[Elecraft] (K3) RTTY offset ?

[Richard Ferch]

Hello Adriano,

You didn't say whether you were using FSK D or AFSK A, or what software 
you were using. I will assume that when you say "on the scope" you mean 
on the waterfall in software such as MMTTY.

If your radio is in FSK D, then it can receive on any frequency within 
the filter bandpass, but it can only transmit on one frequency - the one 
corresponding to the PITCH setting. If you click on a signal in the 
waterfall to receive it, the frequency you choose in the software's 
waterfall will probably not be the same as the one the radio will 
transmit on. If you use the K3's MONitor function to listen to your 
transmitted signal, you can hear whether the transmitted and received 
frequencies are the same.

Depending on the software you are using and its capabilities, there are 
advanced methods to use mouse-tuning and AFC in FSK RTTY, but the 
simplest solution to this problem is never to use clicking in the 
waterfall to find a signal when you are using FSK. If you are CQing, you 
can use AFC to let your receiving software tune in callers who come back 
slightly off-frequency, but when you are planning to call someone else 
who is CQing you should turn AFC off. In MMTTY, you can use the HAM 
button to ensure that your receive frequency will be the same as your 
transmit frequency. You should configure the HAM default to be the same 
as the radio's PITCH setting.

If your radio is in AFSK A, it can transmit on the same frequency it 
receives on, although the best frequency for both transmitting and 
receiving is the one in the PITCH setting and the HAM button. If you are 
using MMTTY software the easiest way to ensure that your transmit and 
receive frequencies are the same is to turn NET on. With NET on you can 
safely use mouse-clicking to tune in a signal to work. However, if you 
are calling CQ you should turn NET off, and use the HAM button before 
your first transmission to establish your transmit frequency. If the 
other station comes back off-frequency you can use AFC or a mouse-click 
to copy the other station's signal, but as soon as the QSO is completed 
you should click on the HAM button to return to your original transmit 
frequency.

73,
Rich VE3KI


PY2ADR wrote:

> Trying to config k3 on digi modes but i noted a "offset" between rx and tx ...
> When i find a sig on the scope i click on it and the rx is ok. Then i go tx and the \
> station comes back in another qrg. Or when i call cq the stations comes back in \
> another qrg....