coax question help

[marcdeklerk]

Hi All, just got my RB last week, just a quick question:

I have the BS1100 antenna on the roof using it with RG8X coax cable 15meter. and the supplied indoor antenna, indoors give me greater range than the outdoor antenna? Is my RG8X coax cable that bad?

what about getting a JIM75 pre-amp? will this help me?

thanks
MARC

[Allocator]

Hi All, just got my RB last week, just a quick question:

I have the BS1100 antenna on the roof using it with RG8X coax cable 15meter. and the supplied indoor antenna, indoors give me greater range than the outdoor antenna? Is my RG8X coax cable that bad?

what about getting a JIM75 pre-amp? will this help me?

thanks
MARC

Marc,

I have both the SBS-1 and RadarBox.  I also have the BS1100 external antenna with the standard supplied co-ax.  Before I discuss my findings, there are some very simple rules to understand here:

- The RadarBox antenna is not an internal antenna

- The antenna must be outdoors and clear of obstructions

- The higher the antenna, the better

- The shorter the co-ax the better

So, if you sit on the roof of your house with a laptop and the standard RB antenna, you will get the best picture you can, unless to go to the top of a tall hill or mast :-)

I have used the SBS-1 with the standard and external BS1100 SBS antenna, and I have used RadarBox with both these and the RB antenna.  Whilst my test are not especially scientific, this is what I've found:

- The BS1100 antenna is mounted externally and is about 2m higher that the standard SBS magnetic antenna and the RB antenna.  Both the SBS magnetic and the RB antennas are mounted on the outside of a Velux roof window about 0.5m below the ridge of the roof.

- SBS performance using the BS1100 and the SBS magnetic antenna is almost identical - The BS1100 is higher, but the magnetic antenna has a much shorter co-ax.

- The SBS-1 performs well on the magnetic antenna and so does RB on it's standard antenna.  The performance of both boxes running side by side on their own antennas is almost identical.

- I've tried running RadarBox using the BS1100 and the SBS-1 magnetic antennas and I don't think that the performance is as good as with the standard RB antenna - which was a bit of a suprise to me as the RB antenna looks a bit "cheap".

Remember, whichever antenna you use, you need a groundplane - the metal disk the size of a CD that comes with RadarBox, or a 30cm square metal plate I use with the SBS-1 magnetic (the BS1100 comes with it's own groundplane in the form of 3 small horizontal stub antennas)

As for the pre-amp, if you look at the Kinetic forum, you will see arguments for and against.  Some people swear by them, other say that make reception worse as they increase noise but not the signal.

I am currently using RadarBox at work with the SBS-1 magnetic antenna on the window ledge at groud level.  Because the window is south facing, I can see aircraft out to 150 miles in that direction.  Coverage to the north is masked by the building, but I can still see some aircraft out to 20 to 30 miles.  By moving the antenna 10 cm in each direction, I can change the reception dramatically.  By lifting it 30 cm, the range is increased.

I suggest that you experiment with your existing antennas before purchasing a pre amp.  Try installing RadarBox on a laptop and move the laptop and antenna to different locations and see what happens.

I live in the country with few buildings around me, and if I put my magnetic antenna on top of my car parked outside my house and use the laptop, I get better range than using the BS1100 on top of the house!

All the best

Allocator

[AirNav Support]

Just to add to Allocators informative post.

Its best to keep the coax between the antenna and RadarBox as short as possible. Most people usually say anything longer than 10 metres will suffer from signal loss and hence a amplifier next to the antenna is needed to compensate the loss.

Have a chat with some of our delears who will be happy to give you more information and suggestions on what to buy to improve reception.

Hope that helps.

[davis]

My Experience....


With the original antenna on the balcon of my house in the center of the city I have a maximun range of 30 miles where the sky is free from houses and trees.

Near the sea and with the antenna over the car roof, with all the sky free i have a maximun range of 241 miles withe the aircraft at FL 390.

I have take the radarbox on the Alghero (AHO/LIEA) Airport ATC Tower and with the original Radarbox antenna i have a complete range of 300 Miles!!  I have taken hundreds aircraft from over Genova to over Algeri and Tunisi and over Rome to Over Baleari Island!!

I tell you this because the original antenna works very good if the entire area near antenna is clear!  if you use the antenna in an area with a lot of barriers you cannot see a lot of flights because the frequencies that ADB-S use is very high and the minimum barriers cancel the signal.

[marcdeklerk]

thanks guys!! will let you know what i do

[viw]

Hello marcdeklerk,

I am using an (ex military) 1090 Mhz Antenna which I bought in England via ebay, I have about 18 m of low-loss Coax Cable (Ecoflex 10 from Wimo (www.wimo.de) from the antenna to the Radar Box.

My antenna is mounted on the attic (below the roof) of my house about 6 m above ground. I cannot set up a lightning protection, therefore I´m frightened to put the antenna outside on the top of the roof.

I do have a lot of mountains in my area so my reception is limited in some directions, but in the non obstructed direction I receive flights up to 140 NM, which I think is very good for an antenna below the roof.

I think the coax cable quality (low loss) is very important for the range of reception.

Now I´m thinking about getting the AS-1090 amplifier from Wimo to improve the reception further (so I hope)

Best regards
Gerald

 

[Roadrunner]

I have an SBS1 with a BS1100 antenna in the loft and get up to 210 miles in certain directions but have a black spot in line with the chimney breast in which direction only 50 miles is covered. My Radarbox has the standard antenna and is located on the window sill in my Den with 200 miles in the directions seen from the window and down to 30 miles in the opposite directions. I hope to get the BS1100 on the roof but have yet to find anyone with better reception with other than the standard antenna for Radar Box. 

AirNav have you given any though to possibly coming up with something that could be used for roof mounting  with up to 15 metres of cable? as I am sure that if you could do with a roof antenna what you have achieved with the standard antenna I am sure it would be formidable.

Mike

[AirNav Support]

There hasn't been a dissucion regarding the antenna for awhile. We can certainly look into a external antenna.

Will get back to you as soon as we have news.