Questions tagged [software-development]

Questions related to writing software (programming) for Amateur Radio purposes.

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1answer
40 views

How to get the “real” number of samples coming in an sdr

so I am fairly new to this SDR and dsp thing, I am working on a project that calculates the ppm and adjusts the offset, now I kinda got the idea of how to calculate the ppm after going through the ...
0
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2answers
46 views

Not able to understand some operations in rtlsdr library in python

Here is the part of the program I am having problems with: samples = sdr.read_samples(16*1024) power, _ = mlab.psd(samples, NFFT=1024, Fs=sdr.sample_rate /1e6) ...
4
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2answers
282 views

Problem with sample rate

So I am working on a project that involves me to check real time difference between samples.I am fairly new to this so after a bit of researching I wrote a simple python script for it, here is the ...
3
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1answer
65 views

How do I write a modem for DireWolf?

I was looking at the selection of modem bauds for DireWolf and it seems the highest baud modem is 9600 baud, and I am using a sound card that can reach 48 khz. Is there any way that I can write a ...
1
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0answers
32 views

Sending custom EWS over DAB+ with a HackRF One

Disclaimer: I'm aware of legal issues regarding EWS! Rest assured that there is no need for concern as this is a small-scale, proof of concept done in a controlled enviroment! Greetings! I'm trying to ...
5
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2answers
126 views

Calculating satellite passes without an internet tracker?

Situation: You want to know when a satellite will pass in order to receive an image transmission or to work an amateur satellite. However, you cannot access internet for whatever reason, and ...
1
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0answers
130 views

How to use OFDM Synch in GNU Radio?

I am transmitting OFDM 16-QAM x 6 carriers packets using the python library amodem and a HackRF. My setup is very simple for the transmission side, it takes the .wav generated by amodem from data and ...
1
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0answers
35 views

2GFSK digital filter bandwidth calculation

I'm working on a S2LP from ST and I am configuring the RX digital filter. I need to calculate the bandwidth of the signal which has 2GFSK modulation. Do you think the code below is correct for ...
3
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1answer
138 views

What is the format of Yaesu FT3D's QSOPCTDIR.dat and QSOPCTFAT.dat files?

The Yaesu FT3D can send photos, but only if taken with the optional external mic that has a camera. I want to be able to send photos that come from elsewhere, by putting them on the SD card. But it ...
3
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2answers
231 views

How do blind hams operate?

In an earlier question, there seemed to be some surprise when I (indirectly) asked about radio modes accessible to a blind operator. First question: So how do blind hams operate? If I were to be ...
3
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1answer
95 views

Turning raw APT data into an image

I apologize if this question is a little out of scope for the amateur radio stack exchange but I feel like it fit better here than over in any other forum. I have successfully parsed raw PCM data out ...
3
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0answers
58 views

What value goes in the AX.25 PID field if the Layer 3 protocol is not defined in the standard?

I am working on space-ground networking for a Cube Satellite, and one of our candidate Layer 2 protocols is AX.25. We haven't settled on a physical layer, but it's likely to be some form of quadrature-...
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0answers
86 views

Looking for a formula used by VE6YP trap calculator

I wonder whether the source code of VE6YP (Tony Field) coaxtrap design program (link 1, link 2) was ever published or described. As a Mac user I'm having little difficulties using this software and I ...
3
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4answers
527 views

Is there an FT8 or other weak-signal digital mode specification available?

Is there a complete and programming language independent specification available for the FT8 digital mode? Detailed enough to implement both transmit and receive SDR software from scratch in two ...
2
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1answer
1k views

How to trim out background noise GRC

I am creating a radio receiver to pick up "walkie talkie" chatter. success it works fine! I can hear people when they speak on the radio, the only problem i am having is that when no one is speaking ...
1
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1answer
423 views

GNU Radio code and data type conversion

I am a GNU Radio beginner, and I use the following code to make the block's output-port output a pmt data: ...
2
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1answer
649 views

USRP: Are RX and TX on the same or different channel for single daughterboard?

I've got a USRP X310, currently with just one daughterboard, a WBX-120. I'm writing some C which needs to operate the radio full duplex - I receive on RF A RX2 and transmit on RF A TX/RX. But I'm ...
2
votes
1answer
203 views

Is it possible to generate rf by directly programming a pc parallel port?

From what info I've found, it seems a pc parport has a max speed of ~2meg /sec ? So transmission on medium wave, to ~160 meters should be possible ? With antenna than possibly a small wire, I ...
2
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2answers
407 views

How link between gnuradio and baudline?

I want to create a sink block in GNU Radio which transfers the signal to baudline. My purpose is viewing SDR's received signal online. How should I program this block?
2
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1answer
465 views

How to process signals captured using a SDR?

I saw that Oona Räisänen uses C and Perl to process digital signals: https://github.com/windytan So I was wondering if there is any book (or ebook) about how to use programming to process digital ...
8
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3answers
163 views

Does LOTW have an interface document?

I want to be able to sign my own LOTW entries, without using the provided library (My application is pure Java). Is there a document that explains in enough detail how to do this, assuming of course ...