QRSS activity - slow down, you move too fast

Claude Elwood Shannon found out, that the required signal-to-noise ration (SNR) is proportional to the bit rate that can be achieved.
The better the SNR, the higher the achievable data rate.

But you can get to the other extreme as well:
The lower the data rate, the worse SNR you can tolerate.

QRSS does exactly that:
You slow down Morse code (lets say to a dot length of 30 s) and you may wonder how far you can get.

Such slow signals are hard to decode in the audio domain, so they are made visible with the aid of a PC.
The Spectran software by Alberto, I2PHD, and Vittorio, IK2CZL may be used as a good starting point.
There are plenty of other tools, but Spectran runs reliably on a low speed PC (Celeron 2.4 GHz) with multiple soundcards.

But keep in mind: The decoding itself is still up to the human user.

The following was sent to me by Peter, ZL2IK, to proof the reception of my signal.



Several operators make their monitoring available on-line, this is called a grabber.
KCTKS, N2NXZ and W4HBK may be stated as an example.


Important remark regarding operation:

A crucial point to QRSS operation is a very high frequency accuracy on both RX and TX side.
You should keep drift down to less than 100 Hz over one hour.

My current setup is a professional Rohde&Schwarz SMIQ signal generator:


It features an accuray of +/- 3 Hz if stand-alone, and can be synchronized to GPS, if required.
The antenna is again a vertical whip.
Due to the bad 10 m conditions so far, its output is amplified by 40 dB using a linear amplifier.
With that I can achieve up to 10 W of RF output (for the above image I used 4 W)

See an overview of the setups that I have evaluated so far.


As part of my Manned-Experimental-Propagation-Tests (MEPT)  I operate a QRSS beacon mostly on 28.000750 MHz.

Other centers of activity on 10 m may be around 28.221530 MHz (Chris, KCTKS, has initiated a small circle of interested hams who put their signal around there) and 28.322000 MHz (mostly frequented by Italian fellows).

Mileage highscore:


Band used power (equivalent isotropically radiated power) mileage in km per Watts EIRP
10 m / 28 MHz 4 W EIRP 4537 km / W EIRP  (tnx ZL2IK !)

Reception reports, received so far:

OC







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