct one. We all
underrstand that there is still a possibility of a slight error and the
signal may be a few cycles off (10-20, etc,) but still close enough you wont
mistake another signal for the spotted one, and if you use agc it will
instantly zero beat the correct one. If you spot the station at 14.070,
that is where my waterfall winds up, and the station is NOT there, nor
anywhere close. Your offset doesnt matter to me, nor mine to you.
Spotting the station at "14.070 plus 1000" at least advises other ops where
the station actually is, but doesnt permit others the "one click and on
freq" capability built in to software packages. My present sound card does
have the sweet spot (offset) at 1 KC, but its only one of the last 4 sound
cards that did so. Others have been 600 cy, 1200 cy and 865 cy. Anyone
spotting a freq at 14.070 will thus lead different ops, using different
computer sound cards, off by whatever THEIR offset is.
I know that some folk do not have CAT software at the time, but I believe
every new rig has the capability, and you need only one patch cord to run
from the computer to the rig to activate that, and the majority will have,
if not already, CAT control of their rigs. Things are quickly changing and
we need to bend a little to go with the flow. Boy - it sure makes things
quicker too.
Danny Douglas N7DC
ex WN5QMX ET2US WA5UKR ET3USA
SV0WPP VS6DD N7DC/YV5 G5CTB all
DX 2-6 years each
.
QSL LOTW-buro- direct
As courtesy I upload to eQSL but if you
use that - also pls upload to LOTW
or hard card.
moderator [EMAIL PROTECTED]
moderator http://groups.yahoo.com/group/DXandTalk
----- Original Message -----
From: "Rick" <[EMAIL PROTECTED]>
To: <[email protected]>
Sent: Tuesday, May 29, 2007 10:07 AM
Subject: [digitalradio] Offsets for digital modes
> Paul,
>
> When you are on CW, many rigs will have an offset. I have an Argonaut V,
> and, as you noted, you can set the offset tone for your preference. That
> way you are zero beat with the other station and yet you can adjust your
> sidetone to what works best for you.
>
> With RTTY, the frequency specified was typically the mark with rigs
> using FSK. That is why there was some confusion from some hams who may
> be operating AFSK since their dial frequency on AFSK is going to be
> quite different than the dial readout on FSK. This is mostly dependent
> on how your rig is designed.
>
> For example, on my ICOM 756 Pro 2, if I zero beat on AFSK using SSB and
> then switch to FSK, it will place the tones with the mark tone of 2125
> Hz. If I try to zero beat in RTTY mode, I would be over 2 KHz off. If I
> try to zero beat in CW I would of course be off by whatever offset I
> programmed into the rig, which in my case is going to be around 600 Hz.
>
> If you are using a sound card mode, you will be injecting tones into an
> SSB transmitter. The dial frequency is actually reading out your carrier
> frequency, but of course with SSB, for all practical purposes, there is
> no carrier being transmitted. The dial frequency is only a place holder,
> it is NOT the actual frequency you are transmitting. The actual
> frequency you are transmitting depends upon the frequency of the tone
> you are injecting into the transmitter and whether you are using USB or
LSB.
>
> When you are operating SSB, whether on your Drake or your Ten Tec rigs,
> and you place your "carrier" at a given frequency (dial frequency) and
> inject the same tones, you can expect to be transmitting at the same
> frequency with either rig. If you set either rig at 14.070, and someone
> else sets their rig at 14.070, and you both use the same audio frequency
> tones, you would each be on the same frequency.
>
> The only problem that comes up is that someone will claim they are on
> 14.070 and inject a 2000 Hz tone into their transmitter and of course
> they are really on 14.072 and may be difficult to locate if the
> receiving station expects them to be on 14.070. By specifying the
> offset, such as 14.070 + 1000 Hz, you can expect that they will be 1000
> Hz higher than 14.070 and if using a waterfall display can pinpoint them
> quite accurately.
>
> Some of the new modes are quite wide and are expecting that the tones
> are going to be within a given standard bandwidth of frequencies since
> they take up much of what we normally considered to be a voice bandwidth
> (e.g., 141A FAE, MT-63, SSTV). In such cases, when someone says they
> will be on a given frequency with these modes you can expect that both
> of you will use the same dial frequency and the tones will be placed
> correctly in your passband of the rig.
>
> 73,
>
> Rick, KV9U
>
>
>
> Paul wrote:
> >
> > What is the designation of 10.140 + 1000Hz? When I've looked at band
> > plans I sometimes see 20M psk designated as 14.070.150 More often it
> > is 14.070. When I tune, I tune to 14.070 with a Ten Tec Argo and
Pegasus.
> >
> > However, the Drake is different. It doesn't accomodate the offset. For
> > example, on the TT, if I have my sidetone set to 600Hz, and a cw
station
> > is on 7.100, I tune to 7.100 and hear him with a 600Hz note. With the
> > Drake, I'd have to tune to 7.100.6 (or 7.099.4?) to hear the station
> > with that tone.
> >
> > So with 10.140 + 1000 I'm guessing with the Ten Tec I'd tune to 10.140
> > USB but with the Drake I'd tune to 10.141 USB. Is that how it goes?
> > If so, why is it 1000hz instead of 1500Hz?
> >
> > Thank you and 73,
> > Paul
> >
> >
>
>
>
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