TV fool results;

http://www.tvfool.com/?option=com_wrapper&Itemid=29&q=id%3dcd7271cda15643

Primarily interested in DTV.Presently inherited 30ft tower(and pole) plus CM rotor(must replace).No ant preamp but want CM7777 asap.Lots of tall trees50-80FT!(evergreen)here but signals like 18-1/2/3 getting thru consistently.Is Digiaire pro signal finder a good idea or just be guided with TVfool results?Considering 91XG as DIY GH not likely for me.
Ron.

Some people like the Digiaire Pro signal finders, others don't. You can read or ask about them and other types in here:

Signal Analyzers and Meters for OTA (http://www.digitalhome.ca/forum/showthread.php?t=96705)

Primarily interested in DTV.Presently inherited 30ft tower(and pole) plus CM rotor(must replace).No ant preamp but want CM7777 asap.Lots of tall trees50-80FT!(evergreen)here but signals like 18-1/2/3 getting thru consistently.Is Digiaire pro signal finder a good idea or just be guided with TVfool results?Considering 91XG as DIY GH not likely for me.
Ron.

Looks like you are in a good location. Not sure what atnenna you currently have, but it may not be worth replacing it if you can pick up WNPI (18.x) reliably. The key is to get that rotor working.

As for a pre-amp, that depends more on your setup? Are you splitting the signal to multiple TVs or do you have more that about 50' of cable? If so, it could be useful, otherwise it likely won't help much.

Regarding the signal finder, if you are using a rotor, I probably wouldn't bother as long as the signal strength meter in your tuner works reasonably well. The signal finder is great when aiming antennas manually as you can bring it up on the roof with you and see the effects immediately.

Word of warning about the 91XG. It is a UHF only antenna, so it won't work very well for any VHF stations (such as WWNY. CJOH and CBOFT are also likely to be on VHF post transition). You could always combine it with a good VHF only antenna though.

Roger1818:
Thanks for that input esp since we are close at hand and have similar problems,if not solutions.
My antenna looks like about 50element VHF/UHF CM?(channel master).I always thought it could serve as VHF local backup antenna on separate manual switch.Thus 91XG should do most of what I want.New CM 9521 rotor is part of the plan and is a key part.I am presently using 50ft RG6 and plan to run same to 91XG.Hoping to get comments on my TVfool results or better still get you to sample libations while seeing site.:cool:
Ron.

Hi from Barrhaven,

Here are the results of my tvfool report.
http://www.tvfool.com/?option=com_wrapper&Itemid=29&q=id%3d9fbee5563ba1e0

Could you please give me some feedback on whether one omni-directional antenna like the 3000a would be useful, or if I should go with two directional antennas.

I have the money, time, and facilities for both, so it's just a question of which.

Thanks,

Vince

vfgilber, it all depends what channels you want to receive.

An omnidirectional antenna will not receive any of the American channels. There is also a good chance it won't receive CJMT-DT since the antenna's gain rolls off for the upper channel frequencies. Global (analog channel 6) will also likely be very poor.

If you go the two antenna route, you would be much better off using an A/B switch to select the antenna than trying to join them together.

For UHF, a third option would be to use a reflector-less antenna and try to receive signals off of both sides. At 126 degrees separation between the two local towers, this might work. You would then need a separate antenna for VHF.

vfgilber, it all depends what channels you want to receive.

An omnidirectional antenna will not receive any of the American channels. There is also a good chance it won't receive CJMT-DT since the antenna's gain rolls off for the upper channel frequencies. Global (analog channel 6) will also likely be very poor.

If you go the two antenna route, you would be much better off using an A/B switch to select the antenna than trying to join them together.

For UHF, a third option would be to use a reflector-less antenna and try to receive signals off of both sides. At 126 degrees separation between the two local towers, this might work. You would then need a separate antenna for VHF.
It also depends on whther you want only digital channels. For digital local channels, you may be able to get by with a single rooftop antenna aimed midway between the two towers. There is enough signal in the air for you to get the loal channels off-axis. However, you may suffer from un-watchable ghosting on the analog channels.

You are well positioned for an external antenna to get PBS and possibly even CBS and Fox with an antenna pointed towards the states.

Hi TVLurker and Roger1818,

I'm really confused. My goal at the moment is to have one mast on my roof with an antenna that will pick up channels from the two towers roughly north and south of my house (almost 180degrees) without a rotor or having to flick a switch every time I flick back and forth between two channels that happen to each come from one tower.

Could I get away with a double-bay gray-hoverman without a reflector (or strip the reflector off a CM4228) for the digital, and then add a vhf antenna above it at the top of the antenna to get the analogue channels?

I really just want to have a few channels for the one-hour-max I watch each day.

Thanks,

Vince

roughly north and south of my house (almost 180degrees)

I'm not sure what you mean. Camp Fortune is at 0 degrees magnetic, Herberts Corners is at 124, and South COlton (WNPI/ soon WNYF-LD) is at 154.

If you're only trying to get local stations, a single antenna pointed at 60 degrees should get you both towers in digital. You may have to favour one direction or another to get the weakest station (CKXT-DT from CF, CITY or OMNI2 from HC).

If you want to get WNPI, you might be able to get by with a reflectorless antenna, but you may run out of margin during bad weather.

Also, a reflectorless antenna may make WNPI harder to get, as you way be more susceptible to adjacent channel interference from CBOFT-DT on 22 and TVO on 24 from camp fortune.

To get WNYF-LD (Fox/CBS from South Colton, starting next month) you would probably need a a high gain yagi to avoid adjacent channel interference from CITY-DT at Herberts Cornes (HC) on 17.

So the bottom line is, what stations do you want to get:

1. All analog ghost-free (a moot point in 14 months, as they will be gone)
2. All local digital (for now, CBC, SRC, SUNTV, OMNI1, OMNI2, CITY. by Aug 2011 all 15 local stations, give or take SUNTV if they decide to shutdown OTA)
3. PBS from South Colton (WNPI Norwood) and/or Lyon Mountain (WCFE Plattsburgh)
4. CBS/Fox from either South Colton, or Watertown (would require a deidicated channel 7 VHF-Low antenna)
5. CKWS CBC Kingston from Franktown, for now in analog

So the bottom line is, what stations do you want to get:

1. All analog ghost-free (a moot point in 14 months, as they will be gone)
2. All local digital (for now, CBS, SRC, SUNTV, OMNI1, OMNI2, CITY. by Aug 2011 all 15 local stations, give or take SUNTV if they decide to shutdown OTA)
3. PBS from South Colton (WNPI Norwood) and/or Lyon Mountain (WCFE Plattsburgh)
4. CBS/Fox from either South COlton, or Watertown
5. CKWS CBC Kingston from Franktown, for now in analog

Just adding my experience (I am exactly 180 degrees between towers)

compare your tv fool with mine: http://www.tvfool.com/?option=com_wrapper&Itemid=29&q=id%3d9fbe7e737d1903

and I get TV Lurker's 1 and 2 with a very simple set up - CM4221 with reflector removed, your angles are quite a way off so pointing a reflectored antenna between them could work as has been said. Options 3,4 and 5 are theoretically possible for me too but probably a lot of work. My couch is too comfortable. You might have a better chance (or a bad couch).

(Also TVlurkers 2nd option typo should read CBC, not CBS)

(Also TVlurkers 2nd option typo should read CBC, not CBS)

Thanks. I've now corrected the original.

I'm not sure what you mean. Camp Fortune is at 0 degrees magnetic, Herberts Corners is at 124, and South COlton (WNPI/ soon WNYF-LD) is at 154.

Sorry - when I reran TVfool today, for some reason, it was showing me Nepean proper instead of Barrhaven. I'd forgotten that the angles are way off.

Looking at those options, I believe options (2 + 3) or (2 + 4). I'm just not sure how to accomplish it. One CM4228 aimed between the two towers and then one yagi to pick up CBS/Fox. If I understand correctly, I'd use a combiner to put the two antennas into one feed?

You don't need a 4228 to get the locals -- it has more gain than you need, and has a narrower beamwidth that you want. Any UHF outdooor antenna will do. A 4221 should be fine.

The tricky part with combining a yagi for 18 and 23 is that now you're combining strong signals from 17, 22, and 24 in with weak signals from 18 and 23.

Depending on the length of your coax, I would go with a low-noise preamp on 17/23, and then combine it through a splitter with dc passthru with an UNamplified antenna pointed at the locals.

This should even out the relative levels of the local and distant stations.

Alternatively, you could try a 4228 aimed at South Colton and see if it picks up local digitals adequately off the back and side. In that case, the preamp should hurt you too much.

Do you really think that a 4221 aimed between the two would pick up signals? Saveandreplay shows the 4221 as having a 45degree beam width.

We have been giving advice here for years before the nice folks at that store started offering OTA gear. Go with the advice you got here. :) Also did you find anyone earlier in this thread who lives nearby? You can tell a lot from their situations how to best proceed.

Will do.

I have been reading through all of them, and while I've garnered knowledge in general, not many postings actually talk about what specific gear people have up on their roofs. There didn't seem to be much treatment of the issue of pulling signals 180degrees (or around there) from each other.

a 45degree beamwidth means that at 22.5 degrees n each direction, your received power will be down 3dB (which means it will be half the power).

But TVFool at 10 feet for Greenbank and Fallowfield shows that Camp Fortune stations have a noise margin between 34 and 56 dB.

So losing 3dB won't be noticeable. (But it will drop off steeply after that, and at some point you could have a 30dB null towards Camp Fortune which would kill CKXT (if Quebecor doesn't do it first LOL)

Where it would be noticeable would be on the US stations.

Well,

I needed something to tide my wife and her mother over the weekend while she is visiting. I whipped up a Stealth Hawk with Home Despot parts, and put it on a 6ft wooden pole off my chimney. I ran the cable through one of the orphan wires running from old ExpressVu dishes that were just left on the roof.

All the local digital and hd come in perfect. The analog are all a bit fuzzy and have a bit of ghosting. It will do until either tomorrow or next week when I pick up a new antenna.

I'm quite surprised at the quality of the digital and hd channels. A really nice surprise.

After I erected the antenna, I returned some spare parts to Home Despot and picked up one of their cheap plug in 10db plug-in amplifiers to see if it would help. I'd already put away the ladder, so I installed it at the breaker box in the basement where the main splitter is. From the antenna to that point is about 65ft. It clarified the analog channels a bit, but not $22 worth.

However, when I was installing the antenna in the first place, I had it plugged directly into a tv via a 50ft coax down off the room and in a window. The analog channels were almost as fuzzy, so it might be my build quality on the Stealth Hawk. It literally took me about 20minutes, so nothing is really spot-on. I had to strip and straighten out twisted 10-3 wire, so the elements aren't dead-straight.

I couldn't find any accurate diagrams which provide angles for the bends of the bottom whiskers (?). The images in the "Building the Stealth Hawk" thread have lengths, but I didn't find angles.

Still - for the time invested, very nice.

The analog channels were almost as fuzzy, so it might be my build quality on the Stealth Hawk.

More likely is because the antenna isn't pointing at the towers. The binary nature of digital broadcasts means you either get a perfect picture or you don't get it at all (although there is a small window where you will get bit errors, resulting in pixelation). With analog, the picture will gradually get worse and worse. For that reason, to get a good picture you need a stronger signal for analog than you do for digital. OTOH, you can watch a very weak analog signal where as with very weak digital signal not get anything.

Which direction did you point the the antenna? Assuming it is reflectorless, I would recommend pointing it at about -27 degrees (or 153 degrees) magnetic as this will be only 27 degrees from both towers (front for one, back for the other). You can then tweak it to optimize reception.