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[WB9LUR]

Please, I don't use FT8 - fine if you do - just want to understand something. When I see a spot posted, frequently there appears to be a signal report of some sort. Is this a S/N for a specific bandwidth? What else do I need to know to interpret this into something useful to me - the op that wants to know what's open where? And, importantly, how does this correlate to RBN CW S/N?

Randy / WB9LUR

PS...please, no anti-FT8 vs FT8 is great arguments. This is a specific tech question.

[N6YWU]

WSJT-X reports FT8 SNR relative to a 2.5 kHz bandwidth, which is a typical bandwidth for an SSB receiver in USB mode.

However an FT8 transmission takes up only about 50 Hz, with each tone having a 6.25 Hz detection bandwidth.  So some say that the “real signal to noise ratio” is the value reported by WSJT-X (the value usually sent in FT8 replies and posted to spot reports), plus another 26 dB.

Figure 2 on this blog page https://kf6hi.net/radio/SNR.html shows a comparison between minimum FT8 SNR (with respect to a 2.5 kHz noise bandwidth), and that required for various types of CW QSOs.

[N4UFO]

Simple version... reports range from +26 to -24. If the report is '+', you can work'em on CW IMHO. If it's '-' then the higher the number, the weaker he'd be. I'd say -10 or less, would be tough and in the noise. Between 0 and -10, all depends.

And I'm a guy who's worked JA on 160m with 100w.  Only it was a weird kinda inverted L with a single counterpoise instead of a low dipole. (What is 'was' was luck! Sunrise spotlight. My ERP must have been in the milliwatts!) So maybe I am a little off, but likely not too far. Hope this helps.

73, Kevin N4UFO

[WB9LUR]

https://kf6hi.net/radio/SNR.html

Thanks for the link. Studying now.

Randy / WB9LUR

[K0UA]

Randy you should try WSPR some time. I would reccomend 40 meters at night and start at the 1 watt level which is +30 dbM. Set up your transmitter and run for a couple of hours. Go do something else while it is running as it is pretty boring. Of course you will print many other calls and there signal strength and their stated power levels. Then go to the WSPRnet.org site and see how everyone else in the world reported you.
It is pretty interesting what you little one watt signal will do worldwide on a good night. Of course 20 meters in the day is pretty cool too.

https://www.wsprnet.org/drupal/

Go to database (upper right corner)

fill out the form with you callsign, and band etc, and hit update at the bottom.

You will get an education.

[WB9LUR]

Simple version... reports range from +26 to -24. If the report is '+', you can work'em on CW IMHO. If it's '-' then the higher the number, the weaker he'd be. I'd say -10 or less, would be tough and in the noise. Between 0 and -10, all depends.

And I'm a guy who's worked JA on 160m with 100w.  Only it was a weird kinda inverted L with a single counterpoise instead of a low dipole. (What is 'was' was luck! Sunrise spotlight. My ERP must have been in the milliwatts!) So maybe I am a little off, but likely not too far. Hope this helps.

73, Kevin N4UFO

"reports range from +26 to -24. If the report is '+', you can work'em on CW IMHO"

Will test this for myself - good intel. Thanks.

"And I'm a guy who's worked JA on 160m with 100w.  Only it was a weird kinda inverted L with a single counterpoise instead of a low dipole. (What is 'was' was luck! Sunrise spotlight. My ERP must have been in the milliwatts!)"

Milliwatts? Yes, absolutely, luck is way powerful. As a DX'er will gladly accept all the luck I can get.

Randy / WB9LUR

[K0UA]

If you enjoyed the signal reports from all around the world with your 1 watt transmitter, try 100 milliwatts next which is  +20dbM.  How do you measure power levels that low you say?  Well if you have the QRPP wattmeter you can do it that way, OR, if you have a 7300 or other SDR radio you can use your built in scope's graticule to get close.  Start with a know power level like 100 watts (+50dbM) and note where it hits on the graticule's 10 db per division scale. Then reduce it to the next division, and on down until you get to 100 milliwatts as indicated on your scope. Use your WSJT-x power slider NOT the rigs rf power control. The pwr slider is calibrated by the mouse hover pop ups, but I trust the graticule on the radio more. Then you can try 10 milliwatts or even 1 milliwatt  (0 dbM) it is kinda fun. You will be very surprised on how far WSPR will carry you with flea power.

[WB9LUR]

Randy you should try WSPR some time. I would reccomend 40 meters at night and start at the 1 watt level which is +30 dbM. Set up your transmitter and run for a couple of hours. Go do something else while it is running as it is pretty boring. Of course you will print many other calls and there signal strength and their stated power levels. Then go to the WSPRnet.org site and see how everyone else in the world reported you.
It is pretty interesting what you little one watt signal will do worldwide on a good night. Of course 20 meters in the day is pretty cool too.

https://www.wsprnet.org/drupal/

Go to database (upper right corner)

fill out the form with you callsign, and band etc, and hit update at the bottom.

You will get an education.

I've always been intrigued by this WSPR thingy - but not really having a great understanding - will take a closer look. May have some dumb questions to ask.

Randy / WB9LUR

[K0UA]

And once you get your WSJT-x all installed and figured out for WSPR, and if for some reason you should want to try your hand actually making a contact, Well just change the mode pull down menu to FT8.     And you are good to go. 

[WB9LUR]

And once you get your WSJT-x all installed and figured out for WSPR, and if for some reason you should want to try your hand actually making a contact, Well just change the mode pull down menu to FT8.     And you are good to go. 

Thanks for the info, but I'm seeing this FT8 only as a possible propagation research aid in the way I use RBN and the spotting sites - lot's of custom filters for targeted results. Maybe I can use FT8 spots to my advantage-maybe not. I'm really a purist on my DXCC pursuits. Won't be making any QSO's on FT8 or any other digital mode. I'm going to do this my way.

Randy / WB9LUR

[K0UA]

Randy you should try WSPR some time. I would reccomend 40 meters at night and start at the 1 watt level which is +30 dbM. Set up your transmitter and run for a couple of hours. Go do something else while it is running as it is pretty boring. Of course you will print many other calls and there signal strength and their stated power levels. Then go to the WSPRnet.org site and see how everyone else in the world reported you.
It is pretty interesting what you little one watt signal will do worldwide on a good night. Of course 20 meters in the day is pretty cool too.

https://www.wsprnet.org/drupal/

Go to database (upper right corner)

fill out the form with you callsign, and band etc, and hit update at the bottom.

You will get an education.

I've always been intrigued by this WSPR thingy - but not really having a great understanding - will take a closer look. May have some dumb questions to ask.

Randy / WB9LUR

I would be happy to help you get it all set up and working. If you have a modern SDR radio, all you usually need is a USB A to USB B cable.  Probably have one of those laying around the house. If not, i can help you find an interface. Just send me an email and we can exchange phone numbers. I am retired, so any time is a good time.  73   James

[WB9LUR]

Randy you should try WSPR some time. I would reccomend 40 meters at night and start at the 1 watt level which is +30 dbM. Set up your transmitter and run for a couple of hours. Go do something else while it is running as it is pretty boring. Of course you will print many other calls and there signal strength and their stated power levels. Then go to the WSPRnet.org site and see how everyone else in the world reported you.
It is pretty interesting what you little one watt signal will do worldwide on a good night. Of course 20 meters in the day is pretty cool too.

https://www.wsprnet.org/drupal/

Go to database (upper right corner)

fill out the form with you callsign, and band etc, and hit update at the bottom.

You will get an education.

I've always been intrigued by this WSPR thingy - but not really having a great understanding - will take a closer look. May have some dumb questions to ask.

Randy / WB9LUR

I would be happy to help you get it all set up and working. If you have a modern SDR radio, all you usually need is a USB A to USB B cable.  Probably have one of those laying around the house. If not, i can help you find an interface. Just send me an email and we can exchange phone numbers. I am retired, so any time is a good time.  73   James

Your offer to help is very gracious. Thank you. Actually I don't own an SDR. So, why do I need one and if I really do need one - what is worthwhile and what is not - SDR wise? Told ya' - I'd have some dumb questions. Ha!

Randy / WB9LUR

[K0UA]

You don't have to have an SDR radio. I was just pointing out the ease of interfacing the more recent radios. But older radios can be interfaced to your PC also.  Lets just start, What radio do you have?

[WB9LUR]

You don't have to have an SDR radio. I was just pointing out the ease of interfacing the more recent radios. But older radios can be interfaced to your PC also.  Lets just start, What radio do you have?

A Kenwood TS-590 as primary. Alinco DX-SR8T transceiver backup - and some much older stuff in various states of operation and repair. If having an SDR makes this easier - why not?

 

[K0UA]

The 590 will be fine. And from what I can see, you will only need an USB AB cable. This should transfer both the audio and virtual serial data. I can research this a bit more if you are interested.