Quote:
Originally Posted by NN5I
I think that's one of the things that make the conversation interesting and fun. Sort of like a wandering bull session in a college dorm. But it sometimes drives the OP crazy with frustration. Whether I judge this as good or bad depends upon who the OP is.
It fustrates me that no one gave the OP a answer, or at least a good answer.
Is that true? All the countries I've heard of are terrestrial, and I had read somewhere that in some countries NTSC and PAL were still to be found.
But I can't claim really to know.
My question to you is - how many foreign - European countries are you going to drive your motorhome to? Yes there are different types of digital television, but for the most part what we have in Canada and the US is the same mode of broadcast.
Could be, for all I know. But it would surprise me to learn that UHF transmitters are so much less efficient than VHF transmitters.
Since you ask, I will explain it to you in my post. OK?
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About 8 years ago - I found myself needing a new hobby.
I got into DX television.
Yes I know to a truest ham Dx means out of country, but for practical purposes - lets call DX anything that is not normal reception.
In the analog days - the first broadcast networks ABC - formed from the NBC Blue Network, NBC, CBS - since they were the first on the block they had the pick of the best channels ( frequencies ) for broadcasting television.
Usually each network would have one VHF channel in each market - and the band plan specified that there was a one channel - ( guard channel) between channels.
Lets use Pittsburgh PA as an example - Pittsburgh started with WDTV - Dumont network.. Dumont had a 100% market share - this means that when you turned on your television - the only channel you could get before 1949 was channel 3 - WDTV. When you were done watching TV you shut it off! This was because Dumont was responsible for the coaxial cable that was strung through the coal fields of Pennsylvania and Pittsburgh was the golden spike that allowed broadcast television to go west beyond Pennsylvania.
Before that time, there was to separate places where most programming originated - New York City and Los Angeles California.
If a program was made in New York, they had to transfer it to a disc called a Kinescope and then transfer it back into a television camera and rebroadcast it. After that - Dumont gave each network a period of time when they could use his cable to transmit their programming and his stations could pick and choose which programs they desired to broadcast. So basically you could watch programs from each network on the Dumont network - it was the 7th largest market in the country.
As more and more television stations were put on the air, the bandwidth was taken up with the now 4 broadcast networks.
You see Westinghouse had their world headquarters in Turtle Creek PA and they didn't like it that they couldn't get a permit to build a television station in Pittsburgh, so they pressured the Dumont network to sell them their station in Pittsburgh.. To get the FCC to go along with it, they promised the FCC that they would share the channel with the college - what we now call Public Broadcasting - PBS.... KDKA later migrated to channel 2 and WQED PBS moved to channel 13 when the ban was lifted and people were allowed to build new television stations..
Coincidentally WPSU - Penn State University got channel 3 in State College, the transmitter was located in my backyard atop Rockton Mtn. near Clearfield PA.
The reason why no one wanted to be on UHF was because the Superheterodyne technology of the day did not work well on UHF and the televisions made before 1958 didn't even come with a UHF tuner - you had to use a converter box - much like what happened when we switched from analog to digital and we had all those analog televisions still in use.
A 15KW analog VHF signal atop a 1000' stick, atop a mountain, on channel 3 had a service contour area of about 120 miles - 65 miles in each direction - with no problems.
This allowed someone with a roof top antenna in Punxsutawney PA to watch television that originated in Pittsburgh, Johnstown and Altoona virtually at will, with nothing more then a good antenna rotor and a long range antenna.
3 markets with one antenna - in one location...
When the television stations went to migrate to digital, it was found that digital stations worked better on UHF then VHF.
UHF is like a flashlight, when you shine the beam north, it does not go south.
When you shine the light up, it does not come back down and shine on the ground, unless there is something in the clouds that is reflective.
When the signal travels through the atmosphere - unless there is something for it to reflect off of, it eventually just travels straight out into space.
VHF is like sound, if you stand on one side of a house and you yell real loud, the people on the other side of the house can hear you.
VHF goes up one hill and down the next.
But because it is a longer wavelength, it is more susceptible to noise.
" Remember now - we are HAMS! We are supposed to know this!"
Motor brush noise, ignition noise, fence charger noise, static discharges from lightning all disturbs reception.