Built my first antenna and doubled my coverage

Looks good. The spider type antenna has worked best for me, followed by the cantenna.

IF… I understand you correctly, the IP address is the address that appears on “My ADS-B” page?

If so, once I know this how do I access it?

Thanks!!!

STEP 1: From Flight Aware’s “My ADS-B” page (or from your Router’s settings), find your RPi’s IP on your Local Network.
https://c1.staticflickr.com/1/550/19229525111_dc619c1db4_o.png

STEP 2: Start puTTY, you will get this window:

STEP 3: Type (or copy paste) your RPi’s IP and click “open” button. This will open a Command Window

STEP 4: On the Command Window, type your RPi’s Name & Password, and you will login.
After login, you can give any command to your RPi. For example if you want to reboot RPi, type “sudo reboot” and press Enter button on your keyboard. To shutdown, type “sudo shutdown -h now” and press Enter button on your keyboard (If you shutdown, then to restart, you will have to unplug and replug the power to RPi)

Putting the antenna outside will make a huge difference, above roof level, above the level of other obstructions (chimneys, etc)

do just put a bead of silicon caulk at the base of vertical whip antenna to ensure rain water will run off rather than puddle on the connector

do attach the PV amp directly to the base of the spider and run up to 10m of RG6 or similar coaxial to the rest of the gear (power inserter, filter, pi) that is somewhere cool

do wrap the amplifier and connectors in self amalgamating tape (3M Rubber Splicing Tape) - see Amalgamating, self-fusing tape [Handyman Demos] - YouTube) (also consider to see if you can shade the amplifier from direct sun-heat - maybe slip a loose fit plastic tube over it - cable tie loosely to prevent it sliding away)

don’t worry over much signal loss in the down lead - the amplifier will more than compensate.

It may be worth providing a grounding wire from the outer of the coaxial cable - so if you get static build up on the antenna it has somewhere to go … otherwise it tends to take out the Ethernet port on the Pi

(by the way, I stopped overclocking the Pi - it was crashing too often)

It looks like the new 8-legged Spider is already producing reduced results. The range has dropped by about 50 miles and I am not getting ground traffic at KORD. The Cantenna definitely has better results.

Marty

A Possible Filter???

Two whips, 1/4 wavelength (69 mm), at a spacing of about 1 inch (25 mm), enclosed inside a drink can.

https://farm1.staticflickr.com/382/19056047500_e70e64498b.jpg

https://farm1.staticflickr.com/431/19056080338_b0ec120bf9.jpg

https://farm4.staticflickr.com/3948/19243673105_f911cd68d8.jpg

Looks promising. Would be nice to see the before and after screen shots with the same resolution. The ones you posted have the #1 with about -7 to -11 and #2 with about -10 to -20.

…Tom

The rtl_power panorama I used to plot frequency vs power (dB) curve, has no provision to adjust resolution by the user. It automatically selects the resolution.

Thank you, it still looks promising, I will try one myself.
…Tom

Built one using a soup can and two BNC bulk-head fittings placed 25mm apart with 69mm whips. It is installed between a Perfect Vision amp and the dongle on site #8130.

http://flightaware.com/adsb/stats/user/tjowen#stats-8130

Will try and get a photo posted soon.

…Tom

What happens if you uncheck “Auto dB” at the top of the app window?

About an hour ago, I tried to plot the frequency vs power (dB) curve with “Auto dB” unchecked, and found that my Noise Source is not giving any output.

I have purchased the Noise Source from eBay for $22 and got it only few days ago from China after 1 month shipping wait.

Right from beginning, it used to be burning hot, but was working OK.

Today when I powered it ON, I found that although the green Power LED is lighting, it is no more giving output, and it is warm only, not burning hot like before.

My deceased noise source :cry:
https://c1.staticflickr.com/1/311/19305692561_26cdc05ec4_z.jpg

Hi
I’ve just made my 4’th COCO, and this seems to work :smiley:
Has anyone tried to put groundplane/radials on one of these, I was wondering if it would have a positive effect on the antenna.

As a class of dipole antenna, one if the benefits of the collinear array is that it doesn’t need a ground plane or radials. Most likely you’d screw up the radiation pattern unless you had them mounted at the right electrical distance from the dipole array so they’d be electrically useless.

bob k6rtm

Hi Bob & Hi Xroads
I have made 6 CoCos. The 6th is better than other 5, a reasonable one, not very good one. I used cheap RG6 Coax purchased from a “dollar shop” - a 75ft coil for $7.50. The VF is unknown as the manufacturer is unknown. Since various makes of RG6 have VF in the range 0.8 ~ 0.85, I made 7 Cocos, each having length of element based on VF 0.8, 0.81, 0.82, 0.83, 0.84, & 0.85. The one which gave me reasonable results has element lent = 11.4 mm i.e. VF= 0.83.

I have made 7th CoCo also, but it is of non-conventional design. The element length was calculated using formula:

Element Length = halfwavelength x 2xVF/(1+VF).

It’s element length was 125 mm based on VF=0.83. In this design, the sum of Electrical lengths of each pair of electrically connected adjacent shield (radiating element) & core (phasing element) is exactly equal to one wavelength, a perfect phasing condition.

Theoretically, this arrangement should give much higher Gain than conventional CoCo made of “VF x halfwavelength” elements. However upon trial run, it was not found so. It seems this arrangement has a much higher SWR, which almost nullifies the advantage of High Gain. To overcome this situation, an impedance matching arrangement may be necessary, such as a matching T or Pi network, or transformer, or a 1/4 wave shorted stub at top, etc etc.

Hi Bob!
You are right. CoCo is actually a Collinear Dipole with BOTH limbs pointing up from the feed point, contrary to conventional dipole which has two limbs pointing in oppposite directions from the feed point.

Below is a diagram explaining how coco works. Technically, this diagram is not strictly accurate. I have made it like this to make it easy to understand and grasp the underlying principle of CoCo, as most of hobbyist are not proficient in electrical theory.

Hi Bob and abcd
Thanks for your replies and abcd as allways a very good explanation.
Unfortunately it was not as good as expected, so it’s going down again, and my wire collinear is going up again.
The coco is giving me app. 50km less range than the collinear.

https://db.tt/ooczYWtt

Regds
Max

It will be nice if you post a sketch of your wire collinear with dimensions of vertical sections, coils and radials.

Hi

It’s not my own design, one I’ve found on the net.
I constructed it a bit different, as instead of doing it in one piece, I’ve made all the sections separate and finally soldered them together.
In this way it’s much simpler to get all the measurements exactly correct. And the antenna is working a treat, tracking planes out to 200nm.
I’m using a lna very close to the antenna and a 1090 filter after that, only having a total coax run of app. 6m
https://db.tt/UapqOELq

Thanks Max for sharing the collinear’s full details. What is the dia of wire you have used?

**Later addition: **
I have noted some contradiction in coil dimensions in this drawing.

It says the coil consists of 1½ turns of 10 mm dia. The length of wire in coil therefore works out to π x d x 1.5 = 3.14 x 10 x 1.5 = 47mm. Adding 4 mm wire to provide gap between turns, the total wire length becomes 51 mm. However the drawing mentions “total wire length in coil = 65.5 mm (¼ wavelength)”.

How have you made your coil?

(a) Took 65.5 mm wire length and wrapped it into 1½ turns. This coil will have dia of 13.9 mm & total wire lenght of 65.5 mm.
OR
(b) Took some length of wire, wraped 1½ turns of 10 mm dia coil, and cut the extra length. This coil will have dia of 10 mm & total wire length of 51 mm.
OR
(c) Took 65.5 mm wire length and wrapped it into 10 mm dia coil. This coil will have nearly 2 turns instead of 1½, and total wire lenght of 65.5 mm.