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

[Lloyd Berg N9LB]

The RF frequencies have changed for Broadcast Television!

TV stations are mostly transmitting on UHF now.  This is to avoid 
lightning and other pulse interference that would otherwise shut down 
the digital signal stream if they would have stayed on their former "low 
band VHF" ( Ch 2 to 6 ) channels/frequencies.

WCCO, "Channel 4" is now transmitting on UHF CH 32 ( 578-584 MHz )
KSTP, "Channel 5" is now transmitting on UHF Channel 35 ( 596-602 MHz )

So, yes, propagation losses can now be quite high at times and very WX 
dependent as compared to the old analog VHF days.  Multi-path 
interference is also much worse on the UHF frequencies.

73

Lloyd - N9LB

On Thu, Jul 10, 2014 at 11:10 AM, Paul Husby wrote:

> Chris, I'm glad to hear that you have trouble too.  I'm only 4.5 miles 
> from the towers and also have a view of them in winter.  I just don't 
> understand why I can't get enough signal sometimes.  It hasn't always 
> seemed to correlate with wet/dry conditions, but now that I know it 
> isn't just me, I will pay closer attention.
>
> Ch4 always seems solid, Ch5 much more of a problem, as is Ch9 also. I 
> have wondered if it is significant that Ch4 has no subchannels, while 
> Ch5 has many?
>
> 73
> Paul W0UC
>
>
> On 7/10/2014 10:53 AM, Chris Elmquist wrote:
>>
>> On Thursday (07/10/2014 at 10:19AM -0500), Donn, WA2VOI wrote:
>>> No, the report doen't state "condition" of the foliage.  From
>>> contest, however, I assume it refers to "dry" foliage.  The report
>>> treats each source of loss seperately: i.e., atmospheric, water
>>> vapor, rain, scattering, etc.  (The report is aimed at mm wavelength
>>> propagation.  The foliage loss equation just happens to cover down
>>> to 200MHz.)
>> Got it.  Thanks.
>>
>>> FWIW, I agree with you completely re: rain-covered foliage and TV
>>> signals.  My "look" at the Shoreview towers is blocked by a hill and
>>> I suffer badly from multi-path.  Dry conditions are... OK, but
>>> during and after rain, no so much.
>> Pretty much the same experience here.  I used to be able to get a 
>> shock
>> off the coax when we had the analog TV transmitters running (well, 
>> OK,
>> not quite but it was a HUGE signal).   Now, I loose lock and go all
>> pixelated on KSTP and WCCO when it rains.  I am 7.5 mi from Shoreview
>> with no hills blocking, just trees.  I can see the aircraft beacon 
>> lights
>> on the towers from my roof when the leaves are not out.
>>
>>> PS The FCC report is readily available on the Internet.  (Where I
>>> got it originally.)  Don't rememebr exactly, but 'FCC OET Bulletin
>>> 70' in a search engine should find it.
>> OK. Thanks Donn.
>>
>> Chris N0JCF
>
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