Relay Antenna Rating (Combined): At Least 5.00M????

[Xtra]

Relay Antenna Rating (Combined): At Least 5.00M????

Okay for the life of me I cannot figure out what On Kerbal, Earth, or Any other planet how to figure this out.

I have a mission - This is the Requirement.  I seriously don't Care about the Range or Distance... I want to know how to figure out the Combined Rating (CR)!!  If the CR is actually the Range or the Distance... Then I can make sense (maybe) of it.  But when I'm trying to put a SAT in orbit around the Mun with a Relay Antenna Rating of at least 5.00M... and I slam a RA-M-08 Relay Antenna Rated at 100G, then darn it, it should complete the requirement!!!  

But I sit in the VAB with Contracts open and I add antenna after antenna after antenna, all relays and it doesn't give me a check mark stating I've met the build requirements... Then I'm lost and Frustrated. 9 hrs of trying different combinations, hours of launches getting them into orbit just right only to find I for some reason Cannot combine enough antennas to meet the requirement.  This should not be this difficult... I truly want to learn but I'm not going back to learn trig all over again!  Hell I'm 60... and this is supposed to be FUN!

 

Can someone please break it down to something simple like 6 HG-32's will give you a Combined rating of ### 

I have DSN L3 stations... 

Because as I understand it... HG-32's have a Rating of 32.0M.   If I'm combining them do I divide by .75 or multiply by .75.  

Would the Combined rating of 2 of these antennas be 48.0M?                    32.0M*2*.75 = 48.0M?

I'm really surprised there isn't a spreadsheet built for building Comm Relay Satellites, where you put in the type of relay antenna, how many of each, equals combined antenna rating, max range, max distance at 100%, power Required.

These science missions aren't asking for SATs to be put in orbit combining Currently launched SATs, because then I'd be set with all the SATs I have in Orbit... 

 

Here is another example.  I have a simple probe. - I have 4 RA-002 Relay Antenna - when I check the RC-12 Remote guidance Unit - it states my CommNet Relays: 4, Rating 5.66G.   To me, that says I've met my requirement for the 5.0M combined Rating.  Am I wrong?????

 

 

Edited October 25, 2021 by Xtra

[jimmymcgoochie]

A single HG-5 has a relay rating of 5M with the default 100% antenna range modifier in your difficulty settings, however if you want that relay to actually be any use as a relay then bigger and more powerful relay dishes are recommended- if anywhere outside Kerbin’s SOI then an RA-2 is the minimum and preferably an RA-15 or RA-100.

All antennae have diminishing returns; while some mods can change this, they’ll probably say so in the part descriptions so unless you see anything there assume it’s the default 75%. Each additional relay adds (0.75^n) additional range where n is the number of extra antennae after the first (it’s a zero index as anything^0 = 1). With two identical dishes that have 32M range, you’ll get 32 + (32^0.75) = 32 + 24 = 56M total range; add a third and that one gets ((32^0.75)^0.75) = 24^0.75 = 18M additional range, and so on. You’ll quickly run into some pretty steep reductions with more dishes- the second dish adds barely half the original range, the fourth is about 0.3 times- and it quickly becomes cheaper, lighter and more efficient to add one better dish e.g. an RA-2 with a rating of 2G than stacking a load of smaller ones.

If you have antennae with different ratings, I believe it starts from the most powerful before working down to the weakest. There are a few mods out there that can help you with antenna ranges and planning, though Antenna Helper is the only one I can remember the name of right now.

 

Edited October 25, 2021 by jimmymcgoochie

[DeadJohn]

See links below for an antenna wiki, CommNet spreadsheet, and a mod that shows more antenna info.

There's more detail than you want. You don't have to keep repeating the math, but I suggest learning a bit more about how it works to understand why "combinability rating" limits the usefulness of multiple antennas.

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

 

[Xtra]

Thank you to both of you.  I've gone over the Antenna Wiki and CommNet Spreadsheet several times and it loses me.

The one thing that I'm not seeing even above is the explanation of Rating.  The mission states a Relay Antenna Rating (Combined): At Least 5.00M -   Which if I were to put two HG-32's with a range of 32.0M, does this give me a RATING of over 5.0M or just a RANGE of 56M?

That's what's messing with my mind... is Rating and Range the same thing?  I'm thinking not because it doesn't seem to complete the missions.

[jimmymcgoochie]

Rating and range are equivalent- a 5M antenna has a range of 5Mm (5 megametres, or 5000km) while a 2Gm antenna has a range of two gigametres (2 million km). If you think you’ve completed the contract, can you share a screenshot of the craft in question with the contract information panel open on the right side of the screen? You should see every parameter on the list with a green tick, if one is missing then that’s what you’re missing.