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Re: [VHFcontesting] Digital modes vs. digital modes vs. CW etc.

To: John Santillo <u1004467@warwick.net>
Subject: Re: [VHFcontesting] Digital modes vs. digital modes vs. CW etc.
From: Mark Spencer <mark@alignedsolutions.com>
Date: Thu, 25 Jan 2018 15:00:11 -0800
List-post: <mailto:vhfcontesting@contesting.com>
If anyone in the PNW / Vancouver lower mainland area wants to try something 
along these lines let me know.

Based on my experiences over the last few years on a path from CN89 to CN94 on 
144 MHz I am reasonably confident that FT8 provides a useful improvement over 
SSB / CW but I don't really have any data to back that up.

Switching from CW to JT65c on a 1296 MHz path from CN89 to CN87 has left me 
with a similar impression re JT65c vs CW but again my data to support this 
impression is very limited.

Looking at the signal strength from  the pilot carrier of a DTV transmitter 
(just below the 222 MHz band) on a CN89 to CN87 path also leaves me with the 
impression that there is a lot of short term variation in signal strength and 
effects due aircraft scatter (and likely other effects) that would need to be 
taken into account if one wants to really understand the differences between 
various modes over real world VHF and up paths.

I'm contemplating taking another run at monitoring the DTV pilot carrier signal 
strength over the CN89 to CN87 path and trying to tie the results into to 
likely air craft scatter events.  Again if anyone wants to try and tie this 
into a field trial of various amateur VHF and up modes I'd be interested in 
having a chat.  

73
Mark S
VE7AFZ

mark@alignedsolutions.com
604 762 4099

> On Jan 24, 2018, at 5:37 PM, John Santillo <u1004467@warwick.net> wrote:
> 
> What I would like to see is a real field experiment using a variety of
> different digital modes over a known path and known distant over a short
> period of time.  A qualitative study pitting one digital mode against
> another and their performance vs. CW.  
> 
> I think digital modes are the future.  As the algorithms, forward error
> correction and software evolve so will the digital modulations.
> 
> 432 would be a good place to start.
> 
> 
> 73,
> 
> John
> N2HMM
> 
> 
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