Yes, 'have noticed that. But I’m not sure, if the N-BNC-adapter or the BNC-plug of the antenna cable are really good sealed from water ingress or snow & ice in winter …
For a nice DIY-‘radome’ look also here ==> http://discussions.flightaware.com/ads-b-flight-tracking-f21/shorting-a-spider-antenna-t35565.html …
… anyway, the 5/8 antenna looks some more ‘professional’ 8)
.
How many people have trouble due to rain & snow, in their roof top TV antenna \ Dish antenna?
https://farm8.staticflickr.com/7546/16105514307_1cb8763088_o.jpg
That’s what I mean, to be sure, that cable & connector are protected, I would recommend to apply self-fusing tape 
… I used some it for the cable entry of my ‘interim solution’ (RasPi in a PET bottle) 
darethehair uses the same 5/8 antenna; look at 2nd pic 
==> http://discussions.flightaware.com/post187235.html#p187235
I grabbed one of these as well and concluded that is was a fairly inexpensive source of solderable coax with a nice connector on the end 
I had the antenna ~0.5m up a plastic pole on top of my garage. Did ok picking up local planes, range was very low. Ended up cutting the antenna off and soldering the cable to a new Franklin I built on the weekend. That is doing not too bad so far. (flightaware.com/adsb/stats/user/ehud42)
@ehud42:
I also discovered the same thing. Please see this thread:
Trial Run Results for Three Types of Whip Antennas
Another related thread you may find interesting:
Hi all,
New to the whole ADS-B tracking here. I’ve got myself set up with a raspberry pi and regular old DVB-T dongle. It’s working well, but I’m only getting about 30NM-50NM coverage at the moment.
I’m looking at creating a Cantenna or Spider antenna. Which one do people generally get more range with? Also, for the Spider antenna, what gauge of copper wire to people use for the legs and whip?
Thanks 
The Cantenna has my vote, The wire diameter does not matter, but I used a paperclip which is nice and strong and can cope with any passing pigeon.
I have tried several commercial antenna and the Cantenna is superb value for money and a nice no risk starter.
One day I shall be brave and build a collinear
Location, and height (clear view of horizon), out weigh the antenna and everything else!
Thank you . Going to assemble one today. Does it matter what sort of can I use? I’m thinking about an empty soup can?
Out of curiosity, I see people showing their range on maps. How does one go about doing this?
@cs777
I am using my retired RPi B+ for testing software. It is located in a room where signal is not as good as where my main receiver and Cantenna are located.
For my test receiver’s antenna, I made a Cantenna with an un-cut food-can (easier, no cutting of cylinderical wall, only drilling a hole in the bottom).
The food can is 2-11/16 inches dia x 3 inches height (7 US fl. oz).
In metric units, it is about 68mm dia x 76mm height (205 mL). If measured with rims, it is about 70mm dia x 80 mm height.
Every antenna’s performance heavily depends on its location. I therefore cannot say how the un-cut food-can Cantenna compares with optimally-cut drink-can Cantenna. Since the Cantenna is very tolerant to dimensional variations, I feel the difference will be slight.
This weekend I will replace the drink-can Cantenna of my main receiver by food-can Cantenna to find out the difference.
The earlier comments about the advisability of starting out with a simple home brew antenna design is of course correct, but it is not hard to make a vastly superior collinear out of TV or satellite coax by following the easy instructions shown in this video.
The main pitfall in this design is to make sure you have the correct velocity factor worked out by checking what kind of central insulator your coax has. Mine had a foam insulator so I used 98mm long elements. If it had been solid plastic insulator and not foam I would have needed 110mm. These given lengths are teh length of the uncut coax, not the connecting stubs of the central conductor.
I slid my eight element collinear (all sections simply taped together with insulating tape) into a length of cheap, black electrical conduit with a wine cork stuck in the top end to seal it, taped around the cork and around teh base of the antenna and poked it out of my roof. I regularly get 300 statute mile spots and many hundreds a day of spots over 250 miles.
flightaware.com/adsb/stats/user … tats-27881
I am using the excellent Flight Aware dongle and filter with a short RF cable (about three meters) and a long USB lead. Both the Flight Aware filter/dongle and this antenna make a huge difference over my earlier R820 / 1/4 wave spider antennas. I tested the collinear mounted in the same position with the same length feeder against a carefully made spider antenna and I gained about a third more range.
Watch the video - it isn’t rocket science. Good luck. This antenna including the plastic conduit tube to protect it from weather cost me about £3 in total.
Making an inexpensive 1090MHz ADS-B collinear antenna - YouTube)
@volpoon
Great! You are amongst the very few lucky ones who get their Coco right.
All Collinears (Coaxial, Wire, PCB etc) are easy to make, but hard to get right without:
(a) using correct VF
(b) precision of cutting & assembling
(c) proper (and costly) test equipment and
(d) technical know-how to use these equipment to tune an antenna.
Since the normal hobbyist lacks last two of these requirements (c & d), most end up in a poor collinear antenna (Coaxial, Wire, or PCB). Only a few lucky ones like you end up with a comparatively better one, a shot in dark which luckily hit the target board, but definitely not the bulls-eye.
ignore points c&d have a go. Whats the worse that can happen?
@theresjam
Worst which can happen is a lot of frustration when you try your new coco and find it performs much less than a 1/4 wavelength groundplane (Spider or Cantenna).
No harm in trying. If one is lucky, his coco will perform better than Spider. If unlucky, his frustration will be a lot less if one is aware that the chances of ending up with a poor coco are high.
I don’t understand your scepticism. I’ve made a fair few antennas for ADS-B over the last four yeas since I started dabbling. They have all cost me pennies to make, some worked quite well and I could ‘see’ planes 200 miles off, some were really poor and couldn’t ‘see’ more than about fifty or sixty miles. The video I referenced covers pretty much all you need to know to make a great success. A pal of mine a hundred miles away also made one - we both found stark improvements over our spiders. You are absolutely correct about getting Velocity Factor right, but this is usually available in the coax specs. And anyway - any antenna dabbler needs to consider velocity factor in putting up an antenna of whatever type, even if it is an HF dipole for the forty metre band. If the wire is covered by insulation, the VF will be different. It is frankly not true to say you NEED complex test equipment. Simple mental arithmetic and cable of a known VF is all that you need besides an accurate ruler and a sharp knife.
The point you made about accurate measurement and assembly applies equally to a 1/4 wave whip. This is especially true at these high UHF frequencies - HF - not so much, because minor errors then become a tiny fraction of a wavelength.
The signal collecting capacity of eight or twelve properly cut, half wave antennas stacked i correct phase is significantly more than a quarter wave - to say otherwise is frankly far from reality… My collinear is an eight element one. It took me an hour to knock up including climbing about in the loft and poking it out of the roof. The coax was lying around as an off-cut so it cost nothing, the electrician’s conduit tube cost £0.99 and is twice as long as it need have been and I am seeing about 1300 to 1500 planes a day at over 250 miles.
I am experimenting with two old net-book computers so I have two feed pages on Flight Aware. The current one is here:
flightaware.com/adsb/stats/user … tats-26363
In a few days time from now, my page will be here:
flightaware.com/adsb/stats/user … tats-27881
I would also say that this antenna was easier to make than my several spiders since it has no soldered joints. Correctly dimensioned collinear antennas will ALWAYS knock spots off a quarter wave whip… It is a simple matter of physics. Look in any antenna hand book. The VF of the cable MUST be known or carefully estimated. Mine had a spongy central insulator core so I used a factor of 0.8. If it is hard polythene then use 0.66. The calculation is detailed in the video.
I returned my 49", FlightAware antenna to Amazon because my stats started falling off vs the, shorter, 24" FA antenna.
Will attempt to construct an 8 segment col-linear as described in the YouTube video and report back.
Calling me a novice would be an understatement. 
If you look at the title of this thread, it says “…for Beginners”, and that is why only 1/4 wave ground plane (Spider & Cantenna) were presented.
The 8 elements stacked vertically in a collinear fashion, will give higher gain and a better radiation curve, but can it be made successfully by a beginner without prior experience in making, tuning & using antennas? Chances of making a successful collinear (wire/coax/stripline) for a beginner are slim.
On the other hand for persons with prior experience of making & using antennas on HF, VHF & UHF, chances of success are much better.
The best strategy for a beginner is to start with a sure antenna like Spider & Cantenna. Once his system is up and running, he can navigate the troubled waters of collinears. One should first learn to walk before trying to run.
It is worth experimenting with coco, but with awareness that chances of success are not bright. This awareness will help in reducing frustration if failed.
Given that the segments are correctly measured, the main potential for failure is short circuit caused by whiskers of braid connecting across the ends of the elements. CAREFULLY inspect each end of every element for whiskers of fine copper braid before connecting them. They are very easy to miss, so don’t rush the inspection. DON’T forget the tape across the ends to additionally assist in preventing a short at every joint. Push the elements together and if you have a continuity tester, or a simple multi meter, check each connection for continuity and shorts as you add each element, checking from the feeder end. The central core of the feeder will be connected to the end of each new element either at the braid OR the central core wire, alternating as you build it up with each new element. Likewise the screen of the feeder will also be connected to either the braid OR the core of each new element at its far end, but in the opposite phase to the centre of the feeder. Check each time that the feeder central core is NOT CONNECTED TO BOTH core AND braid on any element. The central conductor can only be connected EITHER to the core OR the braid. Same with the feeder braid. As you are building it up, if you find ANY connection to both on a particular element, you have a short and need to look at that last joint you made before you go further. If all is good, tape the new joint tightly and move on to the next. Give each joint a good wrapping of tape to ensure a long lasting antenna.
Eight elements will give a huge gain over a quarter wave. It will have sixteen times the signal collecting capacity because it is sixteen times as long.
Try it. All you have to lose is an hour and less than five dollars or about three UK pounds and only that much if you enclose it in electrical conduit (plastic obviously not metal). If you can fit a coaxial plug, and can use a ruler accurately, you can make an eight element collinear that will beat any other omni directional antenna by miles - probably by a hundred miles if you have a good site with all round to the horizon visibility.
Like any antenna, especially at these high UHF borderline microwave frequencies, it must be high and in the clear to give good range. If you have a good site, it will deliver the maximum theoretical range possible before the planes drop below the horizon.
Collinears not only have more signal collecting capacity than a quarter wave, but a much lower angle of radiation. Quarter wave antennas have their strongest radiation (and reception) at an angle bisecting the angle between the ground planes and the radiating element. A collinear looks straight out flat to the horizon, but will still pick up aircraft over flying your location.
