By way of introduction, I am of the FT8 operators for the upcoming KH1 DXpedition. I am also the one who suggested to the WSJT development team to use 14105 for this one-time, two-hour test yesterday. The initial round of testing on the new DXpedition submode held on 6 March was conducted on RTTY frequencies during the week to minimize interference to those who use that mode. Having studied the frequencies in use on 20 meters in the digital subband, it is clear that there is no unused 4 KHz segment for any new mode to use without some interference to some existing group of digital operators. Our honest attempt was to minimize interference as much as possible for this one-time test.

Let me tell you and everyone else on this development reflector that there are two actions in process related to frequency use for the FT8 DXpedition tactical in nature and one more strategic.

Tactical activity:

The KH1 team is currently settling on the frequency plan for the DXpedition. The team will activate the very rare DXCC entity between 27 June 2018 to 7 July 2018. Keep in mind that this DXpedition is in the middle of summer in the Northern Hemisphere and at/near the bottom of the solar cycle. As a rsult, not many bands will be open and a most of our activity will be on only a few bands at any given time. There are no planned RTTY contests during the time when we will be active on the island and as a result, we will plan on using frequencies that are often used in RTTY contests for the FT8 DXpedition mode operation. Our primary goals in frequency selection for FT8 and all other modes is to minimize interference to non-DXing segments of the band, minimize the inter-station interference to our three operating tents in the island, and to maximize the positive experience for all operators who wish to work us. We will have eight stations on this DXpeditions and 18 operators. Two of the stations (in the DIGI tent) are dedicated for digital modes and others can be configured for FT8 if it is determined to be the right thing to do. Our objective is to use FT8 DXpedition mode to reach the largest group possible of new and veteran HF and 6 meter operators using this exciting new mode.

Strategic activity:

The WSJT development team with my support and those of other digital mode operators are launching a campaign to assess the current band plans for all IARU regions. Clearly, the game is changing and activity in the digital modes on the amateur bands is on the increase and it would be prudent to begin the process of mapping the way forward to use the amateur spectrum in the best way possible. This process will take some time but must start now. There will be changes in band plans in the future, undoubtedly, but we must continue to operate with the objectives of minimizing interference until then. If the KH1 activity on the DXpedition mode is successful, it might act as a model for DXpedition mode use in the interim.

The KH1 frequency plan on tour website is being updated, but will be widely published soon. Hopefully we can conduct any future tests or practice sessions on those FT8 DXpedition mode frequencies in the plan to be sure we have it right before we create havoc while on this upcoming DXpedition.

73 and thanks.

Ned / AA7A

On 4/8/2018 1:50 PM, Deplazes Gion wrote:

Hi dear OM’s

Now I subscribed and try again to send you this message.

Tnx 73 HB9HAE

*Von:*Deplazes Gion <>
*Gesendet:* Sonntag, 8. April 2018 11:34
*An:* '' < >
*Betreff:* FT8 DXpedition mode /interference other digital modes

Dear Joe, dear OM’s,

Thanks very much for  the information on the new FT8 mode and the carefull testing.

I appreciate it very much that you welcome suggestions to minimize interference with other digital modes.

Indeed there might be a problem on 20 m band :

For years we are using 14‘104.5, 14‘105.5, 14‘106.5 , 14‘107.5 and 14‘108.5 center frequency in olivia 32/1000  world wide also for longer chats.

Olivia is mainly a low power mode, with current condx we also need sometimes more power.  So i expect interference.

 I would kindly ask you, if you could move your frequency  slightly away and i think the whole olivia comunity would be much obliged.

Best regards from a intense user of all kind of digital modes.

Gion D. Deplazes


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