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Author Topic: Antenna in the loft - Height isn't everything!  (Read 17090 times)

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bratters

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Re: Antenna in the loft - Height isn't everything!
« Reply #15 on: February 18, 2010, 04:49:38 PM »
Further to the above, I checked the aerial effectiveness purely by MyFlight numbers and distances.

Easier if you can co-opt an observer!

Brimon

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Re: Antenna in the loft - Height isn't everything!
« Reply #16 on: February 18, 2010, 05:24:49 PM »
Brimon - yes, this really encapsulates the "loft" problem and the thread title "height isn't everything".

While the extension USB gives you the freedom to move box and aerial about, it doesn't help finding that elusive "sweet spot" is. Not necessarily high, not necessarily central, not necessarily anywhere in particular.

There's really no advice I can give you, it defies logic and is purely down to trial and error.

Best I can say is Good Hunting.

Thanks for that Bratters, will trial & error basically. I am just concerned that rather than positioning I losing distance because of the length of cable now involved between the Radarbox & PC.
Chasing the heavies from a secret bunker in Scotland

bratters

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Re: Antenna in the loft - Height isn't everything!
« Reply #17 on: February 18, 2010, 05:58:57 PM »

Thanks for that Bratters, will trial & error basically. I am just concerned that rather than positioning I losing distance because of the length of cable now involved between the Radarbox & PC.

No, not if I understood you correctly. The length of your USB cable is immaterial in terms of degrading signals; it's aerial cable that is responsible for signal loss.

I'm currently using around 12 metres of USB, but the aerial cable is the supplied one. Signals were never better.

Do let us all know how you get on and whether you can come up any "scientific" theory for siting your aerial in the optimum position - if and when you find it.

(I find a stack of cardboard boxes and biscuit tins come in handy)

Allocator

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Re: Antenna in the loft - Height isn't everything!
« Reply #18 on: February 18, 2010, 06:06:37 PM »
The length of the USB cable is more likely to introduce power problems resulting in RB disconnecting due to lack of power.  I'm not sure why the maximum length of a 'normal' USB cable is set at 5M though - could that be a power issue?

bratters

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Re: Antenna in the loft - Height isn't everything!
« Reply #19 on: February 18, 2010, 06:23:32 PM »
Brimon seems to be using 5mtr active Allocator.

Both my 5 mtr active cables came with a further 5 mtr of "normal" cable thus giving a 10 mtr functional run which the manufacturers virtually guarantee to be effective. I haven't tried stretching to 15 mtr but I would anticipate that would be a bridge too far and my 40 feet is pushing the limit.  Still,  it's a helluva of a lot better than 40 feet of aerial.

I suppose the conclusion is that for non-active USB cable 5 mtr is the effective limit.

Brimon

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Re: Antenna in the loft - Height isn't everything!
« Reply #20 on: February 18, 2010, 06:35:01 PM »
Brimon seems to be using 5mtr active Allocator.

Both my 5 mtr active cables came with a further 5 mtr of "normal" cable thus giving a 10 mtr functional run which the manufacturers virtually guarantee to be effective. I haven't tried stretching to 15 mtr but I would anticipate that would be a bridge too far and my 40 feet is pushing the limit.  Still,  it's a helluva of a lot better than 40 feet of aerial.

I suppose the conclusion is that for non-active USB cable 5 mtr is the effective limit.

Bratters I am indeed using 5m active. Thanks for comments regarding cable not affecting signal. I don't know about a "scientific" solution.
I did think about putting the wife in the loft holding the aerial in various positions
for the weekend, don't think she'll be too keen though.

Appreciate the reply's by everyone, thats what makes this a very good forum,Cheers.
Chasing the heavies from a secret bunker in Scotland

Allocator

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Re: Antenna in the loft - Height isn't everything!
« Reply #21 on: February 18, 2010, 06:38:32 PM »
I use the Cat 5 USB extender that gives me up to 50m extension - and it provides the power faultlessly as well :-)

EMA

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Re: Antenna in the loft - Height isn't everything!
« Reply #22 on: February 18, 2010, 06:46:09 PM »
I think one of the reasons my loft aerial performs nearly as well as when I had it on the roof is the shorter antenna cable length used in the loft meaning less signal loss.

Allocator

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Re: Antenna in the loft - Height isn't everything!
« Reply #23 on: February 18, 2010, 06:49:37 PM »
I ag
I think one of the reasons my loft aerial performs nearly as well as when I had it on the roof is the shorter antenna cable length used in the loft meaning less signal loss.

You are right, antenna as high as possible and antenna co-ax as short as possible - it just has to be the best solution.