RG-6? problem

Last month I moved my antennas from my roof to a push up pole on the side of my house using all nothing but RG6 cable I have.I installed proper grounding and mechanical fastened. Cables are over 60 feet in length and I have to say I think I get a little better performance than I did before when I had a tripod centered on my roof and shorter cables.I say pay close attention to the cable condition, proper installation of the connectors making sure of clean cuts of the cable and proper stripping. If possible use the proper tools. I will post some pictures of my new antenna farm.

One more picture. The proper cable stripping and crimping tools


It sure looks like it.
It’s not that your RG6 is ‘counterfeit’ - (The RG6 Spec. specifies dimensions, but not performance).
Either due to poor materials or poor assembly, what you have seems to be junk.

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So if the Spec specifies dimensions (and presumably not materials), how do you know what to buy? Are there certain sellers who you depend on, and others like Aazon to avoid?

Buy from a reputable retailer, whether through Amazon or otherwise, and look for branded coax rather than unbranded stuff from an unknown manufacturer. Cable from companies like Webro, Belden, Times Microwave etc will be of good quality.

I have a length of Webro WF100 that I’m using which is both good quality and available pretty cheaply here in the UK since it’s widely used for satellite TV installations and has lower loss than RG-6. It’s a good alternative if you don’t want to spend the money on proper 50 Ohm stuff, and if you are using an LNA at the antenna you likely won’t notice the difference.


I am using now a per-connectorized RG6 cable from Amazon, but I also have a preamp up at the antenna: Amazon.com
Works great.

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I was able to get out today and spotted this at Walmart. 15 usd. That’s cheap for cable stripper and crimper.

I thought I would report back on my recent experiments and update you: I discovered that my original problem was not the RG-6 but a bad F-type/SMA adapter. Visual inspection doesn’t identify it as bad-- I didn’t suspect that this was the problem until I found another adapter during my frequent experiments and happened to use that one. However, I didn’t realize this until after I gave up on the RG-6 and built an enclosure to hold an RPi Zero, my FlightAware Pro and a voltage regulator for use on the pole about a metre below my Franklin antenna. I used some repurposed outdoor DC cable to feed 12v to the pole box. Voltage drop over the 8 metres was 1v because the RPi Zero only draws about 200mA.
The enclosure is 3d printed in PETG.

At any rate, the result is excellent performance compared to my indoor setup: I’m tracking around 750 aircraft a day over the past three days, some well past 200 nm.


I wasn’t sure if the RPi Zero would be able to keep up, but when I “top” the device while it’s processing 200 messages/second, it’s running under 80% load.

The RPi Zero

Radio and regulator

Completed enclosure on the pole

On the mast, just in time for tropical storm Erin


You can always disable MLAT if you want, that should reduce CPU usage quite a bit.
But no need if it’s working fine :slight_smile:

Did you adjust the 5 V regulator to 5.1 V or is it not adjustable?

Glad you got it figured out, do you have a picture of the antenna?

Here’s a photo of the antenna, such as it is:


I don’t see any dropouts from MLAT demand, so I’ll keep things as-is for now.

The regulator is a fixed 5v switching regulator. I had considered shielding the supply, but decided to leave it out, as it presented some mechanical difficulties and a risk of shorting. I may go back in later and line parts of the interior with copper foil, but any emf from the regulator doesn’t seem to negatively affect the other components.

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Is that a 3D printed colinear feedpoint mount with stabilizing arms? Nice work there! You’ve got me wanting to try to make one of those antennas because that’s great range you’re getting.

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From where you purchase enclosure for your pole mounted hardware (radio & pi)? Is it a 3D printed stuff? Nice build.

Your Franklin collinear antenna is neatly built. The stubs are well formed, arms straight.

From which web site you used the design of Franklin collinear antenna? Can you please provide a link?

The plastic feed point case and support for antenna arms are very nice, seems 3D printed.

I only steal from the best: your “ADS-B DIY Antenna” posting on forum.planefinder.net from Feb 7, 2014 :grin:

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Yes, I design in Fusion360 and then print using PET-G–basically the same stuff that plastic water bottles are made of.

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Yes, it’s 3d printed, from my own design. I think that if I were to do it again, I’d beef it up a little more. Not sure how well it will handle the tropical storms that we get here in Nova Scotia every fall. Nice thing is that if it breaks, I just tweak the design and print a new one.


There is one disadvantage of Franklin Collinear antenna: During rains, water drops will fill the gap between two horizontal wires of stubs, creating a short-circuit, and will result in poor performance.

However this is a temporary situation, and when rain stops and rain drops dry up, the antenna starts performing ok. If I recall correctly, @triggers and @bramjacobse have faced this situation.

Although I have used Franklin Collinear for a considerable period, even during rains I did not face this problem. My entire installation, including antenna, is indoors :wink:

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I noticed this earlier today: a pronounced dip in reception as soon as the rain started. Reception improved a few minutes after the downpour. Thanks for the confirmation… “Misery loves company”.

Thanks for inspiring me to make my own! Boy, adjusting the feed point really makes a huge difference. When I built it, I mistakenly put the feed point in the middle of the matching stub and it was pretty awful. Then I RTFMed and saw it was supposed to be at 18mm from the bend, adjusted and I’m showing 15dB return loss or about 1.433 SWR (reference was about -7dB at 1090MHz)

I 3D printed a basic terminal block with M3 screws and nuts to do the feed point slide since I don’t have any terminals that have holes that go through. I’ve gotta come up with some sort of way of mounting it before I can take it up to the attic to try it out. Sorry about derailing the thread but DIY antennas are so cool.

This thread is for Franklin Collinear Antenna.

Has anyone tried a collinear antenna like this?