14 Jan 2015

Various modes compared

Comparisons were recently posted on the RSGB LF reflector. I am sorry but I cannot recall the author, although I think it was by a Dutch station.  Basically it showed (using 2500Hz bandwidth) that WSPR2 (2 minute WSPR) is some 29dB better than SSB and 12wpm CW some 15dB better than SSB. Of course there are all sorts of provisos and caveats, but it goes to show why WSPR is so very good with very weak signals although only basic data is usually exchanged with WSPR.

9 comments:

Steve McDonald said...

"although only basic data is usually exchanged with WSPR"

Roger ... This is what I find is the main weakness of WSPR as, in reality, no information is "exchanged" via radio! Like several of the newer digital modes, without the internet uploading, one has no idea of who is hearing your signal. Digging ever deeply into the noise floor for a signal is nice but to what end? They can never be used in QSO mode, even WSPR. I'd get really excited about some of these including WSPR if I could really "exchange" information with the other station, via radio! Help me see the light :-)

David (G0LRD) said...

Steve,
I hope Roger won't mind me offering you a response. There are several QSO-capable modes from the same stable as WSPR. On HF these are JT65 and JT9, which both use a 46 second 'over'.

JT9 offers almost the same sensitivity as the WSPR protocol. However, the QSOs are not truly free text, but instead use a fixed format exchange sequence taking 6 minutes in total.

73 David G0LRD

Roger G3XBM said...

Thank you David. I find WSPR brilliant as it providedld excellent feedback on propagation or of comparing antennas. What is so wrong with providing others with reports via the Internet? Like QSL cards but nearly instant.

Steve McDonald said...

Thanks Roger & David. I have enjoyed using JT65 on 2m EME over the years as well as FSK441 on m/s.

Roger , I don't think there is anything 'wrong' with providing reports of WSPR reception via the internet but, call me old fashioned, it is not an exchange of information via radio and for me, that somehow removes that natural "wireless link" radio-connection that is never a 'for sure" thing. We are probably comparing apples to oranges when comparing two-way digital modes like those David has mentioned, and WSPR, which will always be a beacon-only mode.

Steve VE7SL

Paul Stam said...

"although only basic data is usually exchanged with WSPR"

A lot of SSB stations only give 59, not even their name. And a lot of so called information with rag chew is crap.

73 Paul PC4T

Dick said...

I have my own view of certain digital modes. When a signal cannot be heard via those two appendages on either side of our heads, well, it seems to be less than ear-to-ear communications. Even My respectful opinion only.

I remember operating RTTY and radio-fax in the USAF during the late 1950's. I will grant the chug-chug RTTY and chirp-chirp radio fax modes were great fun.

Roger G3XBM said...

I use WSPR for 1-way beaconing and JT65 and JT9-1 for 2-way mainly. I use FM and SSB infrequently because my voice is still poor because of my stroke in September 2013. CW is also used from time to time as is PSK31. Each mode has its place. WSPR works at very low levels remarkably and the internet is only used to give the other station feedback quickly. You CAN use WSPR without the internet if you so choose. You get callsign, power and location so can see how well a station is doing, but the internet allows you to give the other station near instant feedback.

David Cope said...

I'm sorry, as much as I try, I find WSPR and other "human invisible" modes of little interest. As is the "59 QSL?" nonsense that passes for "communication" on voice.

Agree with Dick - RTTY, FAX - audible signals with "musicality".

Without an internet connection how does one verify a false positive in WSPR?

Roger - hope all well with you and your recovery.

73 David.

Paul Stam said...

Ham Radio also has something to do with technical experiments. When we do not adept to new technical progress we will fail as ham radio. Why stick to old modes, why not accept the new digital era? It's here and now. We can deny it, but why should we?