Comments

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  Warren Eather March 13, 2015 at 2:54am

  I believe you'll find that the range for 433Mhz@25mW is about the same as 913Mhz@100mW the signal strength and propagation loss for the 913 is about 6db greater than the 433.
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  Justin L March 13, 2015 at 2:44am

  My mate runs the 433. The antennas that came standard with it were actually 2.4 Changed them over to some decent 433 ones and now the range could easly go out of sight. The standard 915 easy goes a few km without gropping below 90%. The rfd900 on the other hand would go 20+km easy at 98% with a decent yagi / tracker setup (if we were allowed to fly that far)
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  Adam Warburton March 13, 2015 at 2:01am

  I agree technically 433MHz would be slightly better at not being blocked by obstructions (and only slightly), but it is only legal to use up to a power of 25mW without an amateur radio license, so you would have to change the settings on the radios to throttle back to 25% of their full power. Whereas the 915MHz can be used at their full power and not even come close to the max power allowed to be used.
• mP1 March 13, 2015 at 1:19am

  @Dani

  From a purely technical perspective theres no reason to chose 915 over 433. The lower the freq the more range and penetration thru objects. Given 433 is also legal in oz, why would anyone pick 915 here ?
• Dani March 13, 2015 at 12:23am

  915 MHz it is, then :)
• Felixrising March 12, 2015 at 2:35pm

  Heh... What Adam said :p
• Felixrising March 12, 2015 at 2:32pm

  @Hotwire, that i just not true - check your facts. 915-928MHz band is covered by the LIPD Class License 2000 of the 1992 Telecommunications Act. The only overlap here is with ISM devices (ie. non telecommunications uses). 915-928MHz may be used by Frequency hopping transmitters up to 1Watt (Paragraph 52).
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  Adam Warburton March 12, 2015 at 2:29pm

  Sorry "item number " not article number :/
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  Adam Warburton March 12, 2015 at 2:26pm

  Yes certain types of transmitters are used for 3G on this band, HOWEVER Frequency hopping transmitters may be used between the frequencies of 915-928 up to 1W of power as long as at least 20 hopping frequencies are used. Both the 3DR radios and the RFD900's fall into this category.

  this is outlined in article 52 in this Gov regulation document: http://www.comlaw.gov.au/Details/F2011C00543

  which is why companies selling items such as this can claim it can be used license free in Australia:

  http://store.rfdesign.com.au/rfd-900p-modem/

  Whereas the only provisioned use of 433mhz is up to the power of 25mW for any type of transmitter unless you hold an amateur radio license.
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  Hotwire March 12, 2015 at 1:49pm

  915MHz is used for the 3G phone network in Australia. It has no legal threshold and you will get fined if you get caught. 433MHz is mixed use with threshold restrictions and is legal for this kind if stuff. 433Mhz has better qualities for telemetry.