Am mode

[victor]

hi, anyone knows if a RD6000 super is capable of AM mode?



victor

[Mathieu]

It is not

[Brandon Chng]

could someone explain why cars and some boats run off AM, while planes do FM and PCM? why does radio transmit mainly in FM not AM?

[Mathieu]

A very nice, illustrated explanation can be found at www.howstuffworks.com its very intersting..

[9VDXN]

AM = Amplitude modulation
FM = Frequency modulation

They both different modes of radio transmission.
In FM transmission, you generally need high tx power to attain the range.
FM is split into two categories.....Narrow Band and Wide band....generally, the radio stations u listen (93.3FM, 98.7, 95.0) are all wide band FM....

The TX we are using are narrow band, so that we can have many different channels in the same band....simple test to show this.....in FM wide band, even if you tune to 95.2, you can still hear a bit of 95.0 transmission. In narrow FM transmission, you can only hear the transmission at the spot-on frequency.


In AM transmission, there are a few other modulation methods: single/upper/lower side band (SSB, USB/LSB, AM)

AM is still being used widely, and advantages is the range, and high immunity to noise interference.

Since u've been to flight lessons, you should know that vox radios use AM transmission. If I recall correctly, NAV Radio/radio beacons also uses AM transmission.


As for your question on car/boat/surface models, the main reason why the use AM is because it's cheaper and mostly, they dun need the reliability. Most car enthusiast are using FM or even PCM too....

[9VDXN]

Moreover, since FM carries more 'data' or bandwidth, it can carry more signal, thus allowing more channels. If you noticed, all AM tx are 2ch models, and only FM TX are 3channels and above.....

PCM can handle more data/channels because the info that was sent over the airwaves are being encoded and sent in Packets, just like transferring data over the internet....these encrypted data are then being decoded by the PCM receiver and translated back into electrical volts and command data for the servos.

You can also technically call PCM tx & rx a MODEM....which is also known as a Modulator/Demodulator.



Hope this helps...

[Brandon Chng]

wow nice one dixon

[9VDXN]

No problems....