How do I map Antenna Class Types shown in KSPedia to actual antennas?

[Paul G]

I'm trying to send probes to Eve, and am having trouble being able to communicate with my landing probe once I separate from the stage that got me to Eve orbit.

The stage that remains in Eve orbit has 2 RA-2 Relay Antennas, and my Kerbin DSN Ground station has bee upgraded to L3.

I obviously want to have control over my probes during re-entry, so a big dish is out of the question, but when using a Communotron 16, or even the probe core (a Probodobodyne OKTO), as soon as I separate from the stage that has my relay antennas, I loose all control over the probe. I was expecting that the probe core, either via its internal antenna, or the Communotron 16, would relay via my stage and its RA-2's back to Kerbin, but no. The only antenna that give me any kind of connection is a DTS-M1, and that shows as communicating directly back to Kerbin, rather than through the relay. A DTS-M1 is not going to survive Eve re-entry.

I don't think its a range issue, as I loose control of my landing probe as soon as I separate, I have extended antennas, and even tried re-orienting the stage with relays just in case the stage body was occluding the signal from my probe to the relay antenna, but no luck.

The KSpedia show a table that gives ranges for different combinations of antennas - Class 0 (Probes) unto class 5, as well as the different upgrade levels of the Kerbin Ground Station, but I can't see in the parts guide what class a particular antenna would be.

I am using KSP 1.21.1604 on Mac.

Any thoughts/suggestions?

Thanks

Paul 

[Streetwind]

Rightclick the antenna in the editor. It will show you an "antenna power" rating on the right side, as well as precalculated ranges against each of the three DSN levels.

I assume the wiki page you're referring to is this one: http://wiki.kerbalspaceprogram.com/wiki/CommNet

In which case the "Antenna Type", of 5k, 500k, 5M and so on, corresponds directly to the antenna power stat you can see in the editor.

 

Now, with two RA-2's against a level 3 tracking station, you should technically be set to always have a link back to Kerbin. Check your mothership: does it have this link? If not, then you are either out of range (which might happen if Kerbin and Eve are in direct opposition, but with two stacked antennas I'd doubt it) or occluded by a moon or planet in the way. Ships never occlude signals. Or, you play with only the main KSC ground station, and it's on the wrong side of Kerbin.

If your mothership does have a link, then yeah, I'm as confused as you are. The built-in antenna of any probe you decouple should link up with the mothership and use it as a relay. Screenshots, perhaps?

 

Edited May 2, 2017 by Streetwind

[FancyMouse]

19 minutes ago, Streetwind said:

I assume the wiki page you're referring to is this one

Nope KSPedia is in-game feature. It includes a big table describing the range between all kinds of antenna versus {all kinds of antenna and all kinds of tracking station}. I highly suggest you try it out, not only because TriggerAu is awesome, but I also find I don't need to switch to an external webpage once I put community stuff like PlanetWiki into KSPedia.

 

33 minutes ago, Paul G said:

but I can't see in the parts guide what class a particular antenna would be.

The stock rating is the rating against the same antenna itself. So you basically look at the main diagnoal of the table, and find which class the antenna is. From there you know what to do next.

Of course, this only applies to stock antenna - modded antenna set their own range arbitrarily, and they don't fall into a particular class in the table. In that case you'll need to go back to the formula.

[Streetwind]

Unfortunately I have no access to KSP at this time... external websites are all I have at my disposal But yes, I have browsed the KSPedia before. On other topics, not antennas.

Edited May 2, 2017 by Streetwind

[ElWanderer]

How many antennae do you have on the mothership? As I understand it (incorrectly, it seems. Ignore what follows): To act as a relay, the mothership needs two antennae: any antenna (or antennae) that can connect back to Kerbin, and a specifically-described-as-a-relay antenna (or antennae) that can connect to your probe. It sounds like the mothership is using (both?) the "relay" antennae to talk to Kerbin, so it's unable to relay anything from the probe.

Edited May 3, 2017 by ElWanderer
I am wrong, it seems.

[Blaarkies]

37 minutes ago, ElWanderer said:

How many antennae do you have on the mothership? As I understand it: To act as a relay, the mothership needs two antennae: any antenna (or antennae) that can connect back to Kerbin, and a specifically-described-as-a-relay antenna (or antennae) that can connect to your probe. It sounds like the mothership is using (both?) the "relay" antennae to talk to Kerbin, so it's unable to relay anything from the probe.

No, that is not true.

In stock vanilla KSP, a "Relay" dish can:
- Communicate directly to KSC
- Communicate indirectly through another relay to KSC
- Be a relay for other crafts(dish or antennae) trying to communicate

Simply put, a Relay dish is everything that a direct antennae is, plus it also has the connection relaying / bouncing ability. If a direct antennae can do something, then a dish of the same strength can do the same thing and more. For comms, there is no "blocked because dish is in use" effect...a single dish can handle a thousand craft.

Now, the 2.5m probe core has the mobile command ability (put a pilot on it, make sure it has a relay dish) then it can control in-range probes without any connection to KSC. A single dish will suffice there as well.

So what is the difference? If you already have a dish on it, don't bother adding antennae. But Dishes have much more mass, the majority of them cannot be closed, are fragile, hard to fit into/onto craft because of shape/size...(i think the price differs substantially as well)

[bewing]

To act as a relay, not only do you need an antenna, but you also need a probe core. It sounds like your mothership/relay does not have a probe core on it.

 

[ElWanderer]

2 hours ago, Blaarkies said:

No, that is not true.

In stock vanilla KSP, a "Relay" dish can:
- Communicate directly to KSC
- Communicate indirectly through another relay to KSC
- Be a relay for other crafts(dish or antennae) trying to communicate

Simply put, a Relay dish is everything that a direct antennae is, plus it also has the connection relaying / bouncing ability. If a direct antennae can do something, then a dish of the same strength can do the same thing and more. For comms, there is no "blocked because dish is in use" effect...a single dish can handle a thousand craft.
 

Ah, okay. I could've sworn it worked like that (and this had caused a bunch of Question threads), but I'm happy to be wrong!

Edited May 2, 2017 by ElWanderer
Reduce size of quotation

[Blaarkies]

3 minutes ago, ElWanderer said:

Ah, okay. I could've sworn it worked like that (and this had caused a bunch of Question threads), but I'm happy to be wrong!

No problem 

What you said reminds me a lot about the Remote Tech mod having "target" dishes. With those you can have a sat with one dish pointed at KSC, and another at the other probe. Then if you change target on one dish(the one pointing at KSC) to somewhere else, you lose all connection and the satellite becomes bricked 

[Paul G]

It looks like there was something strange about the way I built my ship.

I built it with the intend of it being an orbiter (with core, relays, science etc), and as an afterthought added a landing probe (another core, heat shield, more science, and comms etc) on top of my original rocket.

Despite having all the bits needed, when I separated my landing probe, the probe lost all comms as soon as I staged, despite the stage I had just left behind being in comms with Kerbin due to the relay dishes I had kitted the stage out with.

A rebuild of my rocket *starting* with the landing probe, then working down through the orbiting stage (with relay dishes), core, and power, though to the boosters solved my problem, and I have now landed my probe and happily communicating through a relay.

Of course now I have discovered that I don't have enough power to actually send any science..... Sigh.

Back to the probe drawing board.

Thanks for your suggestions everyone.  

[Blaarkies]

12 hours ago, Paul G said:

It looks like there was something strange about the way I built my ship.

I built it with the intend of it being an orbiter (with core, relays, science etc), and as an afterthought added a landing probe (another core, heat shield, more science, and comms etc) on top of my original rocket.

Despite having all the bits needed, when I separated my landing probe, the probe lost all comms as soon as I staged, despite the stage I had just left behind being in comms with Kerbin due to the relay dishes I had kitted the stage out with.

A rebuild of my rocket *starting* with the landing probe, then working down through the orbiting stage (with relay dishes), core, and power, though to the boosters solved my problem, and I have now landed my probe and happily communicating through a relay.

You should really replicate that on a vanilla install of KSP and post it as a bug.

It seems like there is something sinister and glitchy going on there, and you mostly pinned it down 

[egoego]

21 hours ago, Paul G said:

Of course now I have discovered that I don't have enough power to actually send any science..... Sigh.

As long as you can generate power (solar panel) you can always send science. All you have to do is to uncheck "Require complete" (or something like that) in the antenna settings. The antenna will then pause transmitting until enough power is available again and then automatically continue sending. Be carefull not to do that with probes that you need to control during that time as this will empty your batteries and turn off your probe until the science is sent.

[Paul G]

On 03/05/2017 at 4:58 AM, Blaarkies said:

You should really replicate that on a vanilla install of KSP and post it as a bug.

It seems like there is something sinister and glitchy going on there, and you mostly pinned it down 

I have done a fresh install of Kerbal 1.2.2.1622 Mac OSX with no mods, and been able to replicate this - hurrah. At least I know that I wasn't imagining it.

The root cause definitely seems to be when you do not start building from the very top down (i.e. start with a core, build your comms relay and then then add a coupling on top of the stage, building the probe from the bottom down (e.g. start with an Ant engine, then a tank, then the core and comms equipment).

Once you are out of comms range to Kerbal for a Communotron 16 or HG-5, as soon as you stage the final probe, it cannot see the relay dishes plastered all over the stage that is floating a dozen feet away from it.

I've saved my game, and logged a bug.

Thanks for the advice

Paul