Posted by Faisal Shah on January 8, 2010 at 1:29pm
* 900 MHz Frequency Hopping Spread Spectrum Transceiver* Point-to-Point and Point-to-Multipoint Network Topologies* Transmitter Power Configurable from 1 mW to 1 W* RF Data Rate Configurable from 38.4 to 500 kb/s* Serial Port Rate up to 460.8 kb/s for Streaming Applications* 128-Bit AES Encryption* Separate Serial Port for Diagnostics* Analog and Digital I/O for Sensor Applications* FCC and Canadian IC Certified for Unlicensed Operationhttp://www.rfm.com/products/dnt900.shtmlIs this too good to be true? Anyone try this out yet?How does it compare to the Digi Xtend module (1W as well): http://www.digi.com/products/wireless/long-range-multipoint/xtend-module.jsp
I see by the other comments that I am three years late here but I just discovered this great site and this great product. I like the FHSS for sure but I am almost clueless as to how to use this. By "almost" I mean that I am a retired computer hardware engineer and understand quite a bit about this stuff. I would like to use this device simply for sending real-time video from my ship to the ground. As I understand it, my video must be in a digital format MPEG4 etc. I think I can handle that but programming this device will be a whole new ball of wax for me. I can probably figure it out in time. But any primer or reference material you could link me to would be of great value. Obviously if someone here has accomplished what I want to accomplish I am certainly up to plagiarizer!
I'm hoping I can adjust its frequency bands. It's capable of 902 - 928 MHz, but in NZ I'm only allowed to use 921-929 MHz at 1W, and only 3mW for the rest of that band.
I personally tested a MaxStream Xtend to 73 Miles right after they were released...
The ground station used a 14dbi dish, and the airborne part was an x-tend with a rubber duck taped to the inside window of a cessna cardinal. The ground station was set up to loop back and pointed in a fixed direction.
I flew out the direction of the antenna beam and periodically turned 90 degrees to let the side window see the beam without the tail in the way. At 73 miles I still had 100% data with no loss at 19200. I could not go farther because it worked better than I had expected and I was out of airspace to fly into. I was on the edge of the LAX Class B
Well best you test them then Andrew ;-) Wonder how the cost will pad out once you mount it in a case and put an antenna on it. But a good find none the less.
From a purely RF performance perspective it is difficult to make a direct comparison with the Digi XTend, because Digi do not provide adequate specifications (i.e receiver sensitivity at given BER and data throughput).
The fact that RFM do quote receiver sensitivity is very reassuring (-108dBm at 10-5 BER and 38.4kb/s). These numbers seem about right to me.
Comments
Greetings!
I see by the other comments that I am three years late here but I just discovered this great site and this great product. I like the FHSS for sure but I am almost clueless as to how to use this. By "almost" I mean that I am a retired computer hardware engineer and understand quite a bit about this stuff. I would like to use this device simply for sending real-time video from my ship to the ground. As I understand it, my video must be in a digital format MPEG4 etc. I think I can handle that but programming this device will be a whole new ball of wax for me. I can probably figure it out in time. But any primer or reference material you could link me to would be of great value. Obviously if someone here has accomplished what I want to accomplish I am certainly up to plagiarizer!
Might be pushing it to the absolute limit but... keep us posted!
The ground station used a 14dbi dish, and the airborne part was an x-tend with a rubber duck taped to the inside window of a cessna cardinal. The ground station was set up to loop back and pointed in a fixed direction.
I flew out the direction of the antenna beam and periodically turned 90 degrees to let the side window see the beam without the tail in the way. At 73 miles I still had 100% data with no loss at 19200. I could not go farther because it worked better than I had expected and I was out of airspace to fly into. I was on the edge of the LAX Class B
Paul
The fact that RFM do quote receiver sensitivity is very reassuring (-108dBm at 10-5 BER and 38.4kb/s). These numbers seem about right to me.
And the price is very appealing. Nice find.
Andrew.