Antenna coverage comparison

Started by NF2G, March 17, 2010, 08:50:22 PM

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NF2G

The RadarBox documentation advises against long coax feeds to rooftop antennas due to likely signal loss in the cable (unless you use hardline).  I compiled a polar plot map with the supplied magnet mount antenna sitting on top of a curtain rod in my 1-storey house.  Then I connected the RadarBox to my multicoupler, which is fed by a discone at 30 feet above ground level using about 70 feet of Belden 9913 cable.  (The antenna is at the far end of the house.)

The upper screen shot shows the polar plot for the original antenna.  The lower shot is the plot for the discone on the tower.  While there was some improvement in coverage in a couple of directions, the overall effect is not large.  This is probably because of coaxial cable losses.


NF2G

#1
The rooftop antenna didn't make much difference due to cable losses, but changing windows was another story.

The previous polar map was made with the supplied antenna on the curtain rod over my south-facing window.  The one below is with the antenna over my east-facing window - much worse!


CZUL

Hi

I currently have my RB antenna ( supplied SBS-1 antenna) about 60ft up. Cable run is quite long almost 90ft. Reception is fantastic. I see you are near Albany. I'm the Montreal feeder. I see your coverage over network. Looks really good from here.

CZUL

naird

Great job CYUL  nice coverage paul. NF2G I'll send a screen shot from Kingston, I enjoy your coverage.



Neil


naird

here's the screen shot

[attachment deleted by admin]

viking9

Quote from: NF2G on March 17, 2010, 08:50:22 PM
Then I connected the RadarBox to my multicoupler, which is fed by a discone at 30 feet above ground level using about 70 feet of Belden 9913 cable.  (The antenna is at the far end of the house.)

I aasume your discone has a wide frequency range. An antenna cut for 1090MHz is necessary for max range.

Tom




Tom
Bury St Edmunds, Suffolk UK
15 miles SE of EGUN
32 miles SE of MAM > DIKAS track
http://www.viking9.co.uk

pure3000

just wondered, has anyone constructed a dipole for 1090mhz to see the results?