[600MRG] WSQ - A Weak Signal QSO mode for LF/MF [-25dB snr]

[Neil Klagge]

Ahhh, yes, that worked. Tnx Brian. 

Sent from Neil's iPhone

> On Feb 11, 2015, at 07:23, Brian Pease <bpease2 at myfairpoint.net> wrote:
> 
> I forgot that there are capitol letters.  Try http://www.qsl.net/dl4yhf/WSQ/index.html
>> On 2/11/2015 10:18 AM, Neil Klagge wrote:
>> Brian, that link did not work. "Error 404, page not found"
>> 
>> Sent from Neil's iPhone
>> 
>>> On Feb 11, 2015, at 07:07, Brian Pease <bpease2 at myfairpoint.net> wrote:
>>> 
>>> I have done some bench testing of a WSQ2 link with real atmospheric noise bursts.  The mode really works down to its -25dB limit.  The best thing about it seems to be its ability to sync & re-sync quickly after a drop out.  Remarkable performance considering that it is not time-synced and has no forward error correction or fancy coding and does not require precise tuning or post processing. Being a 1 tone at a time FM mode, it is bothered by continuous tones within its receive bandwidth.  I recommend the "enhanced" version of WSQ2 by DL4YHF at qsl.net/dl4yhf/wsq which has a squelch setting, adjustable audio tones, a spectrum line during receive, AGC on/off, etc.
>>>> On 2/11/2015 6:48 AM, Ralph Wallio, W0RPK wrote:
>>>> http://www.qsl.net/zl1bpu/SOFT/WSQ.htm
>>>> 
>>>> Amateur Radio enthusiasts who are interested in the LF and MF bands will be familiar with WSPR. Used as a propagation probe or beacon, WSPR allows very weak signals to be detected, frequently as weak as -27dB SNR or lower. However, once you have established that a signal path exists, how then do you hold a QSO?
>>>> 
>>>> But what QSO mode matches WSPR for sensitivity?
>>>> 
>>>> WSPR is not a QSO mode, and is very slow, so you cast around for something else - to find that no 'chat' modes offer performance anywhere near the -27dB sensitivity of WSPR. Not Morse, PSK31 or even CMSK will reach this sensitivity. Even DominoEX4 will only manage about -18dB SNR. The best offering is JASON, with a sensitivity of about -25dB, but it is
>>>> 
>>>> V... E... R... Y...     S... L... O... W...
>>>> 
>>>> How frustrating!
>>>> 
>>>> So, Con ZL2AFP and Murray ZL1BPU decided to do something about this problem - to take on the challenge to design a QSO mode capable of sensitivity performance near that of WSPR, and much faster than JASON: fast enough to allow real QSOs. To do this required a completely new approach. Using a new IFK design with more tones, plus text compression techniques, we have achieved not quite a comfortable 'chat' speed, but at least enough typing speed to allow contact and to exchange information within a few minutes. Novice CW operators have been doing much the same for decades (although not at -25dB SNR!).
>>>> 
>>>> 
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