RealAntennas Information

Make sure you've skimmed the RealAntennas readme first.

User Manual

1. To enable the antenna planner, find the "Antenna Planning" button, enable that, then select the "Antenna Planning GUI" button to select what body you want to plan for (relative to Deep Space Network stations on Earth).

2. Keep an eye on the gain. Higher is better, and means more efficient conversion of electricity into radio waves going towards the target.

3. The transmit power slider (and resulting Transmitter Power figure in Watts) is how much power you're pumping into radio waves. More power can improve signal strength, but costs more electricity.

4. The tech level slider should be left at maximum available; this reduces inefficiency (measured as power consumption minus transmitter power). Unfortunately, right now you need to go to the R&D center, right-click on RA tech level upgrades, and purchase them from there, despite the fact that it doesn't seem to deduct any money.

5. The RF band refers to what frequency of radio waves you're using. There are tradeoffs here. UHF and VHF are present at all ground stations (not just the DSN stations), and cap out at 50 kbps. S, X, and K bands are (currently) only available at Canberra in Australia, Madrid in Spain, and Goldstone in California, but can be substantially more power-efficient, and cap out at 330 kbps, 1360 kbps, and 20000 kbps, respectively.

6. Don't try VHF/UHF dishes. They just wind up being terrible omnis, inferior to the cheaper, lighter Communotron 16.

7. Wider-diameter dishes operating at higher-frequency bands (K > X > S) have superior gain at the cost of a narrower transmission cone.

8. Higher-tech-level antennas can do more rate halvings. Each rate halving lets you extend your range at the cost of bandwidth. This is how New Horizon's X-band dish could have 38 kb/s at Jupiter, but a mere 1 kb/s at Pluto. Note that, at least with Kerbalism, some of the higher-tech experiments can take a long time to transmit back home if you have a low bandwidth, very analogous to how New Horizons took a year to download all its Pluto flyby data back to Earth.

Key Figures:

1. Gain (in dBi). This describes the efficiency of converting input power into radio waves going in a particular direction. This ranges from about 1.5-3.0 dBi for omnidirectionals. For dishes: operating in higher-frequency bands (S, X, K) and having a larger diameter both improve gain while decreasing beamwidth (angle).

2. Transmitter power. This depends wholly on the selected "Transmit Power (dBm)" slider, and represents how much signal is actually going into space. Whether another antenna is in theoretical range of you depends on gain, transmitter power, and possibly receiver temperature (currently not implemented).

3. Power consumption. This is your active power consumption. This linearly scales with transmitter power, and goes down as tech level improves. Power consumption minus transmitter power tells you how much electricity is being wasted by inefficiencies in antenna design.

4. Idle power consumption is currently not listed, and is currently set to 10% of power consumption. This is overly generous for early antennas, and is liable to go way up in future releases.

5. Planning Result: Gives bandwidth in the selected conditions. This is how many bytes of data can be downlinked to a ground station at ideal alignment, and is the same concept as your Internet bandwidth. For Earth, you get to select a planning altitude (in Mm); the Moon is at about 400 Mm. For other planets, you just see a max and min, referring to bandwidth at closest Earth-body approach, and bandwidth at their most distant. This is going to vary most substantially for Mars and Venus.