Maximum range

estcan5 · May 24, 2010, 04:57:31 PM

Hello!

I´d like to ask that could it be possible to receive the Mode-S/ADS-B max. range of 200nm with the DPD Productions antenna and in this case, do I need a preamplifier? Or does anybody know some other antenna that can surely get 200nm?

Best regards,
William

CoastGuardJon · May 24, 2010, 09:08:11 PM

Hi William, there's been a lot of discussion on pre-amps - they will only amplify the signal if there's one there in the first place - their best use is to boost a signal over a longer length of co-ax. I get up to 275nm (on irregular occasions), but regularly 230nm. This is with the basic standard antenna that comes with the RB. What I have going for me is my location, on top of 185' asl cliffs, AN twig at some 30' above that, so roughly 215' with a clear horizon to the west. If you're in a valley, or surrounded by high buildings, reception could be limited to 35 - 65nm, as I get to the east, restricted by the roof ridge which runs n - s and about 5' above the twig.

estcan5 · May 25, 2010, 01:00:56 PM

Thanks for your answer, CoastGuardJon. The terrain around my home is quite ´´boring´´, but I´m still on top of a smaller hill and there seem to be no such high buildings which could stop the signals. Does anybody have some experiences about the DPD antenna, that is it possible to get at least 200nm with our without a pre-amp and as I expect, the cable is probably going to be pretty long, so witch pre-amp could be the best according to your experiences?

William

malc41 · May 26, 2010, 09:29:36 AM

William
I have the DPD aerial mounted about 20' high with a clear view to the east (from about 000 to 180 degrees) no pre-amp and on a good day will pick up about 180 miles. As CoastGuardJon stated the pre-amp will only pick up a signal if its there to start with.
The signal can be dependent on the altitude of the aircraft and line of sight.
In my experience the pre-amp are not the best way, as the more connectors you have in line, the more chance of water ingress etc

Malc

imropes · June 24, 2010, 06:59:05 PM

On the subject of max range, the troposphic charts look very good for Monday. Good lift on way. Should be interesting on RB and 2 meters.

bratters · June 24, 2010, 08:38:34 PM

Quote from: estcan5 on May 24, 2010, 04:57:31 PM
Hello!

Or does anybody know some other antenna that can surely get 200nm?

200+ miles in some directions (see pic) using this:

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

estcan5 · June 24, 2010, 08:59:56 PM

Seems good.

Chris11 · June 25, 2010, 04:16:14 AM

Quote from: imropes on June 24, 2010, 06:59:05 PM
On the subject of max range, the troposphic charts look very good for Monday. Good lift on way. Should be interesting on RB and 2 meters.

Could you expand on this. Where do you get the charts and what effect does the troposphere have in the signal?

imropes · June 25, 2010, 06:34:08 AM

www.dxinfocenter.com/tropo Signals can on some occasions travel further than normal line of sight by high pressure weather systems. These charts show you the areas affected.

Chris11 · June 25, 2010, 06:43:49 AM

Thanks

Chris11 · June 25, 2010, 08:04:15 AM

South Africa :)

Our weather services does supply information an the height of the troposhpher and was interested to see what effect it has on a signal that I thought was direct line of sight