I have enabled the direct sampling option to the rtl_tcp. I would like to
submit it as a PR but I need authorization. How do we get authorization?
Thanks,
Richard Frye
Dear Steve,
Could you give a note if there is still work in progress for a linux fix?
I noticed I am affected by this on 5.2, and the last message I find
about this is yours on the arm-kernel list dating back to 9 Nov 2018.
Thanks,
Nuno
I've been studying the rtl_adsb.c code and it's very interesting how it
works..
But, I have question.
I noticed that if I request verbose output using the "-V" option, then the
CRC is printed out. But, it doesn't look like the code actually does any
Reed-Soloman error correction to the data the ADS-B specification
documents.
Am I reading this correctly?
Thanks.
-brad w.
Fix memory leak in librtlsdr.
The problem came up when using rtlsdr_open() twice with the same index.
The variable dev->devh is never cleaned if libusb_claim_interface() fails.
This causes a leak if the device is already claimed by another handle.
rtlsdr_close() did not free that space since the returned handle is invalid
if libusb_claim_interface fails
Here is the patch file in text format. (it is also joined to this email).
~~~~
diff --git a/src/librtlsdr.c b/src/librtlsdr.c
index a71609b..89ec903 100644
--- a/src/librtlsdr.c
+++ b/src/librtlsdr.c
@@ -1520,10 +1520,6 @@ int rtlsdr_open(rtlsdr_dev_t **out_dev, uint32_t
index)
r = libusb_claim_interface(dev->devh, 0);
if (r < 0) {
fprintf(stderr, "usb_claim_interface error %d\n", r);
- if (dev)
- {
- libusb_close(dev->devh);
- }
goto err;
}
~~~~
-Vincent Perrier
In RTL_SDR, option -b
What does:
"output_block_size (default 16*16384)" mean?
I have been searching and I just can't find that explained anywhere.
Thanks,
Pete
And another thing - the configuration demonstrated on the image you
provided is an actual Π (pi) type low pass filter composed by R-L-R
elements.
There, the individual resistor is 150 ohm, in DC they are parallel, in RF
they make a low pass filter along with the coil in btw.
Some implementations do not use any coil but a 0-ohm shunt resistor
instead. That means the resistors are parallel and they yield 75 ohms.
Cheers
On Sat, 25 May 2019 at 16:10, Ioannis Makris <makrisj(a)gmail.com> wrote:
> I mean that each RGB analog output of the FL2k on the PCB has permanent
> fixed terminations of 150 ohm. Still, I need to apologise for having to add
> a correction:
>
> Some of the dongles having only analog output are being terminated @ 75
> ohms at the factory.
>
> Ref.1: http://www.marsport.org.uk/smd/mainframe.htm
> Ref.2: See attached image
>
> This is normal. Those outputs are most probably open emitter outputs;
> hence they need a termination in order to actually produce any current.
> Leaving them floating in DC would most probably lead to unexpected and
> unaccounted for results.
> One could experiment by adding different values for termination or even a
> 330 ohms trimmer in rheostat configuration,while maintaining at least an 75
> ohms resistor in series so as to give a range of 75-405 ohms of
> termination.
> What is to be monitored is the actual spectral behavior of the DAC rather
> its maximum output, as there are unwanted spectral elements that could
> register as power output on the wanted frequency in conventional needle
> meters, when it actually that is far from truth.
> Affecting terminations yields intermodulation in amplifiers and unwanted
> spectral elements may occur due to several effects I can think of.
> Always monitor spectral output if you want to transmit with this thing.
> What I've seen is that if you just add 20dB of gain on its output without
> applying heavy filtering beforehand you could easily end up to jail for
> interfering aviation frequencies used at airports nearby.
>
