: ON - Ottawa, Vanier, Gloucester, Orleans - OTA
2011-04-07, 12:26 PM
Regarding Global, we will have to wait and see, but here are the issues:
Low ERP (and HAAT) for Global
VHF-LO is inherently very noisy with types of noise not seen on other bands and thus disregarded in simulations and tuner design.
Lower antenna gain on VHF-LO than other bands.
Many very strong FM stations also transmitted from CF (FM band is adjacent to channel 6)
All of these factors will make Global very difficult to revive and I doubt if an an antenna not designed for VHF-LO will cut it. Even then some antennas may not receive it reliably even if they do receive the other locals.
While it is possible to combine an VHF-HI/UHF antenna with a VHF-LO antenna, it is much easier to combine a VHF antenna with a UHF antenna since you can just use the separate inputs on the pre-amp (if using one).
One of the nice thing about the CM-7777 is it has separate amplifiers for VHF and UHF so when configured for separate inputs, it just feeds them directly into the appropriate amp, effectively giving each antenna its own pre-amp (though it does do some filtering first). This also increases overall signal capacity and reduces harmonic distortion from VHF to UHF. When using the combined input, it will band separate the signal first so it still uses both amps.
Because of all this, IMHO the best VHF antennas for Ottawa are either the Wade/Delhi VIP-302SR (available locally) or VIP-303SR (available online in the US). The VIP-302SR is only 4’8½” long (though about 9' wide at the widest, but rapidly tapers down) and should have more than enough gain for CBOFT and CJOH. The big question is how will it handle Global post transition.
For myself, I have ordered one of the last (if not the last) remaining 5Y6S cut channel Yagis for channel 6 (I should be receiving it next week). Initially I will combine it with my current antenna, but I hope to replace that with a small VHF-HI antenna and an HD-8800 (if I can get my wife's approval ;)).
2011-04-07, 02:38 PM
all the positive reviews I have heard about the HVR-950Q are from people with a good pre-amp so I don't know how good its first stage amp is.
Looking at the Product Brief for the XC5000 (http://www.xceive.com/docs/XC5000_prodbrief.pdf) (the tuner chip used in the HVR-950Q) it has a NF of 5dB, so unless Hauppauge added an external low noise input amp (unlikely) a good pre-amp would certainly help it in all cases.
2011-04-07, 02:53 PM
roger, your findings about the tuner is great !
I think this is something worth continuing the discussion in either the tuners, the preamps or both those special threads. It confirms my experience that adding a low noise preamp anywhere in the chain helps, and I assume we'll have this kind of problem with a bunch of other tuners if the 950Q has that much of a noise figure just on the input amp. We could continue that research for other tuners to see how far of a problem this can be. Especially in the context of Toronto users which are generally not using preamps for overload reasons, but where sometimes using a low noise figure distribution amp makes things better.
2011-04-07, 02:59 PM
roger, are you going for something like the 1713 for VHF Hi ? How do you plan on joining the 3 antennas if you go ahead with this plan ?
2011-04-07, 04:02 PM
roger, are you going for something like the 1713 for VHF Hi ?
For locals I think the 1713 is overkill. My thought is to go with either the Y5-7-13 (http://www.antennacraft.net/pdfs/Y5-7-13.pdf) or YA-6713 (http://winegard.com/kbase/upload/ya-6713.pdf) but I may also stick with my current antenna if it works.
How do you plan on joining the 3 antennas if you go ahead with this plan ?
I have a few ideas and haven't decided exactly which one I will use. Optimally I would have one pre-amp per antenna (the CM-7777 counts as two) and then using both a Join-Tenna and HLSJ (with one as a filter). Alternately I could use only a CM-7777 and combine the two VHF antennas.
I plan to draw my ideas and post them here when I get a chance.
2011-04-07, 04:21 PM
FWIW, i compared our 2 TVFools; you have a slightly better but almost the same Global 6 NM.
My vip302sr in the attic, with a good 15-20 feet between the antenna and the cm7777 on the roof, gives me a grainy but OK Global. But i only roughly pointed it north west, spending no time finding the sweet spot where it should be pointing so i could get it better. I'll be curious to see it come live in digital this summer.
2011-04-08, 12:12 AM
Thanks for the great input everyone.
HWP, thanks very much for the advice/recommendations and for re-posting my TVfool report for flavoie.
flavoie, you mention that you have one antenna (the vip302sr) in the attic and the other on the roof. Have you ever tried putting both in the attic? I am wondering if anyone knows how a CM4228HD would perform in an attic versus outside?
roger1818, I appreciate your recommendation. Also, since your setup is in the attic, do you find that you get all of the channels available? Is it an amplified antenna? Are you planning on putting your new channel 6-specific antenna in there as well?
Thanks for your help once again.
2011-04-08, 02:12 AM
rabbitears: jrmclean, who posted just before you, has such a setup, with separate UHF + VHF antennas in the attic.
His reception area is different than yours, but more importantly, the roof and other houses around you may be different as well. I have been impressed at what he's been able to achieve just in his attic, but roofs and surroundings, trees, other houses, can make all the difference when it comes to reception. We just can't estimate what it would be like for you. You can always try it out in the attic first if you like. Your roof will attenuate the signal before it comes to the antenna(s) and you will get worse reception compared to a roof antenna.
I have to warn you that it can be deceiving. The signal will be best at night and worse during the day. When there is bad weather, signal gets worse too. Having an antenna on the very best location essentially gives you more signal margin so it still works when the signal goes down because you're still getting enough. This is where you could lose a station when your antenna is in the attic during bad weather but be completely fine when the antenna is on the roof.
2011-04-08, 12:48 PM
Also, since your setup is in the attic, do you find that you get all of the channels available?
I bought my current antenna before I knew anything about them, so that is my biggest limitation (it does poorly with VHF-LO (2-6) and upper UHF (above ~55?)) so Global is very intermittent (varies from very noisy to very watchable), CFMT-TV(60) and CITY-TV(65) are poor (though I can get them digitally now) and I cannot get CJMT-DT(66). I am not able to see any of the American broadcasts, but was able to occasionally get them (poorly) when they were analog.
Is it an amplified antenna?
It is, but not a very good one.
Are you planning on putting your new channel 6-specific antenna in there as well?
Most likely since my wife probably won't let me put it on the roof. It is going to be a challenge to get it to fit as it is about 6'x6' and I need to have it rotated about 45 degrees from the trusses.
Hmm, CF is angled towards the back (and side) of the house, so I wonder if she would let me put it (and the VHF-HI antenna) on the back side of the roof, hidden from the view of the street. The UHF antenna will need a view towards the street though, but I might be able to hide it from most angles.
2011-04-08, 02:01 PM
Roger if you check my pics I used a slope tripod on the backside of my roof to hide the antenna from the street from most angles.
The antenna clears the roof but walking from the street you would not see it when looking straight at the house.
2011-04-08, 03:11 PM
flavoie, That is exactly what I was thinking. I doubt if I could put all three antennas on it, but I might be able to put the 2 VHF antennas on it, though it might be tight without extending the mast. If the 5Y6S is 6'x6' and at a 45 degree angle to the house, it will be 4'3" from the mast to the roof (along the diagonal). I don't know what my roof pitch is, but if it is 45 degrees the 5Y6S needs to be more than 4'3" up the mast, which doesn't give me enough room above it for the VHF-HI antenna.
Will have to give this some thought.
2011-04-16, 02:34 PM
I have ordered one of the last (if not the last) remaining 5Y6S cut channel Yagis for channel 6 (I should be receiving it next week).
I received my 5Y6S (http://www.wade-antenna.com/Wade/cutchannel.pdf) last night. It sure is a thing of beauty (though my wife laughed when I said that ;)). Now to find time to install it.
2011-04-16, 02:37 PM
Before you put it up is there any chance you could take lots of measurements and a photo or two for the Antenna R&D Forum folks to build some computer models? :)
2011-04-17, 04:59 PM
Sure. I will try and get some measurements. May not get any good photos of it unfolded if I choose to install it in my attic, but maybe one of the other guys who also bought one can get photos (there were four of us).
2011-04-17, 09:02 PM
Is there a repeater on the Canadian side for 57.1 PBS? I am picking it up with my new DB8 in my attic and was wondering if it was really pulling in something from 93 miles away.
2011-04-17, 10:45 PM
You have a (small) positive Noise Margin for WCFE on your TVFool, so with a DB8 in the attic, you should be getting WCFE most of the time. (On the roof, you should get it all the time).
No, it's not a repeater.
Over the past year, you may have had trouble getting 57.1, because the Communications Researh Centre had an experimental transmitter on RF channel 38, which is the same channel that 57 uses. CRC's 38 has since moved to 54 and then 51, so there is no longer any local interference to 57.
2011-04-17, 11:05 PM
Actually I just set up my antenna today. looking forward to getting rid of Rogers.
2011-04-18, 07:05 PM
It's all about gain at Channel 6. Since the 7-13 antenna is optimized for channels 7-13 I doubt it will be any good for channel 6, thus finding a VHF lo&hi antenna such as the vip302sr, a single cut yagi 6 like roger, or a VHF lo only antenna will be way better for global at 6.
A VHF lo&hi like the 302sr has the extra benefit of topping the 4228hd on VHF for 6, 9 & 13 in Ottawa, all post-transition channels global, src, ctv
2011-04-19, 08:11 AM
Are you guys with towers reliably getting US networks? Trying to sell the wife on a tower mounted antenna.
2011-04-19, 08:59 AM
Depends on your location
I get both PBS and wnyf(CBS,fox) reliably but lots of people in Ottawa can't.
Best way to know is for you to create your own tvfool report and post it here for fellow posters to help you figure which channels are attainable.
Edit: I just noticed your tvfool. Wnyf is attainable !
A roof or tower mounted antenna, with preamp, without a lot of trees around, should work.