Direct vs. Relay Antennas

[XLjedi]

Been curious about whether or not there is any reason to mount a Direct Antenna if I have a Relay Antenna on a craft?  ...is there a need for direct antennas anymore?  Or some benefit to having them vs. a relay antenna?   

 

[BRAAAP_STUTUTU]

40 minutes ago, XLjedi said:

Been curious about whether or not there is any reason to mount a Direct Antenna if I have a Relay Antenna on a craft?  ...is there a need for direct antennas anymore?  Or some benefit to having them vs. a relay antenna?   

 

EC consumption and weight, they might also transmit at a higher bandwith but im not sure about that part

[Rocket In My Pocket]

1 minute ago, BRAAAP_STUTUTU said:

EC consumption and weight, they might also transmit at a higher bandwith but im not sure about that part

This^

Also, cheaper cost wise, typically 1/2 as much for the same power.

And yes, the direct antenna do tend to transmit faster, although not in all cases.

[XLjedi]

But as far as Relay vs. Direct?  

https://wiki.kerbalspaceprogram.com/wiki/Antenna

Seems to be no reason to have a direct antenna if you have a relay antenna.  Regardless of distance, it would seem that any direct antenna will work?  Just a matter of energy usage and speed.  I'm tempted to just put the "HG-5 High Gain Antenna" on every craft and call it good.

 

Edit:  I may have answered it for myself.  Looks like there is a CommNet difficulty setting that is probably not enabled in the base game and I need to turn it on.

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

 

Edited November 24, 2018 by XLjedi

[Rocket In My Pocket]

Well the difficulty settings aren't going to change the fact that Relays are better than Direct. (They just make your Antenna/DSN stronger/weaker.) That's just how it is, the idea is that due to cost, size, and form factor; Direct are easier to use. (Ie. compare the Tier 5 Direct vs. the Tier 5 Relay as far as form factor: https://wiki.kerbalspaceprogram.com/wiki/Communotron_88-88 vs. https://wiki.kerbalspaceprogram.com/wiki/RA-100_Relay_Antenna The Direct is compact and deployable, the Relay is large and unwieldy.)

The way I look at it is that Relay's are for satellites/bases/stations who are permanent and will likely end up bouncing signals.

Direct are for mission craft, who will most likely only be around temporarily and therefore don't need a Relay as it's very unlikely they'll be needed as infrastructure, they just need signal.

Edited November 24, 2018 by Rocket In My Pocket

[XLjedi]

1 hour ago, Rocket In My Pocket said:

The way I look at it is that Relay's are for satellites/bases/stations who are permanent and will likely end up bouncing signals.

Direct are for mission craft, who will most likely only be around temporarily and therefore don't need a Relay as it's very unlikely they'll be needed as infrastructure, they just need signal.

I have a station, that is moveable...  So it's kinda like a mothership I s'pose and I was debating which it will be.

[Snark]

19 hours ago, XLjedi said:

Been curious about whether or not there is any reason to mount a Direct Antenna if I have a Relay Antenna on a craft?  ...is there a need for direct antennas anymore?  Or some benefit to having them vs. a relay antenna?  

In terms of gameplay behavior (simply on the question of "relay" versus "direct"):  No, there's no reason.  If you've got a relay antenna there, adding a direct antenna doesn't really help.  It'll boost the non-relay antenna power of the overall station (due to antenna "stacking"), but since you presumably want to use your station as a relay, that wouldn't really help you-- if you needed extra power, you'd need to stack relay antennas.

The main benefit to the direct antennas is that they tend to be 1. lighter, and 2. cheaper, and 3. physically smaller and/or more convenient and/or foldable, compared with their relay equivalents.

For example, the direct antenna Communotron 88-88 has the same antenna power as the RA-100 relay antenna.  But the relay antenna is twice the price, over six times the mass, and is a great big ungainly unfoldable solid dish, compared with the nice compact form of the 88-88 when folded.

So in general the design choice comes down to this:  Depending on the role you need for your vessel... does it need relay capability or not?  If it doesn't, then don't bother with relay antennas and load it up with direct ones, since they're cheaper, lighter, and smaller.  On the other hand, if your ship does need relay capability, then there's not really any point in putting any direct antennas on it, in most situations.

19 hours ago, BRAAAP_STUTUTU said:

EC consumption and weight, they might also transmit at a higher bandwith but im not sure about that part

Certainly weight's a lot higher for the relay antennas.  However, as far as EC consumption and bandwidth are concerned, for the most part they're roughly the same speed and power efficiency as their direct-antenna counterparts.

The one exception (and it's a huge one) is the RA-2.  For reasons I've never been able to figure out, that antenna truly sucks for transmitting science.  It's by far the slowest and most electricity-guzzling antenna in the lineup-- it needs way more electricity per science point when transmitting than anything else.  It's... freakishly inefficient, to the point that I sometimes wonder whether it was an accident or oversight on Squad's part.

18 hours ago, XLjedi said:

I'm tempted to just put the "HG-5 High Gain Antenna" on every craft and call it good.

The HG-5's a great antenna, and I like it a lot-- not least because it's the only relay antenna that's foldable and the only one that's radially attachable, which is hugely convenient feature.

However, it's only good for connectivity within a planetary system (e.g. as low-to-medium-altitude communications around Kerbin).  Its 5M antenna power isn't even vaguely strong enough for interplanetary communications.  For that, you need the next-higher tier of antenna, which is literally four hundred times more powerful.

So:  If you're sticking to Kerbin's SOI, you can get done everything you need with HG-5's, if you stack enough of them.  However, if you're leaving Kerbin to go visit other planets, you'll need something higher-level.

[bewing]

4 hours ago, Rocket In My Pocket said:

Well the difficulty settings aren't going to change the fact that Relays are better than Direct.

I'm not so sure about that.  I think XLjedi meant that he had CommNet turned *off*. With CommNet off, any antenna will do exactly the same job.

Once you turn CommNet on, then a relay antenna will do everything that a direct antenna can do, plus it will also relay. But the whole point of CommNet is that once you turn it on, you have to start worrying about how much range each antenna has, and the HG5's are pitifully short range.

 

[Rocket In My Pocket]

37 minutes ago, bewing said:

I'm not so sure about that.  I think XLjedi meant that he had CommNet turned *off*. With CommNet off, any antenna will do exactly the same job.

Once you turn CommNet on, then a relay antenna will do everything that a direct antenna can do, plus it will also relay. But the whole point of CommNet is that once you turn it on, you have to start worrying about how much range each antenna has, and the HG5's are pitifully short range.

 

Ahh, yes.

I hadn't considered he didn't turn Commnet on at all lol.

I assumed he was talking about the Difficulty slider bars.

[Tyko]

My first interplanetary probes usually have a direct antenna that will reach Kerbin and a shorter range relay antenna. After the probe completes its primary mission it gets boosted to a higher orbit and re-purposed as a local relay.

It's worthless until I get a long ranged relay established but once I do the old probe offers a cheap way to improve my radio coverage.

[Pringles01]

 

On 11/24/2018 at 10:30 AM, Rocket In My Pocket said:

Well the difficulty settings aren't going to change the fact that Relays are better than Direct. (They just make your Antenna/DSN stronger/weaker.) That's just how it is, the idea is that due to cost, size, and form factor; Direct are easier to use. (Ie. compare the Tier 5 Direct vs. the Tier 5 Relay as far as form factor: https://wiki.kerbalspaceprogram.com/wiki/Communotron_88-88 vs. https://wiki.kerbalspaceprogram.com/wiki/RA-100_Relay_Antenna The Direct is compact and deployable, the Relay is large and unwieldy.)

The way I look at it is that Relay's are for satellites/bases/stations who are permanent and will likely end up bouncing signals.

Direct are for mission craft, who will most likely only be around temporarily and therefore don't need a Relay as it's very unlikely they'll be needed as infrastructure, they just need signal.

So the take away from all of this is that Relay is for satellites and Direct is for landers? This rules that Relay is good for bouncing signals and that Direct is simply for having a good connection with KSC correct?

[Kryxal]

One thing that people haven't mentioned yet it, it's good to have a cheap direct antenna if you have a retractable relay antenna, for launch purposes.

[jimmymcgoochie]

On 5/16/2023 at 8:38 PM, Pringles01 said:

So the take away from all of this is that Relay is for satellites and Direct is for landers? This rules that Relay is good for bouncing signals and that Direct is simply for having a good connection with KSC correct?

Not necessarily, but as a general rule yes: relay dishes are bigger, heavier and more power-hungry than a direct antenna of the same transmitter power and so are better suited to orbital relays whereas things like landers and rovers would be better with a direct antenna as those are lighter, smaller and use less power. With a good relay network, you don't even need to include a transmitter on each mission that can reach all the way back to Kerbin, just one that can reach the relays that then bounce the signal home with their powerful relay dishes.

On 5/29/2023 at 5:11 PM, Kryxal said:

One thing that people haven't mentioned yet it, it's good to have a cheap direct antenna if you have a retractable relay antenna, for launch purposes.

Almost every command part (crew pod or probe core) has a built in antenna which is pretty weak but good enough for most of a launch, while a single Communotron-16S will cover you for most low orbit situations, either directly connecting to a DSN ground station or to a relay.