ATSC-OTA only??? Are there any TVs that can receive ATSC but not NTSC? My TV will do both but has seperate RF connections for either the ATSC or NTSC tuners...so tuning to the one channel not in ATSC (ie TVO) involves moving/reaching around the back of my set, unscrewing the antenna F-connector from the digital and connecting it to the analog, and back to the digital connector when I'm done.

End Result: I dont watch TVO. WNED is where my eyeballs, and support go.

Sure, I could use a splitter (potential loss of signal - I really dont understand splitter loss issues) or maybe an A/B switch, but it seems like a lot of hassle to use a technology (ntsc tuner) that I've long abandoned.

Barrie CKVR A-Channel is barely recievable where I am, even with a VHF antenna - that said, I never tried very hard either.

A splitter with a very short cable has essentially zero effect on digital signal "strength" (a tuner is more focused on SNR than absolute strength of the channel)
With NTSC, things get fuzzier with half the signal strength, though.

I've found that a splitter when used right at the TV's input has very little loss. I use a double splitter [2 splitters] harness set-up to send the downlead signal to both my converter input and the TV's RF input simultaniously.

Splitters are usually somewhat directional in their behavior, so if you set them up in the correct configuration you can avoid backfeeding the downlead signal into the converter boxes output.

connect the antenna downlead to <splitter 'A' input>
then use <splitter 'A' output 1> to the atsc box input,
then jump <splitter 'A' output 2> to <splitter 'B' output 1>,
then connect the atsc box output to <splitter 'B' input>
then <splitter 'B' output 2> goes to the TV's cable input.

When you get these connected, you can tune your TV to channel 3 for the atsc box to watch the digital stations, otherwise you can simply use your TV's ntsc tuner for all of the other analog stations.

___________________________________

As far as TVO digital. I believe they will shut down their analog transmitter sometime in August 2011 and then they will have to remove the analog antenna and then install the digital antenna. So a flash cut will not be happening instantaniously, but rather a week or two will lapse allowing time for the work to be done and tested. I'm sure that August's weather will not cause any delays in the changeover.

A splitter will always produce some loss. A 2 way split means each port gets only half the signal or 3 dB loss on each port. There's no way around that, other than adding an amp.

Half the signal strength (i.e. amplitude)
As I said, your ATSC tuner only cares about the ratio of good to bad 1's and 0's
As long as it's "loud" enough to still detect a 1 or a zero, it gets the same signal lock.
A similar analogy would be house electrical wiring.
As long as an outlet has the correct nominal 120v, a device with very low power draw (e.g 1.2W) will still run. It only becomes an issue when that 120v is spread over so many devices that the device can no longer get its 0.01A. Your splitter isn't making 2x 60v lines, it's making two 120v lines with half the available amps.
Or in the case of antenna systems, when there's a long run of cable at the end adding double the noise than would otherwise be there if you didn't split.
For very short runs, you're essentially producing two streams of equal quality, just less absolute strength/volume/amplitude/whatever you want to call it.

Ummm...

Re: amplitude

I think you'll find the important factor is signal/noise ratio and part of the noise comes from the receiver front end. This means that (with digital signals) you could have a clear picture, but lose it when using a splitter, as the S/N ratio is no longer sufficient, if your signal level is low enough. Also, amplitude generally refers to voltage, not power, which is proportional to the square of voltage. This means the voltage output of the splitter is about 70% of the input voltage, but the power out is 1/2 in (assuming a 2 port splitter, with - 3 dB output per port). As for cables, take a look at the specifications to see how much loss is involved (it also depends on frequency) for a length of cable. With RG-6 cable, the loss for 100' is 1.5 dB @ 55 MHz and 6.5 dB @ 1 GHz. So, even at 1 GHz, you'd need 50' to equal the loss through a 2 port splitter. Have you got any patch cables that long? BTW, that 6.5 dB loss is about what you'd get in a 4 port splitter or passing through 2 2 port splitters.


BTW, I studied Electrical Engineering at Ryerson, specializing in telecommunications systems. I also have decades of experience working with telecom gear.

I know what you're saying.
But the SNR is constant when you split.
You have one stream coming in.
Let's say it's 20 SNR.
20 good packets to 1 bad one.
If I take that same stream, the SNR remains constant, it's just that the signal is duplicated in both directions
Both are getting the same signal, just a little bit weaker.
Output 1 is getting 20 good packets to 1 bad one--it's not getting 10 good to 1 bad.
For the splitter to have any real "damage" to the signal, it would have to be of horrible quality or be connected to long leads. If you split and then have two long runs, you're essentially giving yourself double the noise added than if you'd kept the original signal.
But since you're splitting right at the device and using short (say, 1ft) cables, this is essentially nil

I know, I've done it.
My computer right now has two tuners running off of one line with 1ft cables.
If i connect the original cable to one tuner and check levels, the SNR is identical (measured by the tuner software) to that of when I run it through the splitter. (Yes, even for borderline stations)

Actually, the S/N ratio will always be worse, when ever you do anything. There's noise in the cables & splitter and the receiver noise figure doesn't change when you go through a splitter. By running the signal through a 2 port splitter, you'll be bringing the signal 3.5 dB closer to the noise floor of the receiver. If you were already on the edge of reception, then you'll now fall off.

Does anyone have any experience with one of these? At the Save and Replay site it says when using this joiner coupler you don't have to be concerned about the relative position or distance between two antenna's pointed in different directions. This sounds too good to be true.

Actually, the S/N ratio will always be worse, when ever you do anything. There's noise in the cables & splitter and the receiver noise figure doesn't change when you go through a splitter. By running the signal through a 2 port splitter, you'll be bringing the signal 3.5 dB closer to the noise floor of the receiver. If you were already on the edge of reception, then you'll now fall off.
I know what you're saying and I understand the theory.
But in practice it isn't so. Or at least the noise added to the system by the splitter is so low that it's essentially none compared to atmospheric variation that happens in 15s.. in other word's you'd be SOL anyway.

You're not only halving the "good" signal, but also the bad
The ratio to each output remains the same, plus whatever noise the splitter (and 1ft cable) adds.
In my experience, that added noise is negligible on reception, even on my borderline stations (i.e. MyTV 49)

Does anyone have any experience with one of these? At the Save and Replay site it says when using this joiner coupler you don't have to be concerned about the relative position or distance between two antenna's pointed in different directions. This sounds too good to be true.
It is simply a 2:1 splitter/joiner, like the kind you can find in dollar stores. But more expensive.

And yes, coupling two antennas in that fashion can often result in ghosting. Sometimes it gives good results for some channels though, so give it a try. But get the dollar store splitter, not that overpriced thing.

:)

mlord, here is a link to the Save and Replay site where they make this claim. It sounds to me like they are saying it will eliminate the ghosting problem by choosing the antenna with the best signal strength for whatever channel you have selected.

http://overtheair.saveandreplay.com/Antenna_Stacking_Ganging.asp

It's at the bottom of the page.
What are your thoughts?

An OTA setup is non-interactive, so the joiner would have no way of knowing what channel the TV was currently trying to receive, or what the signal level was. For the device to be able to compare antenna, it would have to have it's own built in tuner, and signal meter.

As I understand it, the problem with joining antenna together is that the incoming signal splits at the join. Half goes to the downlead, and the other half gets rebroadcast out the other receiving antenna. Would it be possible to have a joiner, where the inputs were each run through a high-speed diode?

This would prevent signal from being lost to a rebroadcast, as the only available path would be down the main lead. I'm assuming that the inherent voltage drop across even a germanium diode (300mV), makes this unviable.

If such a possibility does exist, that winegard product can't using it, as the manual says it can be used as a splitter or joiner. Diodes would make it one way only.

mlord, here is a link to the Save and Replay site where they make this claim. It sounds to me like they are saying it will eliminate the ghosting problem by choosing the antenna with the best signal strength for whatever channel you have selected.

Save and Replay are wrong. Even Winegard say it "is just like a 2-way splitter hooked up in reverse." See CC-7870 - Cross talk (http://winegard.com/kbase/kb_tip_results.php?tip_num=291).

mlord, here is a link to the Save and Replay site where they make this claim. It sounds to me like they are saying it will eliminate the ghosting problem by choosing the antenna with the best signal strength for whatever channel you have selected.
Bull-pucky. And very unethical marketing.
I don't think I would spend a dime at a place which so blatently lies about what a 50cent splitter really does.

Use your little grey cells, dude. How the heck can this device possibly know what channel(s) you are currently watching? It has no control inputs. Duh.

Cheers

Thanks mlord and Roger1818, that's what I thought.
That being said, why would Winegard be selling such an expensive splitter?
Does it have some sort of benefit ?

Thanks mlord and Roger1818, that's what I thought.
That being said, why would Winegard be selling such an expensive splitter?
Does it have some sort of benefit ?
Ask them, if you need to know.

Most likely, though, it helps boost their profits. :)
Just like "accessories" when purchasing a new car.

Now mind you, it probably includes a mast-mount (U-bolt), and some kind of rudimentary weather shielding. All of that might be worth an extra $5 to some people.

Cheers

Ask them, if you need to know.

Most likely, though, it helps boost their profits. :)
Just like "accessories" when purchasing a new car.

Now mind you, it probably includes a mast-mount (U-bolt), and some kind of rudimentary weather shielding. All of that might be worth an extra $5 to some people.

Cheers
I share your skepticism mlord, thanks.

I just looked at the Winegard ad and it just appears to be a normal splitter, used to combine two antennas, as has been done for many years. I don't know how it can eliminate multipath though. The 2nd antenna could be looking right at a reflection.

Here (http://www.winegarddirect.com/viewitem.asp?d=Winegard-CC-7870-2Way-Antenna-Joiner-Coupler-(CC7870)&p=CC7870)

That link from the manufacturer makes only sensible claims. The assumption there, is two identical antennas, pointed in identical directions, fed with identical coax leads. Like I do here, but with a $2 splitter in reverse. :)

Cheers