Comments

• Tim March 16, 2015 at 10:42pm

  At the risk of sounding smug, that ACMA document is precisely the one I linked to previously...

  Warren, your EIRP point is a very pertinent one. However for the 3DR radios at least, they max out at 20 dBm which is far below the 30 dBm threshold with a vanilla setup.
• Developer

  Bill Bonney March 16, 2015 at 10:42pm

  @Mitchell Berry: Radio Amateur take undertake study of how radio transmission work. How to build antenna and how to detect and mitigate the reception and the transmission of radio waves on unwanted frequencies (interference). Due to this expert knowledge they are allowed to do more with more power. 

  They still have a non-commercial license, and the expectation to help with communications in emergency situations.
• Mitchell Berry March 16, 2015 at 9:53pm

  Supposedly you are allowed much more power from 433MHz with an amateur radio license.

  I can't actually work out what a licensed radio operator does that makes them more capable of using that band? Is there some sort of CB frequency to announce your intentions to other people around? Doesn't make any sense to me.
• 

  Warren Eather March 16, 2015 at 9:35pm

  Thanks Hotwire, that's a good document.
  It's important to note that the maximum power stated refers to the Equivalent isotropically radiated power EIRP, that is transmitter power + antenna gain and not just the transmitter power.
  So for example if you had your RFD900 and a 3db antenna the maximum transmitter power setting to achieve a EIRP of 1W or 30dBm would be 30dbm-3db= 27dbm = 500mw that's half power!!
• 

  Hotwire March 16, 2015 at 2:55pm

  I have written to ACMA and I'm happy to concede I am wrong.

  Attached is the document that ACMA sent to me. It contains schedule 1 radio users regulations and is most likely what you have already referenced or a derivative.

  Thanks Mitchell & Tim. Ego bent but not broken.

  LIPD.pdf
• 

  Duncan Greer March 15, 2015 at 1:27pm

  Its worth noting that the band in Australia is 915 to 928 MHz, as opposed to North america where the band is 902-928 MHz.. perhaps this is where the confusion is coming from??  
• Mitchell Berry March 15, 2015 at 12:32am

  I'm amazed you keep persisting Hotwire, despite so much evidence to the contrary. Tim's link has the actual legislation regarding transmitter power, the law is a much more complicated than your pdf overview.

  Item 52 explicitly says 1W of power at 915 MHz if there is a minimum of 20 hopping frequencies.  

  Item 17 says a max of 25mW for 433Mhz

  52

  Frequency hopping transmitters

  915–928

  1 W

  A minimum of 20 hopping frequencies must be used.

  17

  All transmitters

  433.05–434.79

  25 mW

  The 3DR Radio regulations page says the same and provides settings for telemetry radios used in Australia to comply with these standards. 

  http://copter.ardupilot.com/wiki/common-optional-hardware/common-te...

  Australia	3DR 900	MIN_FREQ: 915000 MAX_FREQ: 928000 NUM_CHANNELS>=20	LIPD-2000 item 52
  Australia	3DR 433	MIN_FREQ: 433050 MAX_FREQ: 434790 TXPOWER<=14	LIPD-2000 item 17
• Tim March 15, 2015 at 12:15am

  That's a very pretty way of proving my point. Thank you.
• 

  Hotwire March 14, 2015 at 11:51pm

  Follow the link and know the spectrum HERE
• Tim March 14, 2015 at 4:20pm

  @Dani

  Yes - 915 is the best solution for Australia.