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TV distribution amplifiers vs HDTV
- Thread starter b344077
- Start date
K
kyscott
Guest
As long as the DA does not distort the RF envelop you should be fine. The only way to see if it will work is to, well, see if it will work.
We're excited Channel 6 is going away for NCE stations BUT those with rf overload at their homes will still have overload of rf amplifiers.
The nice thing about the interference if you can call it that is that the viewers will not receive any stations that are affected or unable to overcome the overload.
An NCE used an stl signal (white noise) into their transmitter, accidentally, to keep any tv 6 complaints from being lodged. What a great idea. The Channel 6 got complaints of noise in their audio but were unable to diagnose the problem.
Viewers with overload including overload induced by preamps (any area within a few miles of a Class A) will see the effects well into the UHF spectrum.
Currently the CH 6 replacement here on Ch 20 something can't been seen within 20 miles of it's transmitter well. Those expecting to see network programs on directional antennas at 30 miles are out of luck. if you think everyone is using shielded cable there are 2 many sets still with twin lead. And when the local tv guy repalces the antenna and lead in wire with something better and it still doesn't work....
The nice thing about the interference if you can call it that is that the viewers will not receive any stations that are affected or unable to overcome the overload.
An NCE used an stl signal (white noise) into their transmitter, accidentally, to keep any tv 6 complaints from being lodged. What a great idea. The Channel 6 got complaints of noise in their audio but were unable to diagnose the problem.
Viewers with overload including overload induced by preamps (any area within a few miles of a Class A) will see the effects well into the UHF spectrum.
Currently the CH 6 replacement here on Ch 20 something can't been seen within 20 miles of it's transmitter well. Those expecting to see network programs on directional antennas at 30 miles are out of luck. if you think everyone is using shielded cable there are 2 many sets still with twin lead. And when the local tv guy repalces the antenna and lead in wire with something better and it still doesn't work....
The comment on distorting the RF envelope is right on. An analog signal will tolerate some RF overload within a preamp or distribution amp. HDTV is more critical. I've experimented at length on the subject of getting the best TV reception once you are no longer connected directly to the antenna. I haven't found the perfect answer. At 70 miles, I see WBKI-LP 28 from Louisville with 10% snow if I have a TV connected to the antenna directly. The best I've done once it's in the house (110' of 3/4 hardline & 100' of RG-6 later) is about 30% snow. It's a hit or miss proposition and I haven't found any cookie cutter solution except to look at the output of each active amplifier in the system & be certain that the input & output look identical, just with more amplitude.
That helps. My vacation place is in Union Pier, Mich. It's over 50 miles from Chicago (over Lake Michigan) and 30 miles from South Bend. I use two stacked antennas that Radio Shack lists a suburban grade. I do not use a pre-amp but get most Chicago stations like a local as well as most South Bend stations. It appears that I should have no problems.
K
kyscott
Guest
b344077 said:That helps. My vacation place is in Union Pier, Mich. It's over 50 miles from Chicago (over Lake Michigan) and 30 miles from South Bend. I use two stacked antennas that Radio Shack lists a suburban grade. I do not use a pre-amp but get most Chicago stations like a local as well as most South Bend stations. It appears that I should have no problems.
You may have different results with HDTV signals. I'm looking at the FCC database and some of the DTV stations are directional. You may have a small problem with WGN. They have a deep null to the east/northeast. WYCC has a null in the same direction. WCIU and WFLD have very, very sharp nulls in your direction. WTTV has a heart shaped pattern with the null to the northeast.
All this may be null and void next February depending on if the stations are going back to their NTSC channels for DTV broadcasting.
It's my guess but there are going to be many unhappy people as of Ferbruary, 2009.
Nearly everybody by now knows that HDTV is coming but the distribution amplifiers will have problems, the tv in the garage on rabbit ears will be a thing of the past and TV stations once recieved well may be gone forever.
Nearly everybody by now knows that HDTV is coming but the distribution amplifiers will have problems, the tv in the garage on rabbit ears will be a thing of the past and TV stations once recieved well may be gone forever.
K
kyscott
Guest
b344077 said:It's my guess but there are going to be many unhappy people as of Ferbruary, 2009.
Nearly everybody by now knows that HDTV is coming but the distribution amplifiers will have problems, the tv in the garage on rabbit ears will be a thing of the past and TV stations once recieved well may be gone forever.
It depends on how fast the stations put the HDTV signal on their current NTSC signal. Stations have a choice, most High V and UHF stations are keeping their current analog channel and moving the digital signal to it after the cut off date. Most current NTSC channels are non-directional. Moving back to that channel will afford a better overall signal. Low V stations will stay on their DTV assignments because propagation of digital signals below, say, 88MHz is not very favorable.
In Indy we have CH's 4, 6, 8, and 13. From Cincy we could get 9. Louisville 11.
I remember the cow my dad had when Wildcat basketball went to a not so high power CH 32 years ago. After their upgrade what happened? Wildcat basketball moved to 41.
This was evidence that UHF analog was not "hot" and the 30 foot tower with channel master antenna was not totally sufficient.
Bob's rf doesn't count. He lives on a mountain. I think he told me he can see the water tower at Greensburg from his deck. 30 miles?
The garage tv sets and kitchen tv sets are the ones that will gripe most. old people with soap operas and such.
The problem with us is the large number of analog channels here and the expectation of a snow free picture from a 100 kw v. Those days are soon to be gone.
I remember the cow my dad had when Wildcat basketball went to a not so high power CH 32 years ago. After their upgrade what happened? Wildcat basketball moved to 41.
This was evidence that UHF analog was not "hot" and the 30 foot tower with channel master antenna was not totally sufficient.
Bob's rf doesn't count. He lives on a mountain. I think he told me he can see the water tower at Greensburg from his deck. 30 miles?
The garage tv sets and kitchen tv sets are the ones that will gripe most. old people with soap operas and such.
The problem with us is the large number of analog channels here and the expectation of a snow free picture from a 100 kw v. Those days are soon to be gone.
Tom Wells said:If you have a summer home in Union Pier, it might be better to enjoy that and give up on TV in the summer. 8)
That's what my wife says but even when we're up there, I do enjoy an occasional Cubs game and watching the news.
The reason we don't have cable or DirecTV is that we seldom have the set on. When I was in College, I installed master antenna systems to make ends meet and so I still enjoy wiring a house for sound and TV (it's in my DNA). My wife thinks the place in Union Pier is overwired. Maybe.
We're two blocks from Lake Michigan so most nights when there is a good sunset, you can find us on the beach with two canvas folding chairs and a bottle of Michigan wine. Pure Michigan you know.
Back to Basics
I believe that the original question was whether an existing TV DA system would work with a digital signal. Since the signal is in the same frequency range, and a digital signal is actually simpler than an analog signal, it should work just fine. In fact, you may have a better amplified signal than you had with analog because less noise is likely to be added by the amp. Obviously, you'll need a DTV tuner on the receiving end.
Now you can have your discussion of how the range and/or quality of the originating signal may change under the new rules in February. It would seem that any station that reverts to their original frequency should come in with the same signal strength, while stations moving from the lower VHF frequencies may have very different coverage patterns depending on their new UHF allocation.
I believe that the original question was whether an existing TV DA system would work with a digital signal. Since the signal is in the same frequency range, and a digital signal is actually simpler than an analog signal, it should work just fine. In fact, you may have a better amplified signal than you had with analog because less noise is likely to be added by the amp. Obviously, you'll need a DTV tuner on the receiving end.
Now you can have your discussion of how the range and/or quality of the originating signal may change under the new rules in February. It would seem that any station that reverts to their original frequency should come in with the same signal strength, while stations moving from the lower VHF frequencies may have very different coverage patterns depending on their new UHF allocation.
The fly in the ointment is what lightning does to channel 2-6 & to a lesser degree, 7-13. EVERY disruption in an HDTV signal causes the picture to pixel out until it re-establishes a lock. Imagine watching channel 2 for severe weather info & every time lightning hits within 10 miles, you lose the signal for a couple seconds--channel 2 may have the world's best weather coverage, but if no one can see it, it's all for nothing. Place me on record as sayng that there will be virtually no HDTV signals on 2-6 five years from now. If everyone could have 1000000 (I'd prefer 5000000--what's wrong with actually improving coverage as part of this?) watts of non-directional UHF HD, this whole thing just might work pretty well.
What I've found a bit frustrating or disturbing is the sheer number of public viewers who are for some reason unfamiliar with what I call "REAL TV", over the air broadcasting. Recently I was in a consumer electronics retailer and speaking to one of the sales reps about DTV converters. His answer was they come in 10 or 20 at a time and sell out like hotcakes. He was amazed that that many people still used over the air reception.
Anyway, I'm about 20 miles SW of NYC and get 32 DTV channels easily, but not familiar with what reception in the further outlying areas is just yet.
Anyway, I'm about 20 miles SW of NYC and get 32 DTV channels easily, but not familiar with what reception in the further outlying areas is just yet.
My QTH is Owensboro, KY and almost all of our OTA come from Evansville, IN about 25 miles to the WNW. I am able to receive all of the HD channels except for WNIN PBS (DTV 12) due to the antenna. But the rest have solid signals except when a car goes by. The antenna is the gold double bowtie set top UHF antenna and an ancient 2002 HDTV receiver, actually it is a Direct TV receiver that was sold as a "HDTV" receiver. I have mentioned this elsewhere but the antenna used is the best passive UHF indoor antenna ever made, ironically after fifty years it's no longer made.
There might be confusion in this area between WTVW (Analog 7, Digital 28) and WEHT (Analog 25, Digital 59). WTVW will stay on Channel 28 but WEHT has paperwork to the FCC changing their digital allocation from Channel 59 to Channel 7. I can hear it now, "Why is it I have to tune to Channel 7 to watch Channel 25 and tune to Channel 28 to watch Channel 7?
There might be confusion in this area between WTVW (Analog 7, Digital 28) and WEHT (Analog 25, Digital 59). WTVW will stay on Channel 28 but WEHT has paperwork to the FCC changing their digital allocation from Channel 59 to Channel 7. I can hear it now, "Why is it I have to tune to Channel 7 to watch Channel 25 and tune to Channel 28 to watch Channel 7?
Keeping on topic these are what we specify for our projects.
http://www.rldrake.com/catv/DAseries.html
Blonder Tongue also makes low distortion amp.
http://www.blondertongue.com/
http://www.rldrake.com/catv/DAseries.html
Blonder Tongue also makes low distortion amp.
http://www.blondertongue.com/
radiorob2.0 said:There might be confusion in this area between WTVW (Analog 7, Digital 28) and WEHT (Analog 25, Digital 59). WTVW will stay on Channel 28 but WEHT has paperwork to the FCC changing their digital allocation from Channel 59 to Channel 7. I can hear it now, "Why is it I have to tune to Channel 7 to watch Channel 25 and tune to Channel 28 to watch Channel 7?
No viewer will ever know WEHT is on RF channel 7.
The station will transmit a signal that tells DTVs to tell their viewers that the station is channel 25. When the viewers do the autoscan, their TV will pick up that signal. And when the viewer punches in "25" on their remote, the TV will automatically tune to channel 7 and show WEHT. (if they punch in "07" on their remote, the TV will use the signal WTVW transmitted and will tune to channel 28 and show WTVW.)
Just one thing to add as the employee of a UHF station going to digital VHF. The station has always ran PSIP with the actual digital channel number.
The market has long been one of those with UHF stations close in, and VHF stations in the major cities.
We've had two problems. First, convincing the public that a UHF antenna will not receive VHF broadcasts too good, even with "boosters" on them. So even though they know were channel 8, they still do not understand the antenna difference.
And in the course of conversation I've discovered that the opposite works for the major metro VHF stations running digital UHF. People with the big yagis can't see the digital signal, so they "assume" that the station is not on the air, or just too weak to consider.
The second thing, the first wave of converter boxes are real garbage. I took a call from a guy, 8 miles from our TX, with a 4-element yagi pointed at us, and he gets breakup on his box. When we measured the signal on the coax, he has tons of usable signal. The box he got from Rat Shack has no sensitivity.
The market has long been one of those with UHF stations close in, and VHF stations in the major cities.
We've had two problems. First, convincing the public that a UHF antenna will not receive VHF broadcasts too good, even with "boosters" on them. So even though they know were channel 8, they still do not understand the antenna difference.
And in the course of conversation I've discovered that the opposite works for the major metro VHF stations running digital UHF. People with the big yagis can't see the digital signal, so they "assume" that the station is not on the air, or just too weak to consider.
The second thing, the first wave of converter boxes are real garbage. I took a call from a guy, 8 miles from our TX, with a 4-element yagi pointed at us, and he gets breakup on his box. When we measured the signal on the coax, he has tons of usable signal. The box he got from Rat Shack has no sensitivity.
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