hamradio station pa2eon

Aug 27

Raspberry PI as ATV testscreen modulator

Today I updated the Raspberry PI as an ATV testscreen ‘modulator’.
The designer of this solution you can find at the website of PA3BWE.
In this log, I will show the mods, and the short (new) installation options.


Start with the install of the latest Raspberry OS ( you can find on raspberrypi.org)
In this OS, you will find the python and python-pygame we need for the graphics.

The basic commands:
apt-get update

* Get the ‘atv3.py’ from the website of PA3BWE
* Place this file in the folder you want to use (mkdir /home/pi/atv)
* wget http://www.pa2eon.nl/download/atv.tar
* Make two folders extra
mkdir /home/pi/atv/images
mkdir /home/pi/atv/sounds
* In the images directory you can place about 12 files with a resolution of 768 x 576 pixels.
* In the sound  directory you place the *.wav file you like ( the ‘test-beep’ ..)
* In the directory /home/pi give the command tar xvf atv.tar


To use the RCA connector (to place the right video signal to your ATV hardware) you have make an config.txt file.
This file you have to place in the /Boot folder of the Raspberry.
The next lines are important to change;
overscan_bottom=-15 # To change if characters drop the screen in bottom
After reboot of the py, give the command: sudo python atv3.py

In the download section of this site .. you will find the used file by myself ( and PA3BWE !).
The software will generate a test-sound signal (440 Hz ?).
To give options on the screen use the next keys:
I: toggle internal generated picture (default on)
R: toggle random picture mode (default off)
S: toggle sound on/off (default on)
T: toggle floating text on display (default off)
Q or ESC to end program
F1-F12 selects user-defined images (image1.jpg to image12.jpg)
The picture shows the old (green) computer screen, with the RCA active and nice test screen.
Testscreen old wayTest screen oldway 2 Basic text








The next weeks I will try to make an *.py program where the ‘graphics’ are generated by the application itself. The pictures shows the original file, and if you want to give more text you are not free to do that. The third picture is the graphic made by the application (atv3.py), very basic but useful !

Note: To test the status off the picture generated by the Pi, give the command; /opt/vc/bin/tvservice -s

May 26

CAT & Audio interface for FT-897

On the internet you will find a lot of schemas for CAT & Audio interfaces.
In this post you can see the result of the interface on a standard euro PCB board.
With the ‘diylc’ software I had made a PCB design to reproduce the schema.

The nice alu-case (part number: ADG-D105.30.160) and the audio trafos (part number: P1200) you can get at Funk-Amateur web-shop in Germany.

The two cables to connect from the interface to the RIG are one old PC-keyboard cable and the other an connector cable for macintosh computers. The audio cables I had made from an single computer audio cable with mini-din connectors, who you can find in any computer shop. The RS232 is a standard cable (9 pins).

The software to connect the computer on the RIG is in my case the Ham Radio Deluxe.
When you use the correct jumpers, you can use every kind o (small) management software you can find on the internet. You have to test the best positions ( RTS / DCD etc.)

In the download section you will find the corrsponding PCB file.
The basic schema I found on the internet, I had made a few changes (ID LED etc.)

CAT FT-897In box CATFT897

Apr 14

Build SDR radio with DR2B from YU1LM

In this post I will show the steps I had made to build the DR2B SDR receiver hardware from the OM YU1LM.
The main reason to build / use this small part of hardware is to use it as an IF monitor for my FT-736 and FT-897d Transceiver(s). The fixed MF input from the FT Transceivers will give 15 Khz and xx kHz bandwidth to help decoding the Cubesats in the 2m and 70 cm frequencies.

Here you can see the results first in a few steps.
When you follow this blog, the next days you can read and download the schema in the download section.
In the bottom of this article I will give the links I used to build the hardware together.










The Local Oscillator I used is the design from SDR-Kids.net with the Silicon Labs Chip SI570 to handle the correct frequency via the USB port of the computer.
The wooden base is a ‘new’ idea to test the design and make the correct connections to show how an SDR receiver can work.
The first tests with the SDR software and a good (stereo) microphone input in the computer are great! Now I will start to make the IF connection in the FT-736 Transceiver, that MOD will shown in a next post.

Jan 09

Rotor AC Interface & managed by PC

The DIY rotor interface is ready.
The rotor interface is connected to the PC via USB and will use the standard Yaesu GS232 protocol.
You can move the antenna rotor by hand via the ‘joystick’ and via the software on the PC.
In the download section you will find (asap) the complete building manual.

Credits are going to OM PD5DJ (Bjorn) he is the brain behind this design!
At his site you can more information about this project – info on PD5DJ website

The picture you see here are made from the hardware who I had build.
If you have questions about this project, use the contact page on this site.

Prepare the boxRotor connectorsInternal finished

Dec 24

with RTL-SDR and LNA receive cubesats

The last days I’am active with the modifications of the RTL-SDR dongle to receive the Cubesats.
In short I had used the next mods (1st test fase);

* 10 meter RG58 in coil arround the RTL-dongle to reduce noise and grounded to the USB.
* removed the metal part on the USB connector.
* added a ring-coil arround the small cable to reduce noise.
* added the LNA from lna4all (ln4all.blogspot.nl)

I’ve tested a few SDR applications, but the best results I getwas with the SDR-Console v2.1 beta software and for the RTL dongle the Ezcap USB 2.0 driver. The OS is Windows XP (now Windows 7 Pro) and running on a portable/fixed computer.
The next days I will bring the SDR-dongle together with the LNA in a metal box, to reduce more unwanted noise (shown on the last photo).

The picture(s) below will give you a nice view how I made it together.
If you need more technical information, pse send me a request (see contact page).
ASAP I will make more information available with weblinks,(sound) files and screendumps.

(pic 1. The mods)     (pic 2. Delfi-n3xt)      (Pic 3. SDR mod RF closed box)


Oct 31

Receive CQ from ISS Space Centre

Today I received the ISS ‘loud and clear’ – 59+ on the 145.800 Mhz.
I have tried to make contact back, but the TX was active on the wrong frequency, it should be 145.200 Mhz. If you want to listen to it, click on the sound-link.

Recorded CQ from ISS dd:311013 (wav-file)

Sep 25

RTL-SDR dongle and Raspberry Pi 512 Mb

Today finished the soft- and hardware solution with the RTL-SDR and RPi.
The main idea is to use the low-cost ($25) RTL-SDR dongle on the RPi and connect the RPi with a portable computer, with the SDR-client software on it.
The test antenna is the 3-element HB9CV antenna only for 144-146 Mhz.
This means that for ‘satcomm’ we can only follow the 2m oriented sats.
The RPi is the 512 Mb internal memory ‘hardware’, this should be fast enough to handle the RTL_TCP server software.
In the download section you can find the (english / dutch) manual to install the correct software on the RPi and the PC with minimum OS, Windows XP.
The pictures will show the first tests and the basic hardware.

SDR software, main screenServer (CLI) screen on Raspberry - connected to the SDR client

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