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Piedmonitor avatar image
Piedmonitor asked N6722C edited

NDB range limit? Any way to increase?

I am working on a project that relies on the long overwater distance of NDBs, which can be up to 600nm. Despite having a greater value set in my xml file in \PackageSources\scene the range seems to be limited to about maybe 80-100 nm? The range limit isn't called out in the SDK. I really need that range to be higher if there's any way for me to get it to actually work. Thanks!

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N6722C avatar image
N6722C answered Piedmonitor commented

The 80-100nm range seems to be reasonable

Typical service ranges of non-directional beacons (NDBs)

Non-directional beacons in North America are classified by power output: "low" power rating is less than 50 watts; "medium" from 50 W to 2,000 W; and "high" at more than 2,000 W.[5]

Class of NDB, by power rating Transmission power output, watts (W) Effective range, nautical miles (nmi)
Locator beacon 0–25 15
Low 0–50 25
Medium 50–2,000 50
High 2,000+ 75

ref: https://en.wikipedia.org/wiki/VHF_omnidirectional_range

However, like all radio communications in MSFS, Noise does not appear to be simulated, so either you have a signal or not, and if the signal is weak, there is no audible noise on it.

I am assuming the above numbers are the minimum distance for "reliable" communications.
In the real world, these Station can he heard from much further away, but their signal strength and s/n ratio may make them unreliable at those extended differences.

The addition of NOISE onto COM radio systems would be a nice addition, and technically, a rough approximation should be quite possible.
A more precise simulation , taking into account other factors, however, could get really complex.

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Alec246 avatar image
Alec246 answered boufogre commented

Just as information, I have searched online for AM Station Power Output:

"Radio transmissions are measured in Watts. The highest AM frequency wattage licensed to stations is 50,000 watts. The following list contains these stations by location and frequency. "


They can be a LOT higher than Standard Aviation NDBs. In fact, in the old days, I know it used to be common for Aviators to tune some Station and listen to the Score of a Soccer Match that was happening during the flight, and these stations could be hundred of miles away from the Plane.


I don't know if the Author intention for higher power NDBs are something in this area, but I just though this information might be relevant to the subject.

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In the old days no, even today! And usually, 121.5 becomes very active during a game.
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N6722C avatar image
N6722C answered N6722C edited

On a semi related subject .. If the Mod could do its own calculation of range, then you could achieve what you are looking for.

(1) Understand how MSFS is current,y calculating the range
(2) Do your own different calculation
(3) use that to somehow replace MSFS's calculation.

https://devsupport.flightsimulator.com/questions/1070/formula-for-nav-on-nav-and-nav-signal.html

Some similar interesting work along these lines being looked into for XP.

: https://github.com/skiselkov/libradio
Radio systems and navaid simulation library for X-Plane - skiselkov/libradio
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