AirNav Systems Forum

AirNav RadarBox and RadarBox24.com => AirNav RadarBox and RadarBox24.com Discussion => Topic started by: Johnn on October 27, 2009, 07:14:38 PM

Title: Will 15 m Or Maybe 20m of Westflex 103 take my signal down alot?
Post by: Johnn on October 27, 2009, 07:14:38 PM
Hi There,
I ask this Q because  I would like to get my radarbox antenna up a tad higher, At the mo I am just about getting 70 nm right around my location. I have 10 m of W103 coax at the mo, but will I be doing more harm than good if I put the antenna up higher with more co-ax?
Many Thanks
John
Title: Re: Will 15 m Or Maybe 20m of Westflex 103 take my signal down alot?
Post by: RodBearden on October 27, 2009, 08:39:27 PM
I can tell you that I've got 15m of W103, no pre-amp, and I'm very happy with the setup - range in the right direction around 200nm.

Rod
Title: Re: Will 15 m Or Maybe 20m of Westflex 103 take my signal down alot?
Post by: Johnn on October 27, 2009, 08:44:55 PM
Wow! Thats great!, Many thanks for your post, I will stick with the 15m I was thinking about.
Thanks John
Title: Re: Will 15 m Or Maybe 20m of Westflex 103 take my signal down alot?
Post by: anorak on October 27, 2009, 09:56:14 PM
Hi John, I over estimated to be on the safe side and got Henry to make me a 20 mt lead with the surplus coiled in the loft. (Thank heavens Her Highness doesn`t get up there.)  I`ve put a screen shot, hope it`s of some help.
Dave.
Title: Re: Will 15 m Or Maybe 20m of Westflex 103 take my signal down alot?
Post by: Fenris on October 27, 2009, 10:11:42 PM
Probably worth saying that it would take almost 30m of Westflex 103 to have the same loss as the RG-174 that is supplied with the antenna you get in the RadarBox , er, "box"!

Westflex 103 is about 1.3dB per 10m, whereas the RG-174 is about 3.5dB for the 3m that is supplied.
Title: Re: Will 15 m Or Maybe 20m of Westflex 103 take my signal down alot?
Post by: Jeremy on October 28, 2009, 12:11:02 AM
I would suggest you do not get into too much concern over cable loss. At these frequencies you are dealing in receiving direct line of sight. If you are surrounded by hills then it will not make any difference to cable losses as the signal will not be there. What RF you can see, is what you will get. Any building, tree or hill will be an RF block.
Good luck.
J.
Title: Re: Will 15 m Or Maybe 20m of Westflex 103 take my signal down alot?
Post by: Fenris on October 28, 2009, 09:35:37 AM
However, in directions that are not blocked, that loss will restrict range so you can't ignore it completely.
Title: Re: Will 15 m Or Maybe 20m of Westflex 103 take my signal down alot?
Post by: g0seg on October 28, 2009, 11:44:35 AM
Hi there, location is Pontefract west yorks. I am 150 asl and have a 30 foot mast for radio ham work - i`ve mounted the little curlywhirly supplied at 30 feet with 66 feet of good quality satellite cable - Ok, it`s at 75 Ohms but it`s for receive only. As others have rightly mentioned, height is the thing and i think a few more yards of decent coax won`t do much harm. Been running the new 3.07 version for a week and have kept the polar diagram for that time - see attachement. Regards and good luck, Roger PS No preamp used - too close to transmitting antennas.

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Title: Re: Will 15 m Or Maybe 20m of Westflex 103 take my signal down alot?
Post by: anorak on October 28, 2009, 07:01:06 PM
Does that tech speak mean I`ve got something right for a change?
Dave.