Grant,

I am thinking that it is reasonable interpretation to consider CQ message, i.e. 
“CQ, CQ EU, CQ NA, CQ AS…..” is our “paging message” or “congestion control 
message” to allow certain group to send their access message such as “KH1/KH7Z 
JA5AEA PM95” at access channel i.e. above 1,000Hz~4,000Hz. However, the power 
should be limited to the minimum power to be able to communicate at individual 
message exchange as I said. However, CQ period should not be fixed and it 
should be only transmitted when “QSO queue” is becoming empty. (I think  this 
type of information is described in FT8 DXpedition Mode User Guide)

Well, for JA wise, KH1/KH7Z is the first exposure to DX Pedition Mode without 
any trial opportunity, so, it is a fan to see the windows in WSJT-X and imagine 
what we should do next.

Yes, It may be the time to wait the chairperson’s summarization and for a 
while, we should  chase KH1/KH7Z last day operation. I am expecting they will 
expand their service at high and low bands.

Regards,

take

de JA5AEA

Sent from Mail<https://go.microsoft.com/fwlink/?LinkId=550986> for Windows 10

________________________________
From: Grant Willis <vk...@bigpond.com>
Sent: Tuesday, July 3, 2018 7:05:09 AM
To: 'WSJT software development'
Subject: Re: [wsjt-devel] Observation on Expedition Mode

Everyone,

The thread hi-jacking has been interesting but time to bring it back to my 
original question perhaps please?

Take,

Yes – the problem with varying power is I might hear him CQ when he transmits 
with only one channel but when -14dB of power reduction results from 5 
responses I could loose him )and did do so several times). The CW and the power 
of the channels I am listening to of him calling everyone else needs to remain 
constant as an individual channel otherwise this wildly varying link budget 
just breaks contacts.

A worthy modification would be to resolve the varying individual channel power 
dilemma I feel. I would be interested in Joe and Steve’s thoughts on this?

Regards,
Grant VK5GR

P.S. The CQ calling is nice – and KH1/KH7Z could make better use of it and free 
text to control their pile more – but blocking people calling as proposed by 
others here until certain preconditions are met – based on my observations of 
the traffic patterns I don’t see it helping the situation at all.

From: Tsutsumi Takehiko [mailto:ja5...@outlook.com]
Sent: Monday, 2 July 2018 3:09 PM
To: WSJT software development
Subject: Re: [wsjt-devel] Observation on Expedition Mode

Grant,

Allow me to write my comment on your topic as I have same topic interest 
writing “FOX adaptive power control” in this thread.

Concerning your proposal, i.e.“to have the setting of number of channels vs the 
number of active channels maintain a constant PER CHANNEL TX power”

My comment is


  1.  When fox sets 5 slot mode and it activates 5 slots, the average power per 
channel is -20*LOG(5) dB=-14dB. This means about 20W per channel if fox uses 
500W linear.


  1.  When active channel is actually 1 slot, What does fox obtain the benefit 
to maintain link with a particular hound keeping 20W instead it can transmit 
500W?  Please keep in mind fox uses his channel to send his message to 
particular fox such as “VK5GR KH7Z -05”, “VK5GR RR73”. It is not the messages 
to me JA5AEA.



  1.  Instead,  I agree to keep CQ message to be fixed, i.e. 20W as this is a 
broad cast message. If fox sends 500W, it is disastrous. (KH1/KHZ may be 
confusing us and creating lengthy arguments by this high power CQ feature??)

Regards,

take

de JA5AEA

Sent from Mail<https://go.microsoft.com/fwlink/?LinkId=550986> for Windows 10


________________________________
From: Grant Willis <vk...@bigpond.com>
Sent: Saturday, June 30, 2018 9:47:02 PM
To: 'WSJT software development'
Subject: [wsjt-devel] Observation on Expedition Mode

Joe,

An observation if I may about expedition mode. I see with KH1/KH7Z that the 
number of Fox TX channels varies – I presume as they place more stations in the 
queue. As expected, the power per channel drops the more channels running so 
that the amplifiers can keep up. However, this has an unintended consequence 
perhaps of potentially breaking QSOs. A few times now I have started calling 
KH1/KH7Z on 20m when I am receiving them around -09 (but with pretty low 
S-meter  signal strength). Usually this is with 1-2 channels running on their 
downlink. If they go to 3 channels I can still receive but it falls to say -15. 
If they bring up channel 4 and 5 I loose them. There just isn’t the link budget 
left to receive them when the power is split between more than 3 channels in 
this example.

Now the issue is, if they answer me by adding the 4th channel – I wont hear 
them under those conditions. If I am part way through a QSO I can loose the 
RR73 for the same reason if they answer someone else on the 4th channel– simply 
because the link runs out of steam.

Now if I couldn’t hear them in the first place I wouldn’t have tried calling. 
In this case however, they can disappear under load effectively and I loose 
them mid QSO.

For future consideration perhaps is to have the setting of number of channels 
vs the number of active channels maintain a constant PER CHANNEL TX power 
rather than the variable situation we have now. Ie I enable my fox station to 
run say 4 channels, but only reply on 1 channel, then the output power should 
be the equivalent of the power that would be in that channel if all 4 were in 
fact on air but aren’t. At least that way I have a constant link budget I am 
working with on my comms channel with the fox station rather than one that can 
have them drastically cut power mid QSO without reference to the conditions on 
the path I am working them via.

If what I am describing is not how it is supposed to work already then there is 
another factor at work somewhere in the chain to be explored. I would be happy 
to discuss this further and use the KH1/KH7Z expedition to observe and learn 
more about how the multi-channel nature of the mode works.

Regards,
Grant VK5GR

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