best antenna

[abcd567]

Hi again ABCD567

After a couple of weeks use I can see that my installation is about as good as I could expect. I may still replace my coax colinear (This design but joints pushed together rather than soldered :- http://www.rason.org/Projects/collant/collant.htm ) with one that has soldered joints and uses lower loss coax (just using cheap Chinese RG59 at the moment)
Using an on-line calculator to work out what distance an aircraft at a particular height goes behind the horizon from my location (which is 790 feet above see level) I find that at 37,000 feet it works out as 236nm and even at 41,000 feet it is only 246nm. As the maximum I'm getting regularly 248 - 252nm I can't see that making any changes is going to result in much improvement.
What brings me back here are your polar plots which appear to be on a Virtual Radar map like the one I'm using. I've gone through the settings page and have set the the range rings to various settings but I'm curious as to how you have got the 24 hour plot. Is it hidden in the settings of Virtual Radar somewhere or are you using some other software?

On VRS application window (NOT on the Google Map in Browser), click Tools > Reset receiver range plot > your-receiver-name
This will clear the previous data, and start range plotting afresh. After this , whenever you open the Map in the browser,, it will show range plotted from the time you have reset the range plot, till now. You see Map in browser 24 hrs after resetting, the map will show 24 hrs plot.

VRS Range Plot Reset.PNG

[abcd567]

Dipole Gain & SWR vs Length of it's Limbs
Theory says SWR=1 when each limb is 1/4 wavelength (68mm)
Simulation shows SWR=1 when each limb is few mm less than 1/4 wavelength (63mm)!!
Which one to believe???
I will have to test this by making a dipole with 68mm each limb.
Then VRS range plot for 24hrs, trim 2mm, VRS range plot again for 24hrs, trim another 2mm, test again for 24hrs.
This is driving me crazy.

dipole vs length.jpg

[MatthewE]

Anyone have any idea at how effective COCO Omnidirectional antenna's are inside the attic/loft? I only have roof tiles, the bare minimum up there so I don't think there would be many things blocking it, I could mount it within the garden however it wouldn't be very high and I'd have to figure a way to route the cable through into indoors.

[fungus]

Anyone have any idea at how effective COCO Omnidirectional antenna's are inside the attic/loft? I only have roof tiles, the bare minimum up there so I don't think there would be many things blocking it, I could mount it within the garden however it wouldn't be very high and I'd have to figure a way to route the cable through into indoors.

MattewE;

I can only speak for here in Australia but most roofing tiles are made from either cement or terra-cotta and probably wouldn't be good for any antenna signal. That's one reason why one has to get an external antenna above the roof line of your own premises and those around you. Also many homes have the aluminium sisal or the like, let alone all the timber or other construction material which could likely block signal altogether.

Regards,
Gregg

[Yxespotter]

Anyone have any idea at how effective COCO Omnidirectional antenna's are inside the attic/loft? I only have roof tiles, the bare minimum up there so I don't think there would be many things blocking it, I could mount it within the garden however it wouldn't be very high and I'd have to figure a way to route the cable through into indoors.

I had hoped to have my homemade coco mounted outside on the roof before winter, but alas, the snow fell early this year and it needs to wait until spring. In the meantime, it's mounted indoors against a second floor indoor balcony. Above is the wooden attic structure with asphalt/ground-stone shingles, and I'm regularly getting 350-400 kms with occasional spikes of greater distances.

This may not be relevant in your area, however I found that the snow depth on the roof does make a difference to reception especially once it ages and packs itself into ice. Two feet of fresh fluffy snow does not appear to affect the signal significantly, but after it packs down to a few inches of hard snow and ice, reception is reduced by about 75-100 kms until the ice clears.

The extra indoor time has allowed for some additional tweaks to improve reception.
These are my January results - red rings are 100kms apart. To the north-east is the thickest buildup of snow-pack on the roof.

January.jpg

[trigger]

@MatthewE

I did all my antenna testing in the loft. I have cement tiles and found I got an extra 20nm once the antenna went outside. When you have something that works well, start thinking about how you would get it outside. Your location will ultimately decide your maximum range and "hits".

[delcomp]

The old saying we have is... :

The Higher the better...!

[fungus]

The old saying we have is... :

The Higher the better...!

Absolutely agree mate, .... until things go wrong. The SSE 1090SJ that you gave me has failed (could be the amp- the injector has tested ok as it's here inside the house) and I need to test and check the amp- on the 30' mast atop the ridge capping installed by the professional TV guys. Looks like the cockies, corellas and galahs have been busy 'enjoying' chewing my setup. The 'boss' wont let me climb up on the roof so I'm not too sure how I'm going to proceed from here (don't want another spell in hospital). So for now I'm back on the Discone with limited range. At least it keeps me out of the boss's hair for a while sorting it out.

Regards,
... and there'll be an answer to it somewhere, sometime I'm sure,
Gregg

[CanadaKen]

So....getting back to the original post 224 pages ago.

What are the top rated 2 or 3 ADS-B antennas right now? I have moved and do not have the space
for homebrew so they will need to be store (web) bought.

Thanks
Ken

[fungus]

So....getting back to the original post 224 pages ago.

What are the top rated 2 or 3 ADS-B antennas right now? I have moved and do not have the space
for homebrew so they will need to be store (web) bought.

Thanks
Ken

Ken,

As I indicated in my last post forget a Discone as it's a broad frequency spectrum antenna not designed specifically fo ADS-B, whereas the SSJ 1090 is and you'd get far more range. As mentioned both on this and other threads it is discontinued but if you search you'll find links to antennas designed for ADS-B which are currently available. The type of receiver you have can also have a bearing on what best suits your situation. There is a thread for best purchased antennas (current) so I'll post the link when I can find it.

It's also important to match the amplifier (if used) to the antenna. With my setup I cant use the same amp with the Discone as I can with the SSJ1090 and vice-versa and expect the same results due to the SSJ having a DC bridge whereas the Discone doesn't.

http://forum.flightradar24.com/threa...(for-purchase)

Regards,
Gregg

[Scroggie]

Thanks for that, I can't believe my own stupidity! I simply hadn't ticked the receiver range options in the map menu!
Here is a 72 hour plot.
Circles are 90 nm intervals so I'm happy with this - the radio line-of-sight distance to the East for aircraft at 40,000 feet is around 250 nm so I'm not going to improve on this whatever I do. I calculate that to get the same range to the west my antenna would have to go up another 250 feet or so to see over the hills.
Many thanks for all your patience and help.
Range.jpg

[abcd567]

........Here is a 72 hour plot.
Circles are 90 nm intervals so I'm happy with this - the radio line-of-sight distance to the East for aircraft at 40,000 feet is around 250 nm so I'm not going to improve on this whatever I do......
[ATTACH=CONFIG]5653[/ATTACH]

Great, good coverage. Congratulations.

[toString]

Thanks for that, I can't believe my own stupidity! I simply hadn't ticked the receiver range options in the map menu!
Here is a 72 hour plot.
Circles are 90 nm intervals so I'm happy with this - the radio line-of-sight distance to the East for aircraft at 40,000 feet is around 250 nm so I'm not going to improve on this whatever I do. I calculate that to get the same range to the west my antenna would have to go up another 250 feet or so to see over the hills.
Many thanks for all your patience and help.
[ATTACH=CONFIG]5653[/ATTACH]

Good god! Got any pictures of your antenna/mast/array

[abcd567]

THE SPLIT CANTENNA - A HYBRID OF CANTENNA & SPIDER

New concept, not yet put to trial run.
24-hrs trial run & VRS Range plot yet to be done

THE SPLIT CANTENNA
DSC03535-R.JPG . DSC03537-R.JPG . DSC03539-R.JPG


ORIGINAL CANTENNA
Cantenna.jpg

[1090 MHz]

How about these new 222ml coke cans that have hit the market? ... seems Coke might be phasing out the 355ml cans in favor of them but keeping the price the same

http://time.com/money/3667808/mini-c...d-value-price/