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diff --git a/gr-uhd/apps/hf_explorer/hfx_help b/gr-uhd/apps/hf_explorer/hfx_help new file mode 100644 index 000000000..9a52dd2bb --- /dev/null +++ b/gr-uhd/apps/hf_explorer/hfx_help @@ -0,0 +1,180 @@ + + HF Explorer Help + + ----------------------------------------------------------------------- + + Command Line Switches: + + -c DDC center frequency, set band. + -c 7.2e6 or -c 7.2M for 40 meter ham band. + Default is 3.9e6 80 meter ham band. + Example: + + hfx.py -c 9500k + + starts up in the 31 meter band. + + -a Audio output file. Output file for 32kHz two channel + signed word audio. Two channels are used for + independent sideband. This file can be converted + to a wav file with sox. Example: + + sox -c 2 -r 3200 file.sw file.wav + + sox needs the .sw extension to indicate file type. + If not specified no audio file is created. + + -r Radio output file. File to write RF data to for later + demodulation. Records the entire band to disk, width + determined by sample rate/decimation. Be sure to + note the decimation and center freq for later use! + Example: + + hfx.py -c 900e3 -d 80 -r rf_data_AM-c900e3-d80 + + writes a pre-demod rf file centered on 900kHz with a + bandwidth of 800kHz (That's 80 AM stations!). The + center and decimation could be put in the filename for + proper use later. + If not specified no rf data file is created. + At default 250 decimation disk usage is about + 8Gb / hour. + + -i Radio input file. Use to play back a previously + recorded rf data file. Example: + + hfx.py -c 900e3 -d 80 -i rf_data_AM-c900e3-d80 + + plays back the previously recorded band, no + usrp hardware needed. Tune about the 800kHz wide band. + When playing a recorded file, time controls + fast-forward and rewind are available. + + -d Decimation. Sets sample rate and bandwidth. + This is the factor that the usrp sample rate, 64e6, + is divided by. Default is 250 for 256kHz bandwidth + which is enough to record a ham band without + eating up disk space too fast. The 64e6 sample + rate limits the upper practical frequency to 32MHz. + The Basic RX transformer limits the lower frequency + to about 200kHz. + + + Powermate Knob: + + A Powermate knob is recommended but not necessary. If a knob + is used, it is in one of 3 or 4 modes controlling frequency, + volume, filter and (if playing a recorded file) time. + Pushing the knob switches mode and the buttons on the HFX panel + change to show which mode is in effect. Then just turn the knob + to set frequency, volume, filter or go fast forward or rewind. + + + Bandswitch: + + Across the top are a set of predefined bands and buttons + to rapidly switch to the center of that band. To change a band, + type the frequency in Hz into the box under "Center Frequency", + then press "Set" on the left, then the button you want to + program. From then on (untill the program is exited) pushing + that button takes you to that band. To make a band button + permenant edit the hfx.py script with whatever frequency you + want assigned to what button. + + + Frequency: + + There are 6 ways to set the frequency. + 1) Move the slider with the mouse + 2) Use the Spin Control up/down arrows (very fine 1Hz control) + 3) Type the frequency in Hz into the Spin Control + 4) Turn the Powermate knob + 5) Web control. + 6) Clicking on the FFT display to set demod center. This is very + convenient for tuning +-15kHz when you see a signal on the + display. If in Lower Sideband, clicking just to the right of + a signal will tune to it immediately. Clicking several times + on the far right right or left of the display will rapidly + tune up or down the band. + + + Volume: + + Move the volume slider with the mouse, or push the Powermate knob + untill the volume button is active, or click on the volume button, + then turn the knob. Volume can also be set by web control if web + control is setup and enabled. + + + Filter: + + Similar to volume, switches in any of 30 audio filters from 600 + to 3600Hz in Sideband or up to 5kHz in AM. + + + Mode: + + Demodulation modes are chosen by clicking on the buttons for + Lower Sideband, Upper Sideband, or AM. + + + PGA: + + PGA slider sets the rf gain in the Analog-to-Digital converter + before digitizing. 0 to 20db gain easily shows up on the FFT + display. + + + Time: + + When playing back a recorded RF data file, you can enjoy the + freedom of rewinding or fast-forwarding. Replay a weak signal + or skip through annoying AM commercials. + + + Antennas and Preamps: + + The USRP Basic RX board is not sensitive enough for anything but + the strongest signals. In my experience about 40 db of small + signal gain is required to make the HFX as sensitive as other + receivers. Some working amplifiers are the Ramsey PR-2 with 20db + gain, fairly low noise and more bandwidth than we can use here. + Also the amp modules from Advanced Receiver Research are nice. + I use an ARR 7-7.4MHz GaAsFET 29db amp with .5db noise at the + apex of a 40 meter dipole with excellent results. Another + amp I like is a Minicircuits ZHL-32A 29db amp but they are + expensive and hard to find. Also it may help to use some filters + to keep strong local signals from the ADC, or limit rf input + to the band of interest, etc. + Resonant outdoor antennas, like a dipole, in a low-noise (away + from consumer electronics) environment are nice. Long random wires + with a tuner work. I like a small indoor tuned loop made from 10ft + of 1/4" copper tube, a 365pf tuning cap and a pickup loop connected + to rg-58. + + + Web Control: + + To control your radio remotely, ensure you have a web server + (Apache, etc) working and a compatible directory structure in + place. Directories /var/www/cgi-bin/commands and + /var/www/cgi-bin/state must already exist. You will need a + home page with forms and a set of scripts to put commands in + and put the current state on the home page. email me for further + help. Setting WEB_CONTROL to True in hfx.py turns on the timers + that check for commands and update the state. + + + IF Output: + + There is a provision for outputting un-demodulated complex + through the audio out in stereo for use with Digital Radio + Mondial (DRM) or using a seperate demodulation program like + SDRadio (by I2PHD). + Set IF_OUTPUT to True in weaver_isb_am1_usrp4.py. + + + --Good luck and happy LW/MW/SW Exploring. + Chuck + chuckek@musicriver.homeunix.com + |