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-   -   Why is ATSC on VHF so damn finicky? (http://www.videokarma.org/showthread.php?t=269707)

DavGoodlin 04-30-2021 03:54 PM

Quote:

Originally Posted by nasadowsk (Post 3233252)
As n aside, in the NTSC days, was UHF ever NOT finicky? I don't ever recall being able to get UHF decently..

I can answer this one as a DX'er, NO - As a supplement to fill in areas not able to have a VHF local channel, UHF was always meant for a 40 mile radius using a common roof antenna.

If you were clear up to 100 miles away or stuck in the woods 50 miles away, the Channel Master Parascope (4251) was the antenna you needed, to get any stable UHF and almost always with antenna-mounted preamplifiers.

At least analog was giving us clues if it was multipath OR weak signal screwing with finicky UHF:thumbsdn:

pgnl 04-30-2021 05:05 PM

Quote:

Originally Posted by DavGoodlin (Post 3233402)
I can answer this one as a DX'er, NO - As a supplement to fill in areas not able to have a VHF local channel, UHF was always meant for a 40 mile radius using a common roof antenna.

If you were clear up to 100 miles away or stuck in the woods 50 miles away, the Channel Master Parascope (4251) was the antenna you needed, to get any stable UHF and almost always with antenna-mounted preamplifiers.

At least analog was giving us clues if it was multipath OR weak signal screwing with finicky UHF:thumbsdn:

I just searched for that and have never seen anything quite like it in the UK. I suspect you would have needed planning permission from your local council to use it! its massive….

The UK has been UHF only since Colour TV started in 1969 (vhf was 405 line b&w ended 1985). When we had analogue TV the main transmitters power was usually 1000kw per channel - any type of aerial/antenna for 100 miles even with a mast top amp sounds like a stretch here… i am sure others will correct me though…

old_tv_nut 04-30-2021 05:09 PM

Quote:

Originally Posted by DavGoodlin (Post 3233402)
At least analog was giving us clues if it was multipath OR weak signal screwing with finicky UHF:thumbsdn:

RCA even put out a ghost ruler that you could hold up against the screen to estimate the delay and difference in path length, to take a guess at what object was causing the ghost.

In studying the ghost conditions for digital, we had special receivers that could plot the ghost signals from the equalizer taps. Then you could draw an ellipse on a map representing all locations that would produce that delay. This is how we discovered that the Golden Gate Bridge in San Francisco caused trouble in certain locations that had a simultaneous clear view of it and the transmitter.

https://live.staticflickr.com/65535/...e6c26bcb_z.jpg

https://live.staticflickr.com/65535/...522eb6b2_z.jpg

centralradio 05-02-2021 05:52 PM

Update .One transmitter is only 15- 20 miles from here.. Its still rubbish here.Crank up their power.Maybe it will reach me..


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