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

[Chris Elmquist]

On Friday (07/11/2014 at 08:27AM -0500), Mike King - KM0T wrote:
> 
> 
> I don't know how those analog "anti-ghost" things worked - guess I never
> thought about it.  But perhaps you guys in the cities need a "digital"
> version of it for the new TV format??

well, I have that with a DiSH Network satellite receiver :-)

But I'm with you guys that multi-path is the likely culprit. I see the
same behavior with the receiver(s) "s-meter", where I have nearly 100%
signal strength and then a few seconds later it all goes to zero.

One of my receivers (an HDHomeRunner network streaming box) along with
an app on Mac called "EyeTV" also reports "signal quality" in addition
to signal strength.  This number is typically 60 to 70% on the affected
channels. I don't know what is used to determine this "quality" but
if bit error rate is included, this would line up well with multi-path
problems messing up the datastream.

My current antenna is a dual-bay "bow-tie" in the attic, oriented normally
(ie, horz polarization).  I have seen some improvement when I connect
the TV feed to my discone (also in the attic) which is, of course,
vertically polarized.

Maybe I need circular polarization :-)

Chris N0JCF
 
> -----Original Message-----
> From: NLRS [mailto:nlrs-bounces at mailman.qth.net] On Behalf Of Jon Platt via
> NLRS
> Sent: Friday, July 11, 2014 8:10 AM
> To: nlrs at mailman.qth.net
> Subject: Re: [NLRS] Is there published data on tree foliage ...
> 
> I just don't understand why I can't get enough signal sometimes. 
> 
>  
> 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.  
> 
> 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.
> 
> 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?
> 
> 73, Jon
> W0ZQ  
>  
>  
> 
> 
> 
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-- 
Chris Elmquist