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Discussion Starter · #1 ·
Hello

What did a -85 dbm signal look like on NTSC on RF channel 68 in a location with near atmospheric noise and a ntsc station on channel 67 with a signal power of -60-65 dbm with a sensitive tv like a sony kv-27exr10.

The sony tv was really good at getting audio where the picture was covered in snow.
 

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Hello

What did a -85 dbm signal look like on NTSC on RF channel 68 in a location with near atmospheric noise and a ntsc station on channel 67 with a signal power of -60-65 dbm with a sensitive tv like a sony kv-27exr10.

The sony tv was really good at getting audio where the picture was covered in snow.
My guess is it looked something like this:

NTSC Adjacent Channels 67-68.jpg


Some energy from the stronger channel 67 was spilling into channel 68, making it more difficult to receive channel 68.

Also, channel 68 probably didn't have sufficient C/N for the video carrier, but there was sufficient SNR for the channel 68 audio which is FM that resists noise.

But we no longer have NTSC Analog TV transmitters on those RF channels.
 

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Discussion Starter · #3 ·
My guess is it looked something like this:

View attachment 3128874

Some energy from the stronger channel 67 was spilling into channel 68, making it more difficult to receive channel 68.

Also, channel 68 probably didn't have sufficient C/N for the video carrier, but there was sufficient SNR for the channel 68 audio which is FM that resists noise.
What does it look like when channel 68 has no adjacent channel and channel 53 is vacant. Does it matter that channel 83 has a cell signal from 2-3 miles away?
 

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What does it look like when channel 68 has no adjacent channel and channel 53 is vacant. Does it matter that channel 83 has a cell signal from 2-3 miles away?
I don't understand your question. There are no longer any NTSC Analog channels on 58 and 83. We now only have ATSC Digital channels, and none of those are above RF channel 36.

Are you talking about virtual antenna channels or cable channels?

A channel that is only -85 dBm is extremely weak, almost at dropout.

Is this your report from the Cleveland thread?
RabbitEars.Info
 

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Discussion Starter · #5 ·
The topic of my question refers to how NTSC stations with weak signal strengths. display on NTSC TVs with low noise figures. In my follow up question I attempt to figure out what a channel 68 would look like on an analog tv with no co-channel stations and no taboo stations 15 channels apart. In this case I also ask whether a cell tower signal on channel 83 could impact a channel 68 as I believe a taboo channel 15 channels away could impact reception if the signals are within a few miles of the receiver

This is actually based on a real life scenario. In 2006-2008, I got WMFD on channel 68 with a channel 67 that was about 25 miles away (WOAC). Out of three different TVs only one tv gave audio that I could hear and lots of snow on the video.
 

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I'm closing this. This is an HDTV section and NTSC is not HDTV. What you received a decade ago is no longer relevant thanks to the sunset of analog television and US stations above channel 36 due to the repack.
 
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