For a long time, I did not create any post related to the sdr.gudynas.lt project, although during the last year, many improvements and changes have been made, which in one way or another affect the receiver’s operation. So I will try to put together everything that was improved in this project.
New Router
Upgraded old TP-Link TL-WR1043ND router to Mikrotik hAP ac²
The network connection scheme has not changed, apart from the fact that the default route is now via gateway Huawei B525s-23a 4G LTE router which is connected to Mikrotik via WiFi n standard, and Huawei itself is located in the house. https://sdr.gudynas.lt is, as before, accessible through the Cloudflare zero trust tunnel.
Upgraded Grounding, added Surge protection
First, the grounding loop was removed. In addition, the antenna grounding and power line groundings were connected together, although there are two grounding points. Now they are separate. An Antenna feed arrester is additionally placed on the antenna coaxial cable.
Fearing a lightning strike and its entry into the common electrical network, a Power Surge Protective Device SPD Arrester is placed at both ends, both in the outdoor box, where the SDR receiver is located, and inside the building, where the electrical input is located. Together with it also installed Current drain relay.
The antenna mast and all other elements from here have their own separate connection points directly to the ground.
Ready for Winter
Today (2024-11-09) a mini-heater was installed in the box. Last winter, miraculously, the PC and other elements in the outdoor box survived successfully, the strangest thing is that even the HDD in it is still alive! Last winter, when the outdoor temperature reached -20 degrees Celsius and below, I noticed that the CPU temperature in system monitoring showed 0 degrees (most likely the CPU sensor or the system software does not show below 0), I have a suspicion that even with a slight load, the CPU temperature was minus. (You don’t even need liquid nitrogen to overclock the cpu 😂) Now installed 250W mini heater it will maintain a minimum temperature of 15 degrees C inside the box. when the heater turns on, the temperature inside instantly (in less than 1 minute) reaches +27-28 degrees Celsius. The only problem last winter was that when the temperature outside was -10 or below, the PC wouldn’t start when the power went out and when it came back on. I don’t know exactly whether it’s because of the HDD or because of some other nuance. However, it was possible to start several times by disconnecting and reconnecting the power supply remotely.
Temperature inside box live from the box camera:
What about hot summer days?
On hot summer days, when the box was heated directly by the sun and the temperature in it reached 40+ degrees Celsius, then the fan in it automatically turned on and worked until the temperature dropped to 30 degrees Celsius. There were days when the fan turned on at noon and stopped only after the sun went down. however, we did not face any PC overheating problems.
1-Phase Two-Stage Filter, Broad Band Attenuation
When a filter is installed, it isolates the PC from EMI noise present in the power network, resulting in an even cleaner spectrum in the SDR receiver, with fewer unwanted spectral artifacts visible.
What are future plans?
I have several unconnected sdr receivers, I would like to connect them to the same antenna, but I need to make a good antenna splitter that would not damage the receivers working next to it and would not have a large signal level loss. It is necessary to separate the SAT frequencies 242-270~MHz on a separate receiver, because I noticed that most of the time it is the SATCOM satellite that is being listened to, which means that new visitors do not have the opportunity to listen to another frequency they want, because usually after changing the frequency to another, the existing visitors switch to satcom. If you have a suggestion, a request, or a question, I will always be waiting for your letter through the contact form, as well as your comment. Also, if you know of a good, ready-made wide-frequency range splitter, I’ll be waiting for your suggestion!
What does this sandwich look like now?
Recent Comments