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romdouk

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:)
« on: September 10, 2010, 08:40:46 PM »
?
« Last Edit: February 17, 2011, 10:01:07 PM by romdouk »

Runway 31

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Re: External Aerial
« Reply #1 on: September 11, 2010, 07:46:31 PM »
Terry,

I got mine from here.  Very good quality and Dave was very helpful.

http://www.dpdproductions.com/

Alan

orkney

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Re: External Aerial
« Reply #2 on: September 11, 2010, 08:33:44 PM »
hello

We have been using one of these ( http://www.rocketradio.co.uk/radar-extender-external-antenna-for-radarbox--sbs-1-1500-p.asp ) antennas for over a year with 15m westflex 103 and have consistently received aircraft over 200NM in our favourable directions (sometime up to 270 in good conditions). Also if you are in a windy position ours has stood gales gusting 60-70mph without even shaking too badly. Also we don't use any amplifiers although our coax is quite long.

Andrew

Alan Parker

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Re: External Aerial
« Reply #3 on: September 12, 2010, 08:46:56 AM »
Terry. I had the same problem with my Radar Rama,it worked fine to begin with then as you say it struggled to reach 80 miles so i replaced it in the end for the same antenna as Orkney. Only had it for about a month but the results have been great. Constantly getting 200 plus miles & averageing over 100 in my flights where as before it was around 60-70. So far i've been really impressed with the antenna & would recommend it.

bratters

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Re: External Aerial
« Reply #4 on: September 12, 2010, 09:24:13 AM »
This is my aerial and I've got 150-200+ nm right round the compass.

http://www.anchorsupplies.com/radarmax.htm

ENKB

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Re: External Aerial
« Reply #5 on: September 12, 2010, 09:25:06 AM »
I recieved my "radar extender" antenna last week and put it op on the roof yesterday... BIG Disapointment :( .
In the process of fault seeking  i measured the antenna with an ohm meter an found no contact between the poles, is this correct ? Shuld it not read 50 ohms ?

viking9

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Re: External Aerial
« Reply #6 on: September 12, 2010, 09:55:52 AM »
No, 50 ohms is the impedance - not the DC resitance. Impedance is more complex than resistance because the effects of capacitance and inductance vary with the frequency of the current passing through the circuit and this means impedance varies with frequency! The effect of resistance is constant regardless of frequency.

Is your antenna well clear of parallel walls, trees and other obstructions and has it a good line of sight in all directions?

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

ENKB

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Re: External Aerial
« Reply #7 on: September 12, 2010, 10:06:50 AM »
I have an homebuildt antenna placed on the same roof, and this is picking up signals as far as 180 nm away. Svitching to the radar extender signals dissapears. Seems i must check the wiring again ..

rashers

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Re: External Aerial
« Reply #8 on: September 12, 2010, 01:43:22 PM »
hi lads i have a radar extender ordered is it true i also have a dimond 777 ordered puting the 2 up on a 10 foot pole sould i csee good results from these antennas is it true if the 2 antennas ar side by side will it affect the radar box reception

Alan Parker

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Re: External Aerial
« Reply #9 on: September 12, 2010, 04:41:03 PM »
rashers. i have the same two antennas mounted on the same mast side by side at the same height & haven't noticed any loss from either.

Alan Parker

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Re: External Aerial
« Reply #10 on: September 13, 2010, 01:25:33 PM »
RocketRadio seem to be about the cheapest i could find . If you use the link that Orkney posted higher up the page, you should be ok.

orkney

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Re: External Aerial
« Reply #11 on: September 13, 2010, 01:55:01 PM »
Hello

I find that Rocket Radio has always given great service too as we have bought several items from them and normally reasonably priced but its always a good idea to check.

Andrew

ENKB

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Re: External Aerial
« Reply #12 on: September 19, 2010, 11:35:36 AM »
No, 50 ohms is the impedance - not the DC resitance. Impedance is more complex than resistance because the effects of capacitance and inductance vary with the frequency of the current passing through the circuit and this means impedance varies with frequency! The effect of resistance is constant regardless of frequency.


But is no connection at all between the two poles of the antenna normal ?

viking9

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Re: External Aerial
« Reply #13 on: September 19, 2010, 12:35:11 PM »
An ohmmeter across the coax centre and braid will indeed show infinite or very high resistance.

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

RobinB

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Re: External Aerial
« Reply #14 on: September 19, 2010, 01:32:49 PM »
yes, that is how it should be.