Thanks Joe,
Well, the QRN on LF is quite different to that on HF. So probably the
optimised parameter settings (to be found) will be quite different as
well. As a spontan idea, maybe the program should allow to choose the
band which we are receiving on and the program will use specific NB
settings, different on LF compared to HF.
For serious (serious is relative) LF DX, JT9-10 and JT9-30 will be
preferred, also in contrast to HF. So i think i'll go on in these modes
and RX stations may collect some wav recordings for future anylysis.
I'll enable "Save all" as well here.
I'll try to run WSJT-X at YV7MAE in FK81BD as well, this night in
JT9-30. It may be a bit to optimistic to expect a decode though.
73, Stefan/DK7FC
PS: Another idea: If there are some RX stations who like to do some
tests, we could try to run 2 instances of WSJT-X, one with and one
without the NB. Maybe it requires to install the program twice, in
separate folders
Am 30.11.2012 17:35, schrieb Joe Taylor:
Hi Stefan
On 11/30/2012 11:00 AM, Stefan Schäfer wrote:
Hi Joe/K1JT,
A general question to the NB: What do you think about its performance in
the current state? Normally NB is disabled when starting the program.
Applying a NB to "remove" QRN makes a big effect on LF, you know.
Is there an estimation like 2 dB improvement or so?
So far I have spent very little time testing or optimizing the WSJT-X
noise blanker.
Here are some relevant examples from a week ago on 80 meters. The
same recorded raw data has been decoded twice using WSJT-X r2788.
Everything was the same for the two cases, except for switching NB OFF
or ON.
UTC Sync dB DT Freq Drift Message
-------------------------------------------------
2156 5 -26 0.3 1349. -1 K1JT G0MGM -09 (NB OFF)
2158 4 -25 0.2 1349. 0 K1JT G0MGM RRR (NB OFF)
2156 9 -22 0.3 1349. -1 K1JT G0MGM -09 (NB ON)
2158 4 -22 0.2 1349. 0 K1JT G0MGM RRR (NB ON)
2200 4 -22 0.1 1346. 1 K1JT I3VWK JN55 (NB OFF)
2200 5 -21 0.1 1346. 1 K1JT I3VWK JN55 (NB ON)
Although there's some suggestion that the present noise blanker can
improve S/N by 1 to 4 dB, this is hardly a definitive result.
If you have some useful example files with a marginal JT9 signal and
heavy QRN, please send them along! I may find some time to work on
the noise blanker soon.
-- 73, Joe, K1JT
PS: alas, I listened for your LF signal on 137.42 last night, but did
not copy anything.
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