➔ Decoding High Altitude Balloon Pictures
| 3 minute read
Today I experimented with reception of images from a high altitude balloon that has been started a few kilometres away. From the information beforehand I learned that it transmitted live pictures and APRS position data. Only with googling I found out that the mode was realliy SSDV. From first reading I had SSTV in mind. But this was a kind of digital transmission of pictures using RTTY in the end.
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➔ SSTV Pictures from ISS
| 1 minute read
Beginning from Saturday there was another set of SSTV transmission from the International Space Station. During three to four passes on the last 3 days I could decode quite a good set of pictures. Orbit calculation and doppler shift correction was done using Gpredict and the SSTV transmissions were decoded with qsstv. My set of pictures can be found here
➔ ICOM IC-92 GPS feed
| 2 minute read
As I discovered earlier it is possible to feed the ICOM IC-92 with external GPS sources instead of the original external microphone. One way is to use the programming cable OPC-1799 with a null modem cable. Here GPS data can be transmitted to the radio with 19k2 bauds. But as I setup a little interface box using the original cable for the HM-175GPS mic I found out that the two wires RX and TX are not wired up in the spare part that I ordered.
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➔ On D-Star and GPS Modes
| 2 minute read
While experimenting with arpx (see [1]) as a more recent digipeater software in exchange for digi_ned I was searching for a way to gate the GPS position data from the APRS-IS [2] to the local APRS QRG. With the old combination of digi_ned and javAPRS that seemed not feasible in a simple way. And as I wanted to install a software that is under active development I investigated on this a bit further.
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➔ ICOM IC-92 and external GPS
| 2 minute read
The ICOM IC-92 D-Star radio can transmit GPS data while operating a D-Star repeater. In order to receive the GPS signals one would normally have to buy an external microphone with a built-in GPS receiver. This device is rather unhandy and particularly expensive: around 220.00 €. I put the radio into a box on the carrier of my bike. Therefore the GPS mic is not an option. As I already figured out the pinout of the 12pin connector I tried to reverse-engineer the GPS input.
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➔ Disassembly of DMC-TZ22
| 1 minute read
My Panasonic Lumix DMC-TZ22 camera got unusable because a metal part in the SD card slot was deformend. The reason therefore obviously was a not properly attached R/W sliding switch on the side of the memory card. The local dealer abandonned a repair and instead recommended the purchase of a new model.
But as the camera survived a drop from about 1,5m height month ago and it was still working properly I decided to disassemble and repair the SD slot myself.
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➔ ICOM PCR2500 version differences
| 2 minute read
A while ago I got hold of a nice ICOM Scanner model PCR2500 with options for P25 and D-Star decoding. After opening the case to determine which module is needed and where to install it I discovered that my verion was lacking the second slot. So I could not install the UT-122 module for P25 decoding because that could only be installed into the dedicated slot that was not present in this model.
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➔ WRT54G long term issues
| 2 minute read
After running for several years one of my WRT54G devices started to make strange noise. It smelled like burnt electronic components. But it obviously worked as the LEDs glowed when the power supply was plugged in. My first guess was that the voltage regulator in the input has gone up in smoke because the PCB got quiet hot in that area. The noise was obviously generated by pulsating current in the input coils LX1 and LX2.
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➔ fldigi with non-standard ports
| 2 minute read
I really like fldigi as software for digital modes on HF. But one thing that can really drive one mad is that the configuration of port (e.g. serial port for PTT) cannot be saved if it is not named like the legacy ports /dev/ttySX oder /dev/ttyUSBX. You would have to reconfigure this every time fldigi starts. A look into the source code shows that the program looks for these standard ports on startup and puts them into the list of usable ports that you can select from the drop down menu in the configuration options.
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➔ SuperSpeed S328 SSD and TRIM feature
| 2 minute read
A while ago I got myself a new box for routing purposes. I replaced my PC Engines Alix 2D13 with one of its successors APU1C. There was a nice bundle with a SuperSpeed S328 SSD (16GByte), power adaper and case for a shiny price. I set up fli4l and that was runnig fine until …
.. it came down to enabling the TRIM function for SSD hard disks. I updated the busybox to include the fstrim binary and ended up with a broken MBR.
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