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--- communication:licence_exempt [2009/01/15 23:25] – rocketboy
+++ communication:licence_exempt [2013/04/12 20:48] (current) – External links edited geoff-g8dhe
@@ Line 3: / Line 3: @@
 There are a large number of licence exempt radio communication modules available (e.g. see link) - however there are only 3 types that may be used for air to ground communication (see link) - these are:
-  * Radio Location: 173.7 – 174 MHz and 458.9625 – 459.1000 MHz 10 mW erp 12.5 kHz or 25Khz handwidth
+  * Radio Location: 173.7 – 174 MHz and 458.9625 – 459.1000 MHz 10 mW ERP (Effective Radiated Power) 12.5 kHz or 25kHz bandwidth
-  * Data Transmission: 434.040– 434.790 MHz 10 mW erp 25 KHz bandwidth and 433.05 - 434.79 MHz 1mW erp 25Khz bandwidth
+  * Data Transmission: 434.040– 434.790 MHz 10 mW ERP 25 kHz bandwidth and 433.05 - 434.79 MHz 1mW ERP 25kHz bandwidth
-  * Video: 2.400 – 2.4835 GHz 10 mW eirp 20 MHz Bandwidth
+  * Video: 2.400 – 2.4835 GHz 10 mW EIRP (Effective Isotropic Radiated Power) 20 MHz Bandwidth
-Equipment must conform to EN 300 220
+Modules must conform to EN 300 220
-And as of Septemeber 08 - 500mw on 869.40- 869.65 MHz < 10% duty cycle
+And as of September 08 - 500mw on 869.40- 869.65 MHz < 10% duty cycle
-Given the very low powers (10mW is about the power used by a dim LED)- its going to take some doing to use these in balloon to ground communication.
+Given the very low powers (10mW is about the power used by a dim LED)- its going to take some doing to use these in balloon to ground communication - but it can be done - over 400Km has been achieved.
+Below is an example of a 10mW NBFM (Narrowband FM) transmitter module for use at 434.650MHz.
+{{communication:radiometrix_ntx2-434.650-10_full.jpg?200|Radiometrix NTX2}}
+The [[http://www.radiometrix.com/|Radiometrix NTX2]] is the module of choice for UK HABing.
 ===== External links =====
-  * http://www.ofcom.org.uk/radiocomms/ifi/tech/interface_req/msoC4784.pdf
+  * http://stakeholders.ofcom.org.uk/spectrum/information/licence-exempt-radio-use/licence-exempt-devices/short-range-devices-information - Useful Ofcom Short Range Devices Information Sheet
+  * http://stakeholders.ofcom.org.uk/binaries/spectrum/spectrum-policy-area/spectrum-management/research-guidelines-tech-info/interface-requirements/IR_2030.pdf - The full requirements document.
   * http://www.rfsolutions.co.uk/acatalog/index.html