studentkra

I received an HMC253 (DC-2.5 GHz) board today for $8. I also have an ESP8266 for $2. These are the cheapest materials from which you can assemble an antenna switch controlled via USB.

Yes. This is bad frequency! Your should not listen it (((

I successfully use an external attenuator for KiwiSDR1. The attenuator is assembled on the PE4302 board and ESP8266. Control is via USB connection to KiwiSDR. The attenuator works in a simple automatic mode. At night, a signal attenuation of 15 dB is used. In the daytime, the signal attenuation is set to 5 dB. An algorithm for controlling the attenuator in an intelligent mode with feedback by reading the ADC_overvoltage values ​​was also developed. Attenuation is selected automatically several times per minute so that ADC overloads are as small as possible.

https://forum.kiwisdr.com/index.php?p=/discussion/2996/external-attenuator-for-kiwisdr-1

Hello. KiwiSDR stopped working after the thunderstorm. The power supply goes into protection. There is a short circuit on the KiwiSDR power connector.

The BeagleBone board also stopped working. Separately from the KiwiSDR, the BeagleBone shows no signs of life and the TPS65217C chip is very hot.

The problem was not only in the failed transformer T301. The 5V power line had a resistance per mass of 5 ohms. 

All linear stabilizers are out of order. Three pieces LP5907 and LMR10530Y. Moreover, the LMR10530Y was pierced through. That is, the 5V input was connected to the 1V output.

For further diagnostics, the stabilizers were replaced with similar ones.

KiwiSDR is working, but additional testing is required.

I made a short video of this repair.

https://youtu.be/6Vtmoc8Z-Eg?si=PIFDW3fEnpm8zuwE

I have three SDR receivers and a linear power supply for three channels of 5 volts. I'm using an LT1084ADJ in a TO220 package. It has been working around the clock for over a year now. And I think the LT1083/1084/1085 stabilizer is a very good and cheap choice.