[QLD] Airwave Solutions Ergon Energy P25 System

techman
Posts: 42
Joined: Fri Dec 27, 2013 9:36 pm

Re: [QLD] Airwave Solutions Ergon Energy P25 System

Post by techman » Sat Oct 11, 2014 9:00 pm

citabria wrote:Hi techman,

The RTL sticks are always off - the onboard clock's resonator is usually in the order of 50-100ppm out. If you run up SDR Sharp with the dongle, you can calculate the offset correction factor quite easily, then enter this value into Unitrunker under the Control > Correction field. This will then let you tune up the RTL using the correct frequencies.

I found one of my sticks is +6ppm out, so I was lucky. Also you will find the error gets worse as you go up in frequency as the base clock gets multiplied up, so does the error.

Cheers,
Matt
I had time today to setup another sdr stick the test equipment and they do very (some bands quite a bit) away from the desired freq. Then it is a $20 stick and once you understand the limitations etc they are still good fun to play with. I'm now starting to look at other solutions like hackrf.

cheers
a
Don't like it, either get over it or retire

matthewn1983
Posts: 1532
Joined: Sat Feb 06, 2010 9:41 am

Re: [QLD] Airwave Solutions Ergon Energy P25 System

Post by matthewn1983 » Sat Oct 11, 2014 9:28 pm

I guess its gets a bit off topic here, but with my SDR, I try and use a few known frequencies as a guide, and shift accordingly - for instance at the moment on one of the sticks here, 492.5750 is being shifted -60,000 on SDRSharp. but a little lower down at 468mhz its -56,000.

techman
Posts: 42
Joined: Fri Dec 27, 2013 9:36 pm

Re: [QLD] Airwave Solutions Ergon Energy P25 System

Post by techman » Sun Oct 12, 2014 11:46 am

Yes we are a little off topic atm, I have not found any other local sites to which I visability of for Ergon in Cairns from the side where the sdr is at, I'm not sure if this is becuase they are testing or the network is still in buildout mode. Site is not peering at this point either.
Don't like it, either get over it or retire

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