Sign in to follow this  
Followers 0
SqEyez12

Multiple Wisi Antenna Array Possible?

34 posts in this topic

Is it possible to have two WISI antennas at different locations on one's roof, connected, so that they act as a single array for TV reception?

The reason I ask is that I am in a fringe area (country NSW) and a signal survey across my roof could find no one location where all 5 channel groups (2,3,5,6,8) are good, there is always one or more channels that fail.

So i was thinking that if you had two locations were, say, 2,3 6 were good and a second location where 5 and 8 were good, if you could have a WISI antenna at each location and connect them in some way so they formed a single array (i.e. one antenna would not interfere with the other) then one should get good reception on all channels.

An antenna tech who did the survey today said it is not possible, but I thought I would ask here anyway.

TIA

Share this post


Link to post
Share on other sites

One thought - I would consider a second opinion & ask about the test antenna being used. The survey maybe completely correct. But depending on the antenna being used there maybe scope for a different antenna to pick up all channels from one location. In terms of what your asking above - I don't think it can be done unless the antennas are separate frequency groups - UHF/VHF or they are different polarities H/V. Which your situation doesn't sound like either of these.

In saying this I would be eager to hear from others as my understanding & installing of combined antennas has been limited to VHF with separate UHF antenna.

Edited by rapturedigital

Share this post


Link to post
Share on other sites

In some countries it is common practice to have multiple antennas on a single pole (even 4 or 5 of them) pointing in different directions, sometimes many of them are for channels in the same band. How would two antennas in different locations receiving the same frequency band be different? I know it's not as simple as that, but wanted to know the details.

Edited by Ron12

Share this post


Link to post
Share on other sites

Hi SqEyez12

This may help and in my case has been in operation on very low signals for some time now.

https://www.dropbox.com/s/a40c46xo6b9qy65/Dual%20Receive%20System%201.png?dl=0

https://www.dropbox.com/s/wm261vluaqmhlrn/Dual%20Receive%20System%202.JPG?dl=0

James

Edit (Of course the filter band pass frequency, antenna selection and polarity of antennas is to suit my purposes, you'll need to select the right filters and antennas for your system.)

Edited by James T Kirk

Share this post


Link to post
Share on other sites

Hi SqEyez12

This may help and in my case has been in operation on very low signals for some time now.

https://www.dropbox.com/s/a40c46xo6b9qy65/Dual%20Receive%20System%201.png?dl=0

https://www.dropbox.com/s/wm261vluaqmhlrn/Dual%20Receive%20System%202.JPG?dl=0

James

Edit (Of course the filter band pass frequency, antenna selection and polarity of antennas is to suit my purposes, you'll need to select the right filters and antennas for your system.)

These look like two WISI antennas but oriented at right angles, is this correct? What is the significance of the right angle orientation?

Your use of two MDA20U masthead amps is interesting, what overall gain does this achieve?

Share this post


Link to post
Share on other sites

Hi SqEyez12

These antennas are Doss UPA-4's.

The upper horizontally polarised antenna is looking at one transmission site and the lower vertically polarised antenna is looking at a completely different transmission site.

The MDA20U is a very low noise amplifier with only 19dB gain and capable of quite high output levels without producing severe intermodulation products. The filters, splitter wired in reverse and the first MDA20U are all located at the masthead to ensure the carrier to noise ratio is maintained as far as possible. This system is above the garage some 20 metres from the house and so the second MDA20U is inserted in the garage just before cable heads for the house so there is sufficient signal on arrival at the house.

In total there's about 38dB gain in the amps and 5dB loss in the filter/splitter combination resulting in about 33dB gain minus the loss up to the house.

James

Share this post


Link to post
Share on other sites

Hi SqEyz12 - Can you provide some more details about your location. You can go to Myswitch, put in your address & see if there are multiple transmission sites available. With this information you can check each transmission site, then check it's available channels then down below is technical details showing channels, frequencies & importantly each channels polarisation. If you do have several transmissions sites with different polarisation (V & H) as with James post above. Just an important point about stacking to keep in mind is to separate the antennas, maybe preventing the need for filters (Except 4G filters) - More details will help to provide you some options!!

Edited by rapturedigital

Share this post


Link to post
Share on other sites

Is it possible to have two WISI antennas at different locations on one's roof, connected, so that they act as a single array for TV reception?

The reason I ask is that I am in a fringe area (country NSW) and a signal survey across my roof could find no one location where all 5 channel groups (2,3,5,6,8) are good, there is always one or more channels that fail.

So i was thinking that if you had two locations were, say, 2,3 6 were good and a second location where 5 and 8 were good, if you could have a WISI antenna at each location and connect them in some way so they formed a single array (i.e. one antenna would not interfere with the other) then one should get good reception on all channels.

An antenna tech who did the survey today said it is not possible, but I thought I would ask here anyway.

TIA

Years ago we did some tricky things with diversity digital receivers hooked to two antennas to achieve this, haven't had any for quite some time. but if you want to experiment I'd try looking around for a dual or quad diversity receiver (quite a few made for cars). There are other ways using single channel amplifiers and tight filters fed from different antennas but you're talking $$$$ and typically only done in commercial installs

Share this post


Link to post
Share on other sites

The reason I ask is that I am in a fringe area (country NSW) and a signal survey across my roof could find no one location where all 5 channel groups (2,3,5,6,8) are good, there is always one or more channels that fail.

It helps if you post where you are.

Signal surveys should use a selection of antennas and/or masthead amplifiers at different heights & locations, not just on the roof either.

WISI antennas may not be as effective at the frequencies your local transmitter uses when compared with a narrow band yagi - again, only a proper site survey could determine this.

Share this post


Link to post
Share on other sites

It helps if you post where you are.

Signal surveys should use a selection of antennas and/or masthead amplifiers at different heights & locations, not just on the roof either.

WISI antennas may not be as effective at the frequencies your local transmitter uses when compared with a narrow band yagi - again, only a proper site survey could determine this.

I am in an obscure rural area called Martinsville, a valley surrounded by mountains and known for poor TV reception. MySwitch indicates Mt Sugarloaf as the relevant transmitter and that there is likely to be mountainous terrain intervening. However I am slightly elevated on a hill and can see Mt Sugarloaf.

How does a "site survey" differ from the rooftop signal survey that I have just had done, and what is the approximate cost?

Share this post


Link to post
Share on other sites

I am in an obscure rural area called Martinsville, a valley surrounded by mountains and known for poor TV reception. MySwitch indicates Mt Sugarloaf as the relevant transmitter and that there is likely to be mountainous terrain intervening. However I am slightly elevated on a hill and can see Mt Sugarloaf.

How does a "site survey" differ from the rooftop signal survey that I have just had done, and what is the approximate cost?

MySwitch is only an indication of possible coverage, as there can be instances where MySwitch says no coverage & that is not so, and also the opposite.

The site survey I do (if there is a reception problem) consists of testing for reception with a number of antennas/masthead amplifiers at different heights & locations all over the property. Not just the roof. This could take up to an hour before deciding if VAST is a better option.

I have mounted antennas on outbuildings, fence lines, on the ground etc if a useable signal is available, and it's possible to get a cable to the main residence without too much trouble.

The cost? I can't say for where you are, depends on what the locals charge.

Share this post


Link to post
Share on other sites

You would not install Wisi phased arrayed antenna in different locations but you would phase stack, combining two Wisi on the same mast pointing in the same direction to try and improve incoming signal for amplification. I have in the past done installations at Sandy Hollow which is far distance from Mt Sugarloaf and have used single Wisi antenna. The most critical part of those installations was the height of the antenna and it was not a case of height mean might in regards to receiving a better quality signal.

Share this post


Link to post
Share on other sites

You would not install Wisi phased arrayed antenna in different locations but you would phase stack, combining two Wisi on the same mast pointing in the same direction to try and improve incoming signal for amplification. I have in the past done installations at Sandy Hollow which is far distance from Mt Sugarloaf and have used single Wisi antenna. The most critical part of those installations was the height of the antenna and it was not a case of height mean might in regards to receiving a better quality signal.

What extra gain would you get from two WISI antennas as compared to one?

Share this post


Link to post
Share on other sites

If I remember correctly 3-4db.If you are a fair way from the transmitter and in undulating terrain the signal will be all over the place ie. some channels not all from the same location and this same result from multiple test locations. Stacking antennae basically increase signal receiving surface area of the antenna and hopefully this greater surface area captures all signals from the one location on the roof.

Share this post


Link to post
Share on other sites

Hi debruis - If I am reading you right are you creating a higher gain antenna from two same antennas phase stacked? If Yes - I am interested in your further thoughts & Info on installation requirements of Phase Stacking these antennas. Do they require specific separation distances & combining requirements eg. same length cabling to combing point? Also does this improve Signal Quality reading or just Signal Power? - Just wanting to learn more!!

Share this post


Link to post
Share on other sites

Yes that is correct. You are right about cable lengths and antennae separation. Luckly enough there is mounting hardware available that is really good for setting up these type of installations. Generally this is only minor adjustments done with a field strength meter. There are also specific stacking combiners available as well. Yes it does improve both signal strength and quality. As it is used in fringe signal area mainly you are trying increase quality and strength so you can the amplify a half decent signal and not just amplifying crap/noise. Matchmaster used to have a good diagram on their website explaining stacking while of course plugging their equipment at the same time but it is not there anymore. You might want to try Wisi site for the information. I hope this has been some help.

Share this post


Link to post
Share on other sites

The fracarro phased array is a good suggestion. James has suggested the mda20u I can verify that their range on amplifiers works where nothing else has. It may be worth seeing if anyone on the forum covers your area. I use a unaohm ap01 as a meter and the number of times I've done a job where 3 other guys couldn't get results and didn't know what a spectrum analyzer is our how to use one is bewildering. A good meter and technician is obviously crucial. I recommend in weak signal areas to only add filtering as absolutely necessary. The narrow band Yagi's that fracarro make do amazing things. Some of the new wisis have a LTE filter inbuilt which brings

Share this post


Link to post
Share on other sites
On 21/12/2015 at 10:44 PM, SqEyez12 said:

Is it possible to have two WISI antennas at different locations on one's roof, connected, so that they act as a single array for TV reception?

The reason I ask is that I am in a fringe area (country NSW) and a signal survey across my roof could find no one location where all 5 channel groups (2,3,5,6,8) are good, there is always one or more channels that fail.

So i was thinking that if you had two locations were, say, 2,3 6 were good and a second location where 5 and 8 were good, if you could have a WISI antenna at each location and connect them in some way so they formed a single array (i.e. one antenna would not interfere with the other) then one should get good reception on all channels.

An antenna tech who did the survey today said it is not possible, but I thought I would ask here anyway.

TIA

You can couple them with a 2 way splitter in reverse.

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!


Register a new account

Sign in

Already have an account? Sign in here.


Sign In Now
Sign in to follow this  
Followers 0



  • Similar Content

    • By BelindaMaree
      Please help?
      I have attached the pic so you can see what I'm after 
      please help 

    • By vanderblitz
      Hello,
      I'm looking for a reputable TV antenna installer for a new single story house, with colorbond roof in Williams Landing suburb (west of Melbourne)
      Any recommendations?
       
      Thanks
       
    • By prashant75
      Hi there,
      I am not very expert in TV technology and i really need your advice. I have a Samsung Smart TV 7 series (bought in Dubai) and i am not able to get Free-to-Air Channels. I dont have any STB and no pay tv like Foxtel etc. I am not a big TV buff but want to watch free channels. I tried to setup using auto-tune and manual tune, but no luck. Also, there is something called "Area/Region" for setting channel in TV and i dont have "Australia" option in the list. I live in an apartment and each unit has a point to connect. Most of the people in my building are receving good signal and able to watch free channels.
      I called Samsung support and they said my tv doesn't has/support Australia frequency. They advised me to check with local retail shops or buy new TV.
      I dont want to buy new tv. does it work if i buy a Set up box such as Dick Smith HD Digital Set Top Box with USB PVR.
      I really need your advice.
      Thanks in advance.
      Pras
    • By Dexx
      I have a TV in a room where an external antenna connection isnt possible. Can you recommend a cheap indoor antenna which works ok in a medium signal area? VHF primarily.
    • By calichin
      Hi,
      recently moved to a new house in the eastern suburbs of melbourne. The house has an external antenna and I assume it was working for the previous owner. When I plug the TV directly to the wall socket, I get ~8-9% of signal strength on the TV (did I mentioned the antenna is on the roof?). When I plug the PVR to the wall socket (and then the TV through HDMI) I get no signal at all. The "passthrough" of the PVR also gives no signal to the TV. With the 8-9% I can watch some TV, but I get a lot of freezing. Interestingly, I plug an old "rabbit" antenna to the TV or the PVR and I get ~50% of signal strength.
      I'm trying to sort out where the issue could be. I have:
      confirmed that the wall socket is connected (behind the plate)
      the cable runs to the roof
      the cables in the roof are connected to the antenna.
      I should give a bit more info:
      there's one cable coming down from the antenna and then there's a splitter (a simple small one maybe 2cm x2cm): 1 in, 2 out.
      one of those "out" goes into a room but I don't have a spare tv to test, and moving the large tv is not an option.
      the other out goes to another splitter, but this has some sort of circuit board. there's no splitting happening as there's only one in and one out (but more out could be used). Then after this second splitter, there's a third one similar to the previous, a small box where one comes in and 2 comes out, also with some sort of electronics in there.
      There's only 1 tv in all the house, if there are other TV sockets, they aren't used.
      I've gone as far as I can understand, so I came here for help. Should I eliminate all the extra splitters? replace them with new ones (looks a bit old and dusty)? is it worth buying one of those antenna meters to test the signal strength?
      (like this: http://www.jaycar.com.au/productView.asp?ID=LT3332)
      I haven't climbed to the roof yet. Is there some sort of connector at the roof that might be loose? I'm trying to figure out if the issue could be somewhere else before adventuring to the roof.
      Any help or suggestion would be greatly appreciated.
    • By uanmi
      Hi,
      I have a TV antenna and above it is an old antenna that has broken and part is hanging down onto the other antenna. On a windy day they bang together and this causes dropouts.
      I would like to also get two more tv points in two rooms that don't currently have TV points.
      I have been using an indoor antenna in one room and it does not get channel 1, 10, etc. This is quite frustrating as I enjoy some of the shows on that channel.
      I would apppreciate an indication of what the cost would be.
      regards, Mark
    • By Matthew Bongiolatti
      Hey guys,
      After cancelling foxtel due to not really watching the channels apart from free to air, i found that i was missing having the ability to record tv, so being new to HDTV recorders i did alot of research into which system suited me best. I settled on a Topfield TRF7160 and bought one for a great price at JB HiFi.
      Went to install the new PVR and this is when the strange issues occured. This is what i did:
      Unplugged the coax from the tv and plugged into the antenna in port of the pvr.
      Plugged in HDMI, TOSLINK, ethernet & power in. All Ok
      Turned on tv & pvr, went through the setup scan of channels to which the unit found none. Puzzled, as my HD TV with in builtin HD tuner works perfectly fine, i started to fiddle with the cable. After no more luck, i came to the conclusion that somehow my existing cheap coax cable was faulty and bought a new $40 one from Jb HiFi. No luck.
      I then plugged in a portable powered rabbits ears that i use in the spare room (which works ok), and ran the scan again. The toppy picked up SBS stations but nothing else, tested the channels to which were working. I then plugged the wall coax back in and found that is lost signal straight away. Plugged it directly back into the TV which worked fine on all channels.
      Thinking that there may be something strange going on with the coax port on the toppy, i loosely plugged it back into the toppy and i started to get a picture.. I then ran the toppy through a channel scan again and it found all channels with 90+ reception.
      At this point i settled on there must be something wrong with the unit and returned it to JB. Brought new one home today and same problem exists.. I have found that as long as the coax cable is loosely touching (or even not touching by around 2-3mm) the signal is perfect.
      I have no idea why this is happening but was wondering whether anyone had any ideas, as the way it is set up now is not ideal?
      Cheers in advance and apologies for the essay, but i thought as much info that i can give will help.
  • Recently Browsing

    No registered users viewing this page.