[NLRS] Is there published data on tree foliage ...

[Dr. Gerald N. Johnson]

On 7/11/2014 7:09 AM, Jon Platt via NLRS wrote:
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> I just don't understand why I can't get enough signal sometimes.
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> I suspect multi-path.  I don't have a deep understanding of the new
> digital TV format but I suspect that the TV receiver might be having
> a hard time determining which time varied signal to sync with?
> Although I live farther from the Shoreview I see it too.
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> Newer TV sets have a build in signal monitor (S-meter) that you can
> find in the TV's menu structure and when I watch mine I have a signal
> level of 97/100 or 98/100 and the meter is in the "green", then
> suddenly the picture drops and the signal reading goes to 0/100
> before the TV "relocks" and the picture appears again.
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> I think the new digital TV format is designed to be sent over a cable
> and not propagated via the ether?  Maybe a sharper antenna would help
> .... it may depend on where the strongest multipath reflectors are
> coming from?

There have been those who alleged that the ATSC choice was poor compared 
to DVB that most of the world outside the USA chose for digital TV.

ATSC does use the entire 6 MHz channel for digital data and its packed 
because there can be half a dozen 480I in the same spectrum that analog 
used about 5 MHz per channel. There is a carrier at one place in the 
channel, but otherwise it sounds like white noise with a uniform 
intensity except for a few quiet kHz at each channel edge on a narrow 
band receiver.

More directivity should come with higher gain to get more signal to work 
with and less multipath.

All stations transmit that carrier at the same exact offset from the 
channel lower edge, so there's no longer the information based on 
frequency to identify a station with a narrow band receiver to learn 
about propagation details and band openings.
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> 73, Jon W0ZQ
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> Register for the CSVHFS conference on July 25-26th at:
> http://www.csvhfs.org/2014conference/index.html
>
73. Jerry, K0CQ