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| Radio Direction Finding |
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| oe6rke:
Hi Lodewijk, first of all cudos und big thanks for your software and work you put into. With help of this software we are enabled to narrow down some qrm on local repeaters. Using primary this software and setup in a mobile configuration we experianced some issues, which would be cool to have within the software. 1) i identified, that selectivity in notebooks sound cards are pretty poor. especially on weak signals the trigger sinus wave is recognized also on the other channel. This produces wrong bearings to sort out. A big help would be being able to select two soundcards (one for rig audio and another the trigger) or having both on one channel (checkbox selection would be fine) 2) often craft builders are not capable to differ beween clock counter wise and reverse ;). A checkbox regarding that would be also very handy 3) wavelog creation is something fine, but its hard to relate them to postion and time. Therefor a general log with dde current gps, currently save wav filename and datetime would be a cool thing. If this would be a peramanent log with adding data always at the last would be perfect. This helps to analysis data afterwards 4) some replay feature would be cool, especially playing with some parameters could bring out more results ;) so i hope ;) big wishes, but all generated from practical usecases :). if i can give you a helping hand on coding vb please le me know. to contribute and not just taking from the project would be highly appreciated by me. pse drop me a line if you like. thanks again for the software, 73 de oe6rke, ciao Robert |
| KD0CAC John:
How much of an issue would it be to use / modify for many bands ? Being a ham , the 1st thing for me would be for RF in the area that is causing issues , bad power-line transformers , insulators etc. Then as a 2nd , [ but as soon as I had something like this , it would create its own demand ] deliberate interference . Thanks John |
| oe6rke:
the qrm i mentioned is man made. in other words i an unknown person bothering and insulting hams on the repeater. this is pretty bad and authorities and hams too are already on the seek mission for that person ... |
| PA3BNX:
Hello Every Body, I see some have troubles with separation of left and right channels in software. Well let me say this you need a stereo soundcard on the inputs. Many laptop soundcards are just stereo output and have one mono microphone input. That's not okay for my application ! You can however take a USB stereo input soundcard. with 2 line inputs. Separating the reference input on one soundcard and audio input on another is not possible because the left and right input needs to be taken in one conversion So a soundcard has one digital sampled word with two channels in it. My software uses a double word for both channels and then separate that in left and Right channel so low-byte and high-byte The two 8 bit channels can vary between 0 and 255 so 127 is the zero line of the audio. This makes sure the audio sample and reference audio sample are exact taken on the same time. You need not to have a good sound card just an ordinary one is okay with 16 bits and 22kHz is enough. You can hear the reference on the right speaker and the audio on the left pc speaker You can off course set the balance to the left so you only hear the audio from the FM reciever through the pc speakers. New info: I am still working on the kml logging option for Google_Earth in SoundDoppler.exe It is still not ready as is wished I am also working on a SoundDopplerNet.exe program in VB 2005 SoundDoppler119.exe and gps112.exe are in good old VB6 Let me now if you want to help programming on SoundDopplerNet.exe |
| PA3BNX:
Hello Every Body, I think my software has possibilities to save the audio in a wav files with name that contains heading quality time and data All squelch controlled by squelch from rig or squelch from dopplertone A CW or CCW option is includes it's called 0 /180 degrees. It has a waterfall and SCF scoop to see the quality of the dopplertone. It has also a Scoop screen with left and right audio lines. Some Window Versions have a error in the winmm.dll Then the left and right channel are changed. You can by clicking on the do events label The numbers under the Freq and Dcd checkbox reset the soundcard buffer of winmm.dll pointer The label Will be yellow for a moment So the reference is again up in upper line of the inputXY scoop. The frequency range of the antenna is as follows The diagonal distance must be smaller then .35 lambda of the working frequency because otherwise you Will get ambiguity Of course you must adjust the length of the whips to about .25 lambda of the receiving wave length. That's not critical at all is even quite good if the are not all 4 same length. but vary a bit in length so they do not resonate and influence each other fields. In general with about diagonal 34 cm apart you can easy do 2 meters and 70 cm Just put on some shorter whips for 70 cm. |
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