Re: [wsjt-devel] Idea for "frequency hopping" FT8 to reduce collisions

2021-08-30 Thread Bill Frantz via wsjt-devel
On 8/29/21 at 5:04 PM, wsjt-devel@lists.sourceforge.net (jan0 
via wsjt-devel) wrote:



The original problem Phil was trying to solve, of course, was the 
repeated-collision problem in FT8.


A few observations:

Wider bandwidth receive may be limited by the available 
antennas. While most antennas will give decent coverage to an 
entire ham band, some will not. (e.g. Highly loaded antennas 
like a Little Tarheel on 80M.) Trying to decode more than one 
band with e.g. a SteppIR antenna may push the signal strength 
too low on the non-tuned band.


Claude's observation that we only have local information it 
real. I remember during a RTTY contest noticing that there were 
two stations CQing on the same frequency, one tuning permitted 
decoding both of them. I don't think they knew about each other 
because they were in each other's skip zone, but I could decode 
both of them and worked both of them. Skip zones will apply to 
FT8 as well. Listen before transmitting has its limits.


Another way to address this problem is to stop in the middle of 
a 12+ second transmission to check the transmit frequency for a 
short time. If this is automatic, the pause can be quite short. 
When I do it manually, I have to listen for longer. Since FT8 is 
designed for weak signal work, it can handle short dropouts. 
Even with manual listening I frequently get the message through 
in spite of the dropout.


73 Bill AE6JV

---
Bill Frantz| There's nothing so clear| Periwinkle
(408)348-7900  | as a design you haven't | 150 Rivermead 
Rd #235
www.pwpconsult.com | written down. - Dean Tribble| Peterborough, 
NH 03458




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Re: [wsjt-devel] 2.5.0rc5 and FT4 PTT

2021-08-30 Thread Saku via wsjt-devel


Black Michael via wsjt-devel kirjoitti 27.8.2021 klo 18.22:
Those cache times are showing 10134ms = 10 seconds since the last time 
ptt was polled.  For FT4 that's not good.


What is your polling rate in WSJT-X?

Mike W9MDB


Hi MIke!

Poll rate is 5sec. Compared to FT4 period it is too long, but I expect 
that every needed command is placed at time it should happen (not placed 
in poll queue) and reply for sent command comes immediately and at all 
other times (when not any special job to execute) rig is polled by poll 
rate.


But if every rig cat command sent and responded go via poll queue then I 
just wonder how it has worked this far from the beginning of FT4 mode.


I'll try next to minimize the poll rate and see what happens.


--
Saku
OH1KH



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