locked Re: 60 meters: Operating guidelines for FT8


Hasan Schiers N0AN
 

From the ARRL:
These are channel-center frequencies, not the ones you tune your radio to. The NTIA told the FCC that hams "must assure that their signal is transmitted on the channel-center frequency." This means the amateur signal must be centered within the 2.8-kHz-wide channel. The FCC has provided scant guidance beyond suggesting--in a footnote that follows the NTIA's advice--that amateurs tune 1.5 kHz below the center-channel frequencies to be "on channel." Amateurs need to be sure that the tuning display readout reflects transmitted (ie, carrier) frequency (most do). Consult your transceiver's manual if you're not sure.

From the ARRL:
In addition, the FCC continues to require that all digital transmissions be centered on the channel-center frequencies, which the Report and Order defines as being 1.5 kHz above the suppressed carrier frequency of a transceiver operated in the Upper Sideband (USB) mode. This is typically the frequency shown on the frequency display.

(Note that this does not say 1580, 1320, 700, ...it says 1.5 kHz) my comment, not ARRL's)

http://www.arrl.org/60m-channel-allocation
"Operating at strict channel-center frequencies may come as a disappointment to many, but cooperating with the NTIA is key to expanded privileges in the future.
The channel center frequencies are":..snipped...60 meters

"Only one signal at a time is permitted on any channel." (From ARRL Band Poster)
http://www.arrl.org/files/file/Regulatory/Band%20Chart/Band%20Chart%20-%2011X17%20Color.pdf

More on Center of Channel ( 1500 Hz) Requirement:

"With your PSK31 software display configured to indicate audio frequencies, click your mouse cursor at the 1500 Hz mark (see below). With your radio in the USB mode, this marker indicates the center of the channel and it is the frequency on which you should be transmitting."

There is no special exemption for FT8, the same center channel rule applies.

In Summary from the ARRL:

1. Only one station may transmit at a time.
2. They must be at he CENTER of the allocated channel (1500 Hz)
3. NTIA has defined "on channel" as precisely 1.5 kHz below the assigned channel frequency.

These are highly restrictive and have NOT been enforced. I posted my initial "Be Careful" message, because I was warned by someone familiar with the upcoming ARRL take-over of the FCC certified Monitoring Program, that once the new program had officially started : ENFORCEMENT WOULD BE FORTHCOMING and the enforcement will include referrals to the FCC for action.

Unfortunately, the comment below reflects the attitude of many USA amateurs:

 "If the FCC is that concerned about legitimate FT8 use within that 2.8 KHz BW, they need to clarify their own rules and rationale and make this clarification known.  Because right now, its as clear as mud.  "Field Day" for lawyers, so to speak."

As a result,  the 60m requirements for digital, (FT8 included), have been summarily ignored if not outright violated. I, myself did so, because I did not understand how one could reasonably operate a full SSB bandwidth and that was ok, but could not use the entire 2.8 kHz bandwidth for multiple narrow band FT8 transmissions. It makes NO sense. But....the rule is unforgiving and I have been told they are going to enforce it.

I have advocated one thing and one thing only: Be Careful. I don't have horse this race. It would be a shame, however, if we lost this allocation or someone would get a QSL card from the FCC because they refused to exercise some caution in the matter.

73, N0AN
Hasan


On Thu, Feb 20, 2020 at 5:41 AM Seannon Baker (AG0NY) <KD4IYI@...> wrote:
Also, it clearly states that no more than one station transmit at any given time thus also limiting to a conversational rather than a transactional contact type. (If you hear a conversation, don't transmit, if you hear a CQ, answer it unless you hear someone else answering)


Seannon, ag0ny

On Thu, Feb 20, 2020, 05:15 Nc8q-mesh@... <nc8q-mesh@...> wrote:
On 2/20/20 5:17 AM, Hasan Schiers N0AN wrote:
Again, ARRL have *on multiple occasions* reported communications from
FCC Enforcement staff (and NTIA who are responsible for the "60 M
band") reminding US licensed amateurs that 97.303(h) requires using
*identical* audio frequency and carrier offsets so that the transmitted
signal is centered exactly on the middle of the assigned "Channel" -
not generating a random offset within a 2.7 KHz "band".

IMHO, this discussion of operating FT8 on 60 meters deserves its own thread.

 From looking at the waterfall display (Wide Graph),
it seems to me that a FT8 Tx frequency of 1500 indicates signals from
'dial frequency + 1500 Hz' to 'dial frequency + ~1548 Hz'.

The get TX signals centered on 1500 Hz,
 would it not require setting WSJTX to 1476 Hz ?

Chuck



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