I worked with DAB and noticed that some frequencies were not correct. I've imported data from http://www.wohnort.org/dab/freqs.html, which is a reliable source that I've used in the past.
Added a PRESETS.TXT file (inside /LOOKINGGLASS folder).
Also optimized the way the spectrum signal is integrated into the cascade.
Added provision for ranges lower than 240MHz but I am afraid that at this time it will not be advisable to lower ranges any more than 240MHz, since some artifacts and frequency running - moving out of place- occurs.
I can only hope that someone with a better understanding of hackrf's inner code can fix this issue and perhaps enhance the scanning speed.
I found some "original commenting" inside the code:
// TODO: Move more low-level radio control stuff to M4. It'll enable tighter
// synchronization for things like wideband (sweeping) spectrum analysis, and
// protocols that need quick RX/TX turn-around.
Which makes me think that there are things "missing" from the portapack side of the code, for allowing serious speed sweeping. So I am concluding that with current "portapack framework" this might be "the best possible thing".
It is to be noted that the "new" internal sweep mode code is signed by:
* Copyright 2016 Mike Walters, Dominic Spill
*
* This file is part of HackRF.
Maybe Mike or Dominic can be contacted and hopefully lend a hand on enhancing this code.
It reads the antennas definition from a txt file:
WHIPCALC/ANTENNAS.TXT
Inside the textfile you place each antenna you own with the following sintaxis:
<antenna label> <elements length in mm, separated by a space>
For example:
ANT500 185 315 450 586 724 862
Input the required frequency, adjust the wave type (full / half / quarter, etc.) and the calculator will return the antenna length (metric and imperial) while also calculating how much you need to expand the fitting antennas you got defined on the txt.
It may return up to 8 matching antennas, which is more than enough (normally you will have 2, perhaps 3 telescopic antennas around for your portapack)
If by any chance your antennas txt got more than 8 antennas, and more than 8 matches the length of the freq / wave you want, it will only show the first 8 matching antennas and will warn you at the bottom that there are even more results (hidden).
All calculations now are rounded into the best integer, considering first decimal, so precision is double than the original antenna calculator app.
