[RTTY] Frequency Accuracy

[Tom Osborne]

If there is a QSO going on where they are going to send their bulletins, 
they don't just fire up and go right on top of the QSO that is going on, do 
they???  They should be a little bit off if they obey their own rules and 
don't transmit on top of someone else.  73
Tom W7WHY


>
> John,
> W1AW is often not on the exact frequency they claim. Please check on only
> WWV. They are always right on the "money".
> Bob, W6CYX
>

I agree with Bob W6CYX; however, the W1AW RTTY bulletin is where I check my 
frequency calibration for RTTY.  I have been in touch with the W1AW station 
manager and he indicates they are  rock solid on frequency in CW mode; 
however, they have had some frequency offset issues with digital modes. 
These offset issues with a custom version of the MixW software used by W1AW 
have been resolved.

On 15-Aug-2011, I ran a test using my Kenwood TS-590S with the SO-3 TCXO and 
the new version of fldigi-3.21.12 by W1HKJ that now reports and logs the 
RTTY Mark while in AFSK. As a backup I ask Dick K4JJW to listen and record 
the W1AW RTTY bulletin using his Icom IC-7700 using MMTTY in FSK mode.

Before conducting the test I calibrated my TS-590S to WWV using the fldigi 
Frequency Analysis tool and ran into some issues with what may be a 
defective Kenwood SO-3 TCXO; however, I did manage to get the TS-590S 
calibrated pretty close to the WWV signals on 5, 10, 15 and 20 MHz. The 
suspect SO-3 is another discussion topic.

As expected the W1AW RTTY signal was very easy to detect and decode.  I 
moused on the signal on the waterfall display and accepted the fldigi 
reported "QSO Freq" (RTTY Mark) and read 14095.020 which I though was close 
enough for amateur use. W1AW broadcasts in AFSK with an offset such that 
listeners with rigs in FSK mode should copy the W1AW signal at 14095. 
Shortly after the test, I got an email from K4JJW that he copied the W1AW 
signal at 14095.020 in FSK on his Icom IC-7700

What is amazing about the the test was getting a Kenwood TS-590S user in 
AFSK mode on a Mac and Icom IC-7700 user in FSK mode on a PC to AGREE on a 
RTTY frequency!

WWV is great for calibration but for quick checks I copy the W1AW RTTY 
bulletin.


73 Dick AA5VU



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