TV Fool  

Go Back   TV Fool > Over The Air Services > Help With Reception

Notices

Reply
 
Thread Tools
Old 10-May-2019, 3:40 AM   #21
rabbit73
Retired A/V Tech
 
Join Date: Aug 2012
Location: S.E. VA
Posts: 2,550
Quote:
Originally Posted by OTAFAN View Post
So, if I'm reading your chart correctly rabbit73, obviously you can have a higher noise floor on VHF low particularly, and still receive a watchable signal than either VHF high or UHF? And almost the opposite for UHF?
You almost have it right. Since the noise level IS higher on VHF, you must have a stronger signal on VHF than UHF to have an SNR of at least 15 dB above the noise.

One of the problems with VHF-Low reception of digital TV signals is that the FCC didn't allow enough extra transmitter power to overcome the higher noise level for reliable reception.
Quote:
Forgive my learning curve rabbit73. When I became a shortwave enthusiast years ago, the first thing I learned was as long as I get above the noise floor with my receiver, antenna setup etc., I could "catch" the signal I was looking for. And the quieter my noise floor the better for weak signal reception.

I presume similar for TV viewing? Thanks!
That is correct.
__________________
If you can not measure it, you can not improve it.
Lord Kelvin, 1883
http://www.megalithia.com/elect/aeri...ttpoorman.html

Last edited by rabbit73; 10-May-2019 at 3:49 AM.
rabbit73 is offline   Reply With Quote
Old 10-May-2019, 3:52 AM   #22
OTAFAN
Senior Member
 
Join Date: Apr 2015
Posts: 190
Ok, my learning curve just improved.

I really enjoy your classroom, rabbit73! Your postings on this forum truly enhance it!

All the best.....
OTAFAN is offline   Reply With Quote
Old 10-May-2019, 3:54 PM   #23
Nascarken
Banned
 
Join Date: Jun 2016
Posts: 346
Cool

Quote:
Originally Posted by rabbit73 View Post
You almost have it right. Since the noise level IS higher on VHF, you must have a stronger signal on VHF than UHF to have an SNR of at least 15 dB above the noise.

One of the problems with VHF-Low reception of digital TV signals is that the FCC didn't allow enough extra transmitter power to overcome the higher noise level for reliable reception.
That is correct.
I think the Fcc will up the power limitations but lets see how
We'll the new equipment perform 's first ?
And yes SCHOOL is in sessions when Ribbit Ears suggest
On tv broadcasting RF .And even one is paying close attention.
We'll thank you Rabbit ears for all of your hard work and dedication.
We'll everyone happy mother's day!!!
Nascarken is offline   Reply With Quote
Old 10-May-2019, 6:28 PM   #24
rabbit73
Retired A/V Tech
 
Join Date: Aug 2012
Location: S.E. VA
Posts: 2,550
Quote:
Originally Posted by OTAFAN View Post
Ok, my learning curve just improved.

I really enjoy your classroom, rabbit73! Your postings on this forum truly enhance it!

All the best.....
Thank you for your kind words. I keep learning, and I try to pass it on.

A good example of noise interference on VHF-Low is the problem Johnsonbrits is having with being able to receive channel 3:
Winegard HD8200U VHF question
https://forum.tvfool.com/showthread.php?t=16590

First he had to make sure the station was on the air, and then he had to track down the source of noise. At this point, he hasn't completely solved the problem, but he is working on it.
__________________
If you can not measure it, you can not improve it.
Lord Kelvin, 1883
http://www.megalithia.com/elect/aeri...ttpoorman.html

Last edited by rabbit73; 10-May-2019 at 6:56 PM.
rabbit73 is offline   Reply With Quote
Reply

Bookmarks

Tags
clearstream 4, denver, missing channels

Go Back   TV Fool > Over The Air Services > Help With Reception


Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off




All times are GMT. The time now is 8:55 PM.


Powered by vBulletin® Version 3.8.8
Copyright ©2000 - 2019, vBulletin Solutions, Inc.
Copyright © TV Fool, LLC