[RTTY] ARRL's WinLink initiative and Pactor III

Phil Duff NA4M na4m at arrl.net
Wed Aug 11 15:18:05 EDT 2004


At 06:03 8/11/2004, Thomas K wrote:
>Since you have not realized YET that those PACTOR-III stations are out there
>... you should not have a problem !!!!

Yes - that's why I asked.  I've never been interested in operating any of 
the 'TOR modes so don't know much about their operations.

Research indicates that apparently Pactor III is operating in limited sub 
bands:

Use of Pactor-III protocol is limited for US hams and some other countries 
due to the very wide bandwidth of the Pactor-III signal. Presently digital 
signals that occupy the bandwidth of PCT-III are restricted to a few sub 
bands:
28.120-28.189 MHz, 24.925-24.930 MHz, 21.090-21.100 MHz, 18.105-18.110 MHz, 
14.0950-14.0995 MHz, 14.1005-14.112 MHz, 10.140-10.150 MHz, 7.100-7.105 
MHz, or 3.620-3.635 MHz.

>I think Pactor-III has been availiable for about more than 2 years now !
>Seems that they are operating outside the standard RTTY-freqencies.

Yes maybe - if Pactor III stations are adhering to the frequencies above 
then there should be minimal conflict with RTTY operations, except perhaps 
21.090-21.100 and 14.095-14.0995 can be heavily used by RTTY in major RTTY 
contests.

I have been told that the ARES/EMCOMM PACTOR stations have been directed to 
NOT configure themselves as PMBOs which is good.

Additional information I researched regarding FCC regs and Pactor III:

""A 4800 baud digital code may not legally be transmitted below 50 MHz, as the
rules are currently written.  The limits on HF are 300 baud on all bands but
10m, and 1200 baud on 10m."

"In 1995 the FCC relaxed the rules concerning what sort of digital codes 
could be used. To
paraphrase, the "new" rule states that any code is legal AS LONG AS IT IS
PUBLICLY PUBLISHED. That's the catch with PACTOR III--its code is NOT
published. The company that makes the PACTOR III controllers (SCS) has
refused to release the code details."

I wonder if the Pactor III protocol/code been published yet?  If not it 
would seem that PACTOR III is not legal on the HF bands in USA?

Has anything changed in the FCC regs to address the 300 baud limitation or 
closed protocol issues???

My concern is if there becomes a large number of ARES/EMCOMM stations on HF 
running PACTOR III will they stay within these narrow sub bands or spill 
out from those frequencies and cause problems for RTTY and/or other digital 
modes.

73 Phil NA4M


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