Moving - Can I expect to get these 2edge stations?

[Canadianeh]

Good evening,

I'm moving to a new house in a couple of weeks, and am hoping to be able to pick up a couple stations from Montreal, Canada.

TV Fool report: http://www.tvfool.com/?option=com_wr...d243ead23d645f

I'm thinking of getting a 91XG to hopefully get the following stations. You may need to choose "all pending applications" channels to see some of these for some reason, even though they've been live for years:

21 - CBMT
15 - CKMI
49 - CJNT

Do I have any hope of picking up 15 and 49? Antenna will be around 20-25 feet high (HA restrictions). Would there be a better choice for an antenna?

I'd also like to get 12 - CFCF, but am fine using a separate VHF antenna for that, rather than compromise on a less effective UHF antenna - but if there is a better combined choice, let me know!

Also, I am looking for recommendations on a VHF antenna for the ABC station WVNY - 13. I will use an existing DB4 antenna, if it pulls them in well enough (slightly concerned about WFFF/FOX 43.

Cable runs will be short (under 50').

Please let me know your thoughts on this. Open to preamp ideas, as well. Thanks!

[timgr]

This is my take on this - I'm an engineer but not an antenna engineer or part of the industry. Somebody with more experience can correct me if I make a mistake.

Ok, 15 CKMI has a noise margin of 2.5. So that's 2.5 dB above the minimum amount of signal needed to receive that channel. 2.5 dB is 20 log(Srcv/Smin) where Srcv is the amplitude of the signal to be received, and Smin is the minimum signal amplitude in the air that can be reliably received. So Srcv is 33% higher than needed, theoretically, if your antenna has a dB gain of 0 (unity gain). Now, most antennas have a dB gain figure. You can add that to the in-the-air signal strength to get an idea if you are going to be able to receive the channel.

NB this is ideal behavior. Confounding circumstances like trees or buildings blocking the signal path will change the outcome. And local topography matters too.

CIVM is -2.0 dB. Don't know what to say about CJNT, since it's not on your plot. Not sure what you are referring to with selecting pending applications.

Typically your good TV antennas have gains in the high single digits or low teens. For example, the very sensitive UHF-only Antennas Direct DB8e has a peak gain between 14 and 17 dB, depending on the station frequency. Usually the industry people on this site recommend Antennas Direct or Antennacraft antennas, apparently based on performance and build quality.

For WVNY I would use an Antennacraft Y5713 http://www.antennacraft.net/Antennas/AntennasVHF.html and combine that with the DB4. I presume you have a plan for combining these sources?

If you want the high VHF capability and don't want to have another dedicated VHF antenna, you could go with one of the Antennacraft HBU series antennas. I'm reluctant to recommend a specific antenna because I don't have any experience with the products ... but you can get the HBU44 for the same price as the 91XG and have VHF capability.

[timgr]

Ok, figured out the pending applications thing. So CJNT is at -7.1 dB at that height. Looking at the HBU44, it has an 8.2 dB gain. So 8.2 + -7.1 = 1.1 dB noise margin. That's 13.5% over the minimum signal needed to receive that station - not much margin.

CJNT runs at 683 MHz, and your 91XG has a gain of about 17 there, so your NM is about 10, or about 3.2x above minmum signal level. This seems like a more reasonable margin. You could add another Y5713 to the 91XG mast to add CFCF, if you wanted that. Or WVNI is close to 180 degrees from CFCF, so you could maybe use a Y10713 and pick up WVNY off of the backside of the Y10713 pointing at CFCF.

If you will be in the USA, your HOA doesn't have much say in your choice of antenna height. Here are the rules - http://www.fcc.gov/guides/over-air-r...n-devices-rule

[Canadianeh]

Thanks, timgr. That was my conclusion, as well but have never tried to lock a station that had a negative NM. I currently live about 5 miles LOS to the Vermont towers, so they have a high NM, and the Canadian stations are just too far and weak from my current location. I'll be moving in early December, so I'll post my results at that time.

If anyone else has any other thoughts, just let me know.

Thanks!

[whatistv]

most of my station were 50 miles away and the 91xg worked great for me. only $44 open box.

http://forum.tvfool.com/showthread.php?t=14972

[Canadianeh]

Originally Posted by whatistv

most of my station were 50 miles away and the 91xg worked great for me. only $44 open box.

http://forum.tvfool.com/showthread.php?t=14972

Thanks, WhatIsTv. By any chance, can you list out any of the stations you are able to get that are negative NM numbers on your TV Fool report? I'm just trying to see what is truly possible with this antenna, and my expectations.

Thanks!

[whatistv]

Most of my stations, the ones that I wanted anyways, were NM(dB) between 10-20. These particular stations are all 2Edge and 49.3 and 51.4 miles away. The antenna also picks up one stations that is NM(dB) of 43 and is 10 miles 180 in the opposite directions.


I did not attempt to pick up any neg. signal stations. There seems to be one that I could get with a signal of -3.4. I do not get it with my current set up. Keep in mind my antenna is pointed directly at my house.

[Canadianeh]

Yes I saw your picture.. too funny. Just one last question, when you saw the negative NM channel cone in, was re antenna pointing through the house at that time?

[whatistv]

I must clarify I have NOT had any negative NM channels come in. The channels that I do get are from 10-20NM(dB).

This weekend I will be up there messing with the antenna and installing a more permanent mount as well as cable clasps. When doing this I will attempt to get the negative NM station by holding the antenna above that second higher roofline and rescanning for station. I should be able to post back Sat. evening with my results then.

[whatistv]

Sorry I was unable to test the reception. The weather did not cooperate. My eave mount should be here in a few days and I will try then!

[Canadianeh]

Originally Posted by whatistv

Sorry I was unable to test the reception. The weather did not cooperate. My eave mount should be here in a few days and I will try then!

No prob... it's rained all weekend here too.

[Canadianeh]

So, reading the forums a little more, I'm now debating if I'd be any better off using the 91XG or the DB8e, as I plan to at least start off mounting the antenna in the garage attic. I've read about all of the ill-effects of doing so and am prepared to drag it outside if necessary. The garage is non-insulated, plywood, and vinyl siding, so I'm hoping it won't attenuate the signal *too* much.

That being said, would the 91XG or the DB8e be any more effective than one another in an attic like this?


TV Fool report: http://www.tvfool.com/?option=com_wr...d243ead23d645f

Channels attempting to pick up somewhat reliably:

21 - CBMT (19.4 NM)
15 - CKMI (2.5 NM)
49 - CJNT (-7.1 NM)

Note - to see these on the report above, you need to choose the box to see "pending applications" as well. Not sure why they've fallen out of the database of live channels.

Also, will channel 38 off to the west (41.2 NM) affect my signal here? It would be nearly 90 degrees off from where the antenna is pointed. I'm slightly concerned about whether or not it would cause an overload situation, in the event I need to use a pre-amp.


Edit: Lastly, there is the following channel as well:

12 - CFCF (12.9 NM). I know the 91XG has no hope of picking up this channel, but would the DB8e be able to? I can't find a good modeling graph of the DB8e across the frequency spectrum online. I'm assuming I'll end up having to pick up a Y5-7-13....

[whatistv]

Well I got my eave mount and put my antenna about 2 foot above the upper roof. I do get my signals better but nothing crazy impressive.

I found the signal strength meter on my tv. Well it says signal quality. All the ones that come in start at a signal quality of 10 and the highest number is 34.

All the stations look the same to me being that i do get the signals. I took a picture of what the antenna was pointing towards and its nothing but a wall of trees. I am not about the house though...

Sorry but I DO NOT get any of the negative Db stations in with my antenna.

[Canadianeh]

Good to hear. Thank you for the reply!

[Canadianeh]

So, I still haven't moved yet, but for the fun of it, I tested out doing a channel scan with a Hauppauge 950Q and it's cheesy little stick antenna in the driveway, and was able to get the following stations with ease:

Vermont cluster (Real Phys. channel):
WCAX - 22
WPTZ - 14
WETK - 32

Montreal Cluster (real phys. channel):
CBFT - 19
CBMT - 21

While I didn't get a chance to write down the SNR received on all channels, I was surprised that CBMT came in with approx 23 SNR ratio. Seeing that the NM value TVFool gave was 15.9, I think this might be promising to state that the TVFool report for my area may be a little more pessimistic than reality.

Things to note:

- I was not able to pick up any of the VHF stations, probably due to the crappy stick antenna and the larger wavelength of VHF:
10 - CFTM
12 - CFCF
13 - WVNY

- I was unable to find the following Montreal stations in my scan:
15 - CKMI ( 2.5 NM)
49 - CJNT (-7.1 NM)

And the following Vermont station was just under the digital cliff:
43 - WFFF (10.0 NM)


Knowing this report from the crappy single pole antenna, and the fact that I'm going to likely go with a 91XG for Montreal UHF, a CM4221 for Vermont UHF, and possibly Y-5-7-13's for both VHF clusters, am I likely to be happy with a reliable setup here on the stations mentioned above - including the ones listed above that the channel scan couldn't find?

One thing I noticed is that if I map out the TVFool reception from Montreal that shows signal degredation about 2 miles ahead of me in the path to the tower is a "hill" that has since been turned into a rock quarry, and is probably not the height that TVFool and the terrain database think it is any longer (especially with CBMT coming in crystal clear at 23 SNR). This might be the reason for the report to be more pessimistic than reality seems to be here, so far. To the untrained eye, I have a thin tree line about 800-900ft away (bank of a river), and the other side, where this hill supposedly is, seems pretty flat... at least no higher than the tree line by any means.

Also, playing with TVfool, I'm about 45' from being LOS to Montreal, assuming the "hill" in front of me is accurate in their terrain databases. Raising my antenna to that 50' level in TVFool raises 15-CKMI to 13.3 NM, and 49-CJNT to 4.0 NM.

[Canadianeh]

Good morning,

So We're finally moved. Yesterday, I put together the 91XG antenna and it surprised me in some ways, and disappointed me as well in another. The 91XG is able to get 12-CFCF with about 85% signal strength - which would save em from needing a VHF antenna to point North. It also has no trouble picking up 21-CBMT and 15-CKMI. Unfortunately, anything I tried would not bring 49-CJNT up to a viewable level.

Test was:
Place antennas in 2nd story window to get a "feel" for the elevation and angle requirements, as my garage attic is open - so it requires a 16' ladder to "test". The 2nd story window provided some interesting results:

49-CJNT: - 91XG with RCA Amplifier and Hauppauge 950Q - ~12 SNR (15 required for picture, and 30 is max)
49-CJNT: - 91XG with CM 7777 (old) and Hauppauge 950Q - ~12.5 SNR

Ironically, I took my old DB4e and performed the same tests:

49-CJNT: DB4e with RCA amplifier and Hauppauge 950Q - 16 SNR (it tunes!)

49-CJNT: DB4e with CM 7777 amplifier and Hauppauge 950Q - 16.5 SNR (slightly better)


I find it odd that the 4-bay antenna with a much less gain rating would pull in this low powered station better, especially since 38-WCFE is 90 degrees off and LOS, as well as pretty strong. In all tests 38-WCFE comes in strong 90 degrees off axis.

Can anyone else think of a way to possibly squeeze out another couple DB to ensure my signal strength is sustainable for 49-CJNT? According to the TVFool map, the further to the East I go (toward the garage), the NM goes up ever so slightly. I've also read good things about the new Hauppauge 1265 being more sensitive than the 950Q, so that might be an option.

Would the 8-bay DB8e be a better choice than the 91XG after all, based on my findings?

TVFool report is in the first post.

Thank you all!

[Canadianeh]

I actually mounted the 91XG with the CM 7777 out in the garage attic at approx. 14' in the air, and am now getting CJNT at 20-21 SNR on the Hauppauge 950Q. All of the other Montreal UHF stations are coming in as well, with the exception of the offline 29.1 - all of the others with a SNR of 23 or greater (CBMT is 27).

The 91XG was able to get 12-CFCF in the house reliably, but not in that position in the attic. I'll live with where it is, since it's getting all UHF stations better than I expected, and eventually build the 2-bay VHF bow-tie antenna (plans by holl_ands, I believe). My only fear is that the direction of the antenna forces me to point through the roof (plywood and asphalt shingles) instead of through the exterior wall, so moisture may play a factor here. It's snowing tonight - would a couple of inches of snow on the roof give the same effect as a wet, soggy roof? I'm just trying to see what the "worst case" signal strength ends up being.

Thank you all for your help.. greatly appreciated!