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.
2. 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.
3. 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
------------------------------------------------------------------------------
Check out the vibrant tech community on one of the world's most
engaging tech sites, Slashdot.org! http://sdm.link/slashdot
_______________________________________________
wsjt-devel mailing list
wsjt-devel@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/wsjt-devel
