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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