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AirNav RadarBox and RadarBox24.com => AirNav RadarBox and RadarBox24.com Discussion => Topic started by: sasa1000 on April 24, 2010, 10:15:45 PM

Title: Radar Rama antenna in attic
Post by: sasa1000 on April 24, 2010, 10:15:45 PM

Is anyone using a Radar Rama 1090 MHz antenna in their attic? I am just waiting for cable etc to come for mine and I am going to mount it. Will there be a significant difference with this antenna in the attic compared to the supplied antenna in the same position. I have supplied antenna in attic just now and am trying to build a Polar diagram, but not that many flights since putting it up.

Sandy

Title: Re: Radar Rama antenna in attic
Post by: bratters on April 25, 2010, 06:56:17 AM

Hi Sandy - you may have seen from a post a couple of days ago that I have just bought a new aerial. While not a radar rama, it is similar.

Prior to putting it on the roof, I tested it in the loft for a day alongside the existing supplied aerial that I've had stuck up there for a long time. Frankly, there was little  difference. (Planes were at a premium at the time because of the volcano, but  enough traffic round here to run a reasonable test)

Conclusion: as an indoor aerial, the supplied one takes some beating - as others on here will testify - and an outside aerial "inside" won't make much difference.
Your radar rama needs  siting on the roof to get the results you want.

Title: Re: Radar Rama antenna in attic
Post by: tarbat on April 25, 2010, 07:19:21 AM

It's probably worth reading the previous threads on loft antennas:

http://www.airnavsystems.com/forum/index.php?topic=2528.msg21836#msg21836
http://www.airnavsystems.com/forum/index.php?topic=1650.msg12949#msg12949

Title: Re: Radar Rama antenna in attic
Post by: smcm on April 25, 2010, 08:02:26 AM

Outside and in the clear is best, however I used my "external" antenna in the loft for several months and got good results - apart from a big null towards Shetland due to a structure in the roofspace which had foil-backed insulation around it !

I did some reading into attenuation of radio signals by building materials and roof tiles produced the least attenuation (a bit more when wet) whereas foil-backed insulation and plasterboard gave a lot of attenuation and K-glass double glazing was very high - more than 20dB, I think.

When we renovated our house we used all these materials and mobile phone signal went from weak to non- existant, especially close to a window !

Title: Re: Radar Rama antenna in attic
Post by: sasa1000 on April 25, 2010, 01:21:16 PM

Thanks once again for good advice, It's just that I was hoping to avoid filling the house full of holes to mount brackets, though there should be holes that I siliconed up from previous brackets that I had up for weather station (have to get brackets with same mounting points though!)
Other reason is I would have to earth an outside aerial too, which is a bit more work, incidentally would earth wire attached to clamp holding the mast do for this?

Sandy

Title: Re: Radar Rama antenna in attic
Post by: donburrows on April 26, 2010, 04:41:13 PM

i have my radarama in the attic and i get good results, i am in south yorks s667qb and recieve ffrom the south coast  newcastle north and cheshire west i am not recieving anything at the moment as my radarbox is away being repaired again for the third time . its been  away thre weeks now