22 Apr 2014

6m super DX

The evening of June 25th 2007 was a very memorable one here: K1TOL (Lefty) was worked on 6m QRP CW from the old QTH when I was using just 2.5W from the FT817 to my V2000 vertical fed by a long and lossy length of RG58 coax. ERP could not have been more than 1W. His big antenna certainly helped, but this was a great contact in the log. The mode was multi-hop Es.

K1TOL's 6m QSL card


Anonymous said...

I still think 'good ears' and c.w.
is better than wspr at weak sig stuff.
They used to say when psk came in that it could resolve sigs a human ear simply couldnt pick up under the noise. Actually that was hogwash.

Roger G3XBM said...

Tony, I think you will find WSPR is better. Nonetheless, CW in narrow bandwidths is pretty good.

David Tegerdine said...

WSPR signals at -28db SNR in a 2.5kHz bandwidth are completely inaudible, no matter how good your ears are. I know some don't like it, but digital signal processing thoroughly beats the brain for weak signal working.
David G0LRD

Anonymous said...

Hi Roger and David. Yes i agree with wspr. with the long time domain for reception.
But i did some tests wid psk and to put it simply it didnt live up to the way it was touted as a weak signal mode, often decoding was starting to become 'bitty' yet i could still plainly hear the psk audio suggesting cw would cut it as well.
I'm a wspr and cw fan btw.

David Tegerdine said...

Tony, I agree about PSK vs RTTY. PSK performs a little better I think, but this is often undone by the fact that PSK operators usually leave their passband wide open so they can simultaneously decode multiple QSOs. I don't know how we got on to PSK though - you started off claiming the human ear was better than WSPR - this I'm afraid doesn't stand up to any mathematical scrutiny. At the end of the day however, human or computer, it boils down to the information-rate vs. SNR trade-off. I bow to Mr Shannon & Mr Hartley !