Mounting a antenna question

[Kane84]

Need to know if you can mount two antennas on the same pole if so how much space should I leave between them if I can't do that then how far apart should I have two antennas on each of their own pole.if this helps I have a digiwave Ant 5011 and a digiwave Ant 5006.right now I have the ant 5006 up which is only uhf aimed at toronto and the 5011 is VHF, UHF I don't know what one I should be using for toronto and then whatever one for a second signal any help is appreciated and here is my tvfool report

http://www.tvfool.com/?option=com_wrapper&Itemid=29&q=id%3d2c15fc3182dfc9

[jvvh5897]

You can put two on the same pole--space them farther apart than the lowest wavelength that you want to get. If they are pointed in radically different directions then the space will be less important. Think a meter or two if you don't use the low VHF channels 2-6

[Kane84]

the pole is about 7 and a half feet with my Ant 5006 at the top or should I put that at the bottom being a smaller antenna and put the ant 5011 at the top giving more of a space

and which antenna one should I use for Toronto with giving those two antennas,because I am looking to aim at another tower and the one antenna 5011 is a est.140kms and the other doesn't say from when I've tried searching for it online

[Kane84]

Well I'm in a apartment on the third floor facing Lake Ontario with the escarpment behind me I want to try getting the grand island,NY tower or the Rochester,NY tower from my location to grand island is roughly 76kms and rochester NY is 181kms from my location according to this other website xtek.so my ant-5006 where I can't get the range of it because it shows NA I want to use for either one and my ant 5011 for Toronto since that's only 140kms in range

[Terryl]

Use the link below it will give you an idea on whats going on with the stations around you.


www.tvfool.com

Mounting two different types of antennas on the same mast can get tricky, in some cases they will not affect each other, all systems are different.

Co-phasing them is the fun part, if the two antennas have different gain specifications and different side lobes they can cause hair loss and use of words that small children should not hear.

TV channel 7 (bottom channel in the VHF high band) has a frequency of 174 MHz, this gives you a wave length of 67.8 inches, TV channel 14 (bottom end of the UHF band) has a wave length of 25.12 inches.

So if your using two VHF/UHF antennas the you need to space them (top to bottom) at least 68 inches apart, if using one VHF/UHF and a single UHF antenna then the minimum spacing would be 25 inches.

The coax coming from both antennas should be exactly the same type and length, minimum length for two VHF/UHF antennas would be 68 inches, minimum for a UHF/VHF/UHF combo would be the same, a UHF/UHF combo will be 25 inches.

For longer runs multiples of the above need to be used, after one full wavelength you can use 1/2 and 1/4 wavelengths, there are formulas for exact cuts if you not using a special combiner for the above.

Here is some good info on the co-phasing.


http://www.kyes.com/antenna/stackluge.html

[Terryl]

On some co-phasing arrays we had to use some shielding, a Faraday shield was used to keep the antennas from cross talking.

But this was for some big MATV setups, big money in those.

[Kane84]

Ok well I'll try mounting both on the same pole then if that doesn't work I'll have to use the other pole I have and try the antenna off that roughly if anyone can say what's the true north degree for those two signals

[Kane84]

Is it the numbers on the right hand side under azimuth true and magn and I go by true if that's correct

[Terryl]

If you using an uncorrected compass then you use the magnetic, if the compass (or GPS) is corrected for your location then use the true.

Almost all locations have a magnetic offset, (some don't) this is called "Magnetic Declination" this can range from plus or minus 1 to 20 degrees, it all depends on where your located, and this changes over time as the magnetic North and South poles drift, one of these years (many many years) the poles with swap places.

If you using a compass then look here for the correction factor at your location.

http://www.magnetic-declination.com/

[Kane84]

I'll be using my compass off my phone

[Kane84]

I got close to my area as possible and this is what I got from that site
Latitude: 43° 13' 51" N
Longitude: 79° 48' 42.3" W
Magnetic declination: -10° 5'
Declination is NEGATIVE (WEST)
Inclination: 69° 39'
Magnetic field strength: 53972.8 nT

[Kane84]

Ya the iphone does both

[Kane84]

And couldn't I use a pre amplifier for the signals I am trying to catch from NY with them being weaker

[Kane84]

Ok now when I pick one up would this pre amplifier be attached before a diplexer or after

[Terryl]

You have a diplexer in this system??

Are you using it in a satellite/OTA signal on the same coax?

If so then the pre-amp will not work, it needs it's own DC power supply, so a pre-amp is out, you would have to run a separate coax to the TV antenna/pre-amp then down to the TV it's self.

Or the DC power supply for the pre-amp would have to go after the last diplexer.

The use of diplexers adds signal loss to the system, this may be why you are having some weak signal problems.

[Kane84]

what I want is to catch both Toronto and a New York signal using both my antenna's the digiwave 5006 and the digiwave 5011 they both have amplifiers already with them and from what I was told is that when your going with two signals you need a diplexer and a tv splitter to run it to how many tvs your going with

I'm only using OTA Signals don't have sat or cable

And I haven't added the diplexer yet right now its only one OTA antenna up and running that is the Toronto signal I've ran it to my 1 in to 3 out tv splitter that has one antenna in and three out I've used 1 out so far

[Kane84]

and I was only asking if the pre amplifier would work I wasn't picking one up until I researched if it would help or not

[Kane84]

2339323394


thats what I have so far thats hitting toronto so please guide me on how to get my other antenna up and running catch a new york signal that antenna has a amplifer on it my cable running from that one is hooked up to my living room tv with a 1 in 3 out splitter already using it for my living room tv my other antenna has a ampifier also now like someone posted before about mounting it on the same pole but have so many feet in between each antenna I don't think I can it will have to be done on another pole and further away from that one unless I measure 6 feet apart and then put both poles and antennas up thats about 24 feet height I have on my side

[Terryl]

Ok, heres what needs to be done, your going to have problems combining two different antennas into one coax, you need a special combiner to do it right, it can be done with some special instructions and exactly the same setups.

The best way to do this is the run two seperate systems, then use A/B switches to go between the two, this will save you the heartache and hair loss of trying to co-phase two TV antennas to make it work without problems.

To set this up right, use two TV antenna with pre-amps, two 3 way splitters, two separate runs of coax from the antennas (one each) and A/B switches at each TV that needs to use the two setup's.

The DC power supply's for the pre-amps need to go on the DC path side of the 3 way splitters.

Now the 3 way splitters will attenuate the signals by about 9 dB, this is 1/4th of the signal to each TV set, you loose 1/2 of your signal with each 6 dB of signal loss.

Example: Say the signal is at -100 dBuV, (or 100 mV) deduct 3 dB and it drops to -103 dBuV (70.7 mV ) deduct another 3 dB and its at -106 dBuV (50.12 mV) deduct another 3 dB and your now down to -109 dBuV (35 mV), this is the signal going to each TV set.

So if you add up your losses, the coax then splitters and A/B switches you then deduct this from the gain of the antenna and pre-amps, if your gains out weight equals your losses then the system should work.

[Kane84]

There is no other way of doing this I really didn't want to be using a a/b switch that's all