[Lowfer] CFH info

[Mitch Powell]

Greetings:  F  Y I
Just saw this on the Sept. issue of "Monitoring Times: and might explain some of the CFH LW
testing that has been observed ?
73
Mitch

CFH Update

Last month, this column reported that CFH, the large Canadian Forces station in Halifax, NS, had changed its channel availability markers. Sud­denly, they’d switched from radioteletype (RTTY) to a newer phase-shift keying mode called STANAG 4285. The latter name comes from the military standard used, Standardization Agreement number 4285.
This was true at the time, but at least right now as we go to press, they’ve changed it back. Yes, the markers, sent on assigned frequencies of 5097, 10945, and 15920 kHz, are back in plain old Baudot RTTY as if nothing had ever happened.

The RTTY parameters remain the same as before any of this changed. Speed is 75 baud, and shift is 850 Hertz. When tuned in USB (around 2.2 kHz below assigned channel center), the signal idles on the lower tone of the frequency-shift keying pair. Every 30 seconds, a marker similar to this one is sent in the International Telegraph Alphabet #2 (ITA2): “NAWS DE CFH ZKR F1 2822 3394 4158 6242 8324 12371 16552 AR.”

Check last month’s column for details on what all this means. Suffice it to say that it’s a list of available channels on which warships may call CFH. Many militaries in the North Atlantic Treaty Organization (NATO) send these, in one form or another.

Will CFH go back to STANAG 4285? Well, stay tuned.
 
ZKR*  I am (or ... is) maintaining watch on                    

On what frequencies are you... kHz (or MHz).(or ...) maintaining watch ?

 
 Part 2

 
Canadian Forces Using STANAG4825

For a brief time during early June, all of CFH’s regular 75bd/850 RTTY channels con­verted over to the STANAG4285 HF modem with 75bps data rate and long interleaving. The same NAWS (Notice to Allied Warships) text was sent.

Frequencies used were the expected 1800 Hz below the usual center of data point, i.e. 5095.2, 10943.2 and 15918.2 kHz USB.

This event caused much discussion on the UDXF forum, where utility listeners lamented the loss of yet another RTTY transmission in the clear. However, the loss was only brief and the stations were back to RTTY after a few days in the digital domain.