Why do i have no signal when close to duna?

[modybird]

I have 2 RA-2 antenas and idk whats wrong. 

 

https://imgur.com/a/ON9hwod

[Superfluous J]

Without using the game and only going by the wiki, 2 RA-2's aren't going to reach to Duna when Kerbin's on the other side of the Sun.

https://wiki.kerbalspaceprogram.com/wiki/CommNet

[Rauko]

Cant see the pic,but... first lets check the more tipical causes:

maybe duna is between you and kerbin? You need direct line of view.

Or you have disable "ground stations" and the ksc is just in the other side of kerbin.

[Snark]

 

On 12/30/2018 at 3:06 PM, modybird said:

I have 2 RA-2 antenas and idk whats wrong.

The problem is that your antennas just aren't powerful enough for that distance.

If you've got two RA-2 antennas, that will have a combined antenna power of 3.36G.  So, how far can that talk to Kerbin?  Depends on the level of your tracking station:

• Level 1 (2G):  max distance 2.59G meters
• Level 2 (50G):  max distance 12.9G meters
• Level 3 (250G):  max distance 29G meters

That's how far your antennas can reach.  So, the next question is, how big is the distance from Duna to Kerbin?

Well, that varies a lot-- it depends on the relative positions of the two planets.  Kerbin orbits at 13.6G meters from the Sun, Duna at about 21G meters.  So, the distance between the two planets can range anywhere from 21 - 13.6 = 7.4G meters at their closest, up to 21 + 13.6 = 34.6G meters at their farthest (when they're on opposite sides of the sun.

So what does this mean?

Well, it means that you don't have enough antenna power to cover Duna's entire orbit.  If your tracking station is level 2, then you've got enough power to communicate when the two planets are at their closest, but most of the orbit will be too far away.  If your tracking station is level 3, then you've got coverage for most of the orbit... but still not quite enough when they're at their farthest.

What it boils down to is that the RA-2 antenna is really just not powerful enough for interplanetary communications, unless you stack a whole bunch of them and/or have a very powerful transmitter back home.

Sending a probe with a better antenna (e.g. the RA-15) would be one way to solve this.  Another possible solution-- if the planets aren't at their farthest, and if you currently have a level 2 tracking station-- is that you could upgrade the tracking station to level 3, which will give you coverage of most (though not quite all) of Duna's orbit for that spacecraft.

On 12/30/2018 at 3:12 PM, Rauko said:

maybe duna is between you and kerbin? You need direct line of view.

No, that's not the problem here.  The screenshot makes it clear that the ship is very high above Duna, out near the edge of the SOI, and the planet isn't in the way.  He simply doesn't have enough antenna range.

On 12/30/2018 at 3:12 PM, Rauko said:

Or you have disable "ground stations" and the ksc is just in the other side of kerbin.

Also probably not the problem.  With just a couple of RA-2's, it's likely he couldn't have comms even if KSC were staring straight at him.

[Rauko]

Ok, thankyou snark, as I said, I am unable to see the pictures in my phone, and I dont use the stock comm network system, so I am unfamiliar with exact distance requirements in stock. Just gave a pair of common "out-of-signal" causes to the OP to check while waiting for a more complete response from you or other experts.