... Would the spacing be enough to avoid interference ...

The interference caused by two antennas isn't going to be dominated by the separation distance between the two antennas. Rather it will likely be dominated by the out of phase signals received at each antenna. E.g., the amount of primary signal received on axis by each antenna, combined with the same signal received at the back side of the other.

A quick look at 'Mississauga, Ontario' on tvfool tells me you've one cluster of fairly strong stations at 60 degrees and another at 197 degrees.

Your antennas would therefore be optimally pointed 197 - 60, or 137 degrees apart. To better visualize it means the signals received primarily at the front of the antenna pointing to a source, will also be recevied about 45 degrees to the side of the rear axis of the other antenna.

You'll be dependent on front to back (F/B) ratio, at 45 degrees off rear axis. Maybe someone on the forum knows what the polar plot looks like for the 4221HD; I don't know it off hand.

Although a few of your stations are VHF (and the 4221HD is primarily a UHF design) those VHF stations may be strong enough to be receivable.

I'd say just try it. If you have a receiver that has both AGC and S/N indicators, and you have a marginal S/N ratio (poor "quality") for a station that otherwise has an AGC level similar to other stations with good S/N ratio, you might suspect interference. In that case you might try just putting some tin foil on the back screen to improve the F/B ratio. Perhaps try to extend the size of the screen with a little overhang...

If you experience difficulty with the Buffalo stations, I would recommend going with a separate feed for each antenna to the TV. You can then use an A/B switch at the TV to switch feeds.

You know what the irritating problem can be with an A/B switch, and most DTV tuners?

Most tuners have an all or nothing scan algorithm only. Not many I've seen have a "learn more" option. So you start by switching to A and hit "Scan" and learn one set of channels. But obvioulsy if you switch to B there's a different set of channels there, and if you hit scan again on such sets it learns the set of channels predominant on B and will forget about some A channels! Only the subset of A channels that happen to be good enough to also be receivable at the B antenna will be included.

:confused:

This can be an issue with using a rotator as well....

Thus the reason it's important to test a tuner's scan method prior to purchase.

this is the tvfool results for my location:

http://www.tvfool.com/?option=com_wrapper&Itemid=29&q=id%3de07cab85653421

Would one 4221HD then be better instead or two.

Try with just the BUF antenna first and see what you get. I find I get most digitals from TO, even though my stack is peaked for WNYO. For those I don't get, I check out the analog, and if need be, switch to my TO antenna for the digital. Hopefully by August all the TO stations will increase the juice so those in the GTA just aim for BUF and still get TO...

Freeair you should try with just the 1 antenna first at buffalo.After August the Toronto digitals will be powering up full and all channels maybe be fine with just the 1 antenna.

Freeair you should try with just the 1 antenna first at buffalo.

Hmmm.... that's a different TVFool than just typing in 'Mississauga, Ontario'

Nevertheless, I'm bettin' with rob50312. I've got $5 that says a single 4221HD with the reflector removed and aimed at approximately 90 degreee gets you the top 15-20!

Can't tell which cluster (compass heading) is the cluster that is Buffalo. If those are your weaker ones, then yeah - go Buffalo!

Mississauga's land area is huge for a municipality, so his TVFool appears different.

Hmmm.... that's a different TVFool than just typing in 'Mississauga, Ontario'

Nevertheless, I'm bettin' with rob50312. I've got $5 that says a single 4221HD with the reflector removed and aimed at approximately 90 degreee gets you the top 15-20!

Can't tell which cluster (compass heading) is the cluster that is Buffalo. If those are your weaker ones, then yeah - go Buffalo!

I put in my actual coordinates found by using google earth. I am right on the border of Mississauga/Milton. When using just 'Mississauga, ON' i get a different TVfools report.

So should i still do the 3 hacks as well as remove the reflector?

Try first on the stock, and then mod as you go.

I went to saveandreplay today to get a 4221HD and the guy working there mananged to talk me into getting a Antenna Direct DB8.

He told me to point towards Buffalo and I should get those stations and Toronto easily.

He had it hooked up in the store at the Mississauga location and the channels were close to 90%.

I have the original 4221 in my attic. I'm at Creditview and Bristol and get every channel. Ch 2 (NBC) drops out occasionally in the winter due to cold weather and snow on the roof. I have it pointed at Buffalo and get Toronto through fringe.

You may have some challenges fitting the Antenna Direct DB8 through your attic access door. Best of luck.

Osprey Blvd? Then we’re neighbours!

Please put that beautiful antenna on the roof of your house where it belongs.

ok so i put the Antenna Direct DB8 in my attic and it is pretty good. I am using a CM 7777 preamp and just over 80ft in cable. I can probably get it down to about 60ft. Most of the channels right now are between 60-80%.

I get the following channels:

Digital:

2-1
2-2 occasional pixelation (but there was snow on the roof today)
2-3
4-1
5-1
7-1
9-1
11-1
17-1
17-2
17-3
23-1
25-1
29-1
29-2
36-1
41-1
44-1
57-1
64-1
66-1

Analog (these are channels that i can see clearly with not much snow)

5
9
11
19
25
36
47
57
69

I managed to shorten the total cable lenght to about 52ft for my attic install. I am now getting 23 channels but 49-1 and 49-2 pixelate. All other channels are strong and do not cut out or pixelate but are at between 60-80% strength.

Here is a summary of the setup for the cable going from the antenna to the tv:

a) Balun to Preamp (CM7777) (1.5ft)
b) Preamp to ground block (20ft)
c) Groundblock to Preamp power supply (30ft)
d) Powersupply to tv (1ft)

1) Would there be any 3db loss at the connections at the ground block and powersupply?

2) Is it possible to add a second less powerful preamp right after the CM7777?

3) I have a ground wire from the block tied to the ground in my service panel. Since it is in the attic would another ground wire need to be run from the j-pole? There is the occasional draft in the attic.

Thanks for the help.

try going here, and plug ur numbers in to that sheet.
http://www.digitalhome.ca/forum/showpost.php?p=1218150&postcount=2446

You can plug in a 2nd pre-amp in place of one of the blocks downstream there,
like in place of something insignificant, like a jmpr or the splitter. I think u'll find the 2nd pre-amp doesn't buy you anything.
But don't listen to me, plug in numbers from ur setup and see.
I think u'd probly be better off playing with ur antenna positioning.

d) Powersupply to tv (1ft)

I'm not sure if running that powersupply cable so short in length could create noise given that it's right at the TV. Noise could kill some of your gain.

49.1 is a difficult channel. I doubt there is much you could do to improve it.
More amplification is not recommended, as you're at the high level already--the CM7777 isn't recommended for use in the GTA. Too much amplification will only cause problems for you...

The preamp will compensate for any line losses. You don't say what antenna is in the setup. A higher gain, more directional antenna might help. Placing the antenna above the roof would also help.

Antenna Direct DB8 ... think i have to move it a few degrees as I used the true values instead of magnetic values from tvfools when pointing it.

off topic how are the HDHomerun tuners compared to a built in TV tuner? I have an LG50PS60.

Freeair try turning your antenna slightly more east and see if 49 improves as they are a little more east than the other buffalo stations.WNYO 49 is always 100% for me.My TV fool says LOS to WNYO.If not then moving above the roof is your only other option.