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Author Topic: What a difference the cable makes!  (Read 4349 times)

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steve1970

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What a difference the cable makes!
« on: February 17, 2010, 04:05:47 AM »
Hello everyone! Only new here so please be gentle :-p

I'm in Melbourne, Australia about 5nm south of YMML.
Bought the radarbox on the 15th of Feb, a few days ago.
First day just had the antenna sitting on a shelf above my desk worked ok,
then, same day it went up on the roof as far as possible with the standard antenna cable length. Much better!
Yesterday hooked up the extension cable of RG58 and it went up about 5 meters on a bracket underneath one of my discones. Not good at all!! The null spots I had with it sitting on the roof had become better, but the overall range actually decreased was only getting about at max 65nm where with it just sitting on the roof would have peaks up around 100nm but really bad null spots.
Today I replaced the rg58 with rg6.... omg what a difference that made.
Have gone from about  20 flights max to about 70 at about the same time and the range has blown out to about 150nm... Happier :-)
Still have some null spots NW and SE of me where it maxes out at about 70-80nm but overall much happier. It's only been running about an hour but what an improvement!
Tomorrow I'll move the antenna to a different location to see how that goes. Might not like being near the discone.
Sorry for rambling but I got all excited lol.

Edit just a quick update can see some aircraft taxiing not before! So 100% better, starting to like this bit of kit more and more :-)

Ready to take the next step I think! Ok being here in Australia can anyone recommend somewhere where I can buy good quality cable (low loss) and a dedicated outdoor antenna that would be better than the standard ant supplied?
Look forward to the replies :-).
Thanks guys
Steve



« Last Edit: February 17, 2010, 06:23:17 AM by steve1970 »

gleff

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Re: What a difference the cable makes!
« Reply #1 on: February 17, 2010, 07:50:57 AM »
Hi Steve,

I'm in Sydney in a the middle of a chatswood surrounded by glass buildings facing the opposite direction to a flight path, and about 12 nautical miles from Kingsford Smith airport (approx).  I also live in an apartment building about 1/3rd of the way up the building.  I've got very very little visible sky.  With the stock antenna and cable, I was getting a maximum of about 15-20 nautical miles on a good day and huge (massive blind spots).  The signal was el crappo at the best of times.

All of my aircraft signals come from glass reflections in the surrounding buildings LOL.

Anyway, I couldn't find anything decent in Australia so I bought the following and also bought 5 metres of westflex 103 cable and had them shipped to Australia.  Wasn't that expensive either.  The service from both of the sites was great.  Had to order via paypal and email but received both items from two different places in the UK in about a week.

The antenna was from here: http://www.ssejim.co.uk/26-sseads1090sj.htm  The guy that sells them and makes the brackets is named Jim and was very helpful.

Anyway, the difference between the stock and the external with the westflex cable is like night and day.  I still get all my signal from reflections, and still lose signal pretty often, but it's very much improved.  I now regularly pick up aircraft about 215 nautical miles away.  Unfortunately, I still have my blind spots so the 215 nautical miles is only in one direction, but I still get much improved signal from other directions as well.

The antenna now sits on my veranda railing at my apartment.  Still surrounded by buildings with very little visible sky.  I would highly recommend this antenna with the Westflex cable if you're wanting to improve your reception.  It's not ideal to order from the UK instead of Australia but then again, the quality of the imported antenna and cable is well worth it in my opinion.

Geoff
« Last Edit: February 17, 2010, 07:52:54 AM by gleff »
http://www.flighttracker.gleff.com - based in Sydney, Australia

steve1970

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Re: What a difference the cable makes!
« Reply #2 on: February 17, 2010, 11:57:05 AM »
Hi Geoff,
Thank you for the reply. It's hard to find stuff like dedicated antennas and stuff here in Aus oh well can't help that!
Well I'm getting more and more into this, always been into air band monitoring with scanners and plane spotting etc and I suppose this is part of my evolution lol, always wanted one of these radarboxes for a long time but always thought of the expense but the other day it was one of those "what the hell days" lol!
Now I'm already wanting to make it better hehehe.
As I'm writing this I'm back and forward to the site you suggested.... If it made such a difference for you I'm getting sort of excited thinking what I can do!! I can do masts etc with no probs no real height restrictions either, good neighbors lol. Already looking at that page thinking about what to order hahahaha.
Thanks again for the feedback appreciate it :-)

Steve
p.s well just with the stock antenna and the rg6 got a nice looking Maple leaf pattern out to about 120nm average peaking at 170nm southbound. About 80 - 100mn on the nullish spots.

gleff

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Re: What a difference the cable makes!
« Reply #3 on: February 26, 2010, 08:49:21 AM »
Hi again Steve,

I thought you might want to see my polar diagram to show my range using the above antenna.  Things to bare in mind though.

1. I have no visibility of aircraft as i'm surrounded by glass buildings, so the majority of my signal is likely reflections from the buildings.

2. This polar diagram is just from the Radarbox 3D v4.03 so it's not overly complete.

3.  You'll notice the spike out west.  I picked two aircraft up this evening at that furthest point being 217.2nm.  

4. My old polar diagram had the furthest point actually in the direction past Canberra and almost at the NSW, Victorian border also at 217nm.

In your situation, if you were picking up 120nm peaking at 170nm as a maple leaf pattern using the stock antenna, I shudder to think what you would get with this or any other external antenna.

Let me know how you go with any new antenna you get.  I'd be very interested.

Cheers
Geoff
« Last Edit: February 26, 2010, 08:51:17 AM by gleff »
http://www.flighttracker.gleff.com - based in Sydney, Australia

pjm

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Re: What a difference the cable makes!
« Reply #4 on: February 26, 2010, 10:00:26 AM »
I'm in Sydney in a the middle of a chatswood

For reference I'm also in Sydney, and use one of the Airnav radar extender antennas. fwiw the preamp actually reduces my range so I don't use it. Seems to be overloading the Radarbox here for whatever reason..

# RADAR-EXTENDER Antenna
# 1m low loss cable Westflex-103
# Mast pre-amplifier AS-1090
# 10m low loss cable Westflex-103
# AS-1090BT Bias-T for DC-Feed
# 1m Cable BNC/SMA

here is my current polar diagram (and a photo of the antenna).



« Last Edit: February 26, 2010, 10:02:13 AM by pjm »