Thanks roger1818, that's what I needed to know. We discussed earlier... with the nice weather I'm going to get the work done finally and don't want to be disappointed and have to climb up there again.

Any other thoughts are appreciated..

I would potentially swap the atennas and put the VHF antenna higher than the UHF one. VHF is more affected by height than UHF. A quote from hdtvprimer.com (http://www.hdtvprimer.com/ANTENNAS/siting.html): Thus the rule of thumb: “Higher is always better” for VHF.

Actually, it's UHF that's more line-of-sight than the lower VHF frequencies. VHF tends to better diffract and consequently usually results in the UHF antenna being placed above the VHF antenna. Some of this is by convention rather than by rule. The bottom line is that the antenna has to be placed where the signal is present. That can only be determined by putting an antenna in the air and testing reception.

I suspect the quotation above is missing some context or is somewhat incomplete as written by the Mr Nist.

So I made the adjustment as per my original post. 5ft mast above a rotator, DB4e at the very top, YA17-13 at the very bottom, split VHF/UHF via CM778 all mounted on a rooftop tripod about 50ft up. Very pleased with the results, I finally have the setup I've been aiming for; capturing virtually all local channels quite solidly (except WPXJ, very rare) with minimal to no rotation required I'll post an update it the Toronto outdoor reception reception result with more detail.

I always thought the rule-of-thumb was to place a uhf-bowtie above the VHF antenna. But whatever gets you good results is the way you want to go.

I look forward to your update in the Toronto Outdoor thread!

leszek, as ADTech suspected, you have extracted and oversimplified a single quote from a complete article. That quote assumes you already have Line-Of-Sight (LOS). UHF reception will max out pretty quickly (at about 10 feet above LOS) because of its short wavelenth, but VHF needs more tower height than most people can feasibly have to get maximum signal strength (unless you live on the edge of a mountain or near the top of a highrise building).

I read on another forum that the supply of Join-Tennas is running out quick. The poster noted that the Channel Master Store no longer lists them for sale.
So, I already has an RF 8, and I picked up an RF 13 on eBay. I have piggy-backed the two per the following drawing:
http://www.digitalhome.ca/forum/picture.php?albumid=880&pictureid=5258

What's really great is that both RF 7 and RF 12 can get past the traps in the Join-tennas. While both are slightly weaker than with a direct connection, they are running SNRs around 22:1, which is plenty.

^^^ Not sure about stock levels, but CM moved the Jointennas to the PCT store and put them on clearance at a special price. They even have some UHF models available now (but you will need to tune them yourself).

lithOTA, that won't work. JoinTennas interfere with adjacent channels, so your Channel 8 JoinTenna will interfere with Channel 7 and your Channel 13 JoinTenna will interfere with Channel 12.

I think he stated that they work anyway...

Looking for some advice on ganging 3 antennas pointed in different directions.

I have another post with signal level readings here http://www.digitalhome.ca/forum/showpost.php?p=1399104&postcount=1154
I was looking for feedback in that forum, but I came across this forum and thought I could get some better help. Sorry for double posting, kindof.

This is my TVFool.
http://www.tvfool.com/?option=com_wrapper&Itemid=29&q=id%3d40334260635ee3

What is the best approach? two splitters
What should I be mindful of? with two splitters do all four inputs have to be equal length?

^^^Are you sure that TVFool report is correct? It doesn't correlate very well with your reception results (for example it shows a NM for NBC (WGRZ?) at --28.8dB, which should be un-receivable). Did you get your co-ordinates wrong? Is your antenna only 10feet above ground like the report says?

Trying to combine 3 UHF antennas is going to be problematic. I would try and limit it to at most 2 antennas. If you absolutely need 3 antennas, I would go with either a switch or separate tuners.

As for equal cable length, that is only required when combining identical antennas pointed in the same direction. When either of these is not true, cable length is irrelevant since the signals will already be out of phase and almost impossible to match (you need to isolate them instead).

My TVFool coordinates are correct. The elavation ma be off by 5 feet or so. I own a bugalow, so after the main leve all I have is attic. The antenna mast is anchored to a ceiling joist.

Maybe I just got lucky with weather conditions when I got NBC. I have not gotten it since.

^^^I suspect you were lucky then. Either your antenna is in a sweet spot that TVFool can't predict, or the weather conditions were perfect. Even without combining, I don't think you will receive any American stations reliably and the extra losses from combining 2 (let alone 3) antennas will only make things worse.

My suggestion would be to use one reflector-less antenna to receive everything from both the east and west as there will be less signal loss from not having a reflector than from the combiner and it will avoid other issues. For VHF, you might want to add a dipole (even a cheep $3 pair of rabbit ears from The Source) or folded dipole connected to the VHF input of your CM-7777 (remember to switch it to use separate inputs).

If you really want to play with the American stations, have the antenna connected to a separate down-lead and use an A-B switch to select it, though I suspect more often than not you won't receive anything.

lithOTA, that won't work. JoinTennas interfere with adjacent channels, so your Channel 8 JoinTenna will interfere with Channel 7 and your Channel 13 JoinTenna will interfere with Channel 12.
You're right, it shouldn't work, but it does. 7 & 12 are the two strongest (about 25 NM), then 13 (15 NM), and 8 is the weakest (-1 NM). If I run 7 & 12 directly from the K6STI to the tuner, they both will have SNRs of 26-27; so they do lose about 4-5 points of SNR to the Join-tenna traps. I'm pretty sure that my RF 8 could not get though the trap in an RF7 Join-tenna, so I guess it works better to buy one for the weaker station.
I will have to take a look at those on the PCT store...didn't know about that.

Hey
I have a 2 year old CM 3671 on a rotator and running into a Electroline amp. I recently took down an old 3671, from the 70's? (I'm assuming that is what it is. It is nearly identical to the newer one I have). I placed the old 3671 about 7-8 ft below the newer model. The old 3671 stationary and is fed into an old CM 0064 pre amp. I then took both feeds and put them through a splitter to try to combine them.
Here are the results.

Newer CM only, facing Hamilton:
6.1 (global) 60-70%
11.1 (CHCH) 30-40%
13.1 (CTV) 80-85%
36.1 (CTS) 25-30%

Older CM only facing Woodstock:

6.1 (global) 60-70%
10.1 (CTV2) 25-30%
13.1 (CTV) 80-85%
31.1 (CITY TV)50-55%

Together (antennas in same positions)

6.1 60-70%
13.1 80-85%
31.1 50-55%

I was really hoping to pick up 11.1 and 10.1. I was wondering if anyone had any thoughts or ideas about how to gang these CMs properly.

http://www.tvfool.com/?option=com_wrapper&Itemid=29&q=id%3d3e47610c19a3a0

In a few months CHCH rf11 will be changing frequencies to rf15 on UHF so you won't have to worry about that one for long. And CKVR rf10 will be adding a new UHF transmitter that might be easier to catch than rf10 - also in the next few months.

Regardless, though, I would probably try another way of joining these two antennas.

I might use a quality two-way splitter/joiner such as the Channel Master 3212 to join the two antennas and then feed the joined antennas into your better pre-amp.

A rotator can be a pain if you're just flipping channels, but it's the greatest thing on earth when you know what you want to watch and you can turn your antenna to focus right at the appropriate transmitter.

Why not get your two mammouth antennas working together pointing in the same direction above the rotator? Digital Home member Southgate has a collection of old OTA gear including some heavier-duty older rotators that you might want to hear about. I bought my retro rotator off him.

Good luck!

mrmemario, When combining antennas after the pre-amp, the noise from the two amps are added together (effectively creating a 3dB increase in NF). OTOH, combining before the pre-amp results in signal reflections that create a 3dB loss in signal, so either way you end up with a 3dB reduction in SNR when compared to connecting the antennas individually.

On top of that, if both antennas are able to receive the same broadcast and the antennas aren't pointed in the same direction, there will be a phase mis-match (since the antennas won't be receiving the broadcast at the same time) and the combined signal will likely be less than if you only had one antenna.

mrmemario, I don't believe a combined approach will really help you. Unless you intend to place both antenna on a rotator and maintain the same direction at all times. Otherwise you take a 3dB hit, which effectively negates any benefits.

Hey guys
Thanks for all the input.
My intention was to limit the number of times that I had to rotate the newer 3671 to get the different channels and not so much to increase my dBs, although, that would have been nice. If I were to try to stack them together on the rotator, would I not still run into the same issues that roger1818 mentioned? I guess I might just look at purchasing a dual-tuner for the PC, that would work won't it?
Thanks again. Btw I enjoy the wealth of knowledge you guys sprinkle through these forums.