[NLRS] PSK31 on 2m SSB

[Baker, Donn B]

Several years ago, W0LCP and I ran a few experiments on 2m and 432 w/PSK31.  Not a great distance, only about 30 miles.  We ran "low power", 10w or so, at each end. I'm running a 13 el CC on 2m and a modified CC417 on 432 (trigon removed)  Each has about 60 feet of 9913 coax on it.  Don't know Bud's station has for antennas.  We can work each other FB on 2m.  Once in a while on 432, its difficult.  Power at each end helps.

We ran PSK31 with no trouble on 2m.  Solid copy.  We finally got around to doing 432, and it, too worked with no problem.  Until....  Second or third night we worked on 432, copy was terrible!  No better than 20-30%.  It would come and go.  Eventually, I noticed "patterns" in my reception of Bud's signal. In the waterfall, the signal strength would go up and down.  FINALLY, I also heard airplanes overhead.  With no airplane noise, good, solid copy.  WITH airplanes in the area, no copy to (at best) poor copy.  Multipath off the airplanes

We didn't switch to 2m and try... didn't think of it.  Most likely there were similar results there, but maybe not as pronounced.

Maybe Bud has better recollection (records ?) than I do.  Bud ?

73 Donn
WA2VOI/0
> -----Original Message-----
> From: nlrs-bounces at mailman.qth.net
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> Sent: Monday, August 29, 2005 11:45 AM
> To: Northern Lights Radio Socie
> Subject: Re: [NLRS] PSK31 on 2m SSB
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> 
> Andrew T. Flowers, K0SM wrote:
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> >
> > There's an issue with PSK at VHF that many folks from HF experience 
> > don't consider.  Starting around 2m you'll find that multipath 
> > propagation causes phase distortions well beyond the 31.25 Hz 
> > bandwidth of PSK31.  This is simply because the scattering 
> media are a 
> > significant percentage of the wavelength in terms of their physical 
> > size.  
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> > Andy K0SM/2
> 
>