I « rebuild » my Geiger counter, the SBM-20 tube was initially inside the box, so, i have put this one inside a 32mm diam plastic tube, for more convenience, wired through a XLR3 cable.
The LCD display alternatively, the « count per minutes » and result on: milli Sievert/year or nano Sievert/hour, you can switch off/on the buzzer, also 3 modes on measure are available, 15/30/120 secs.
The uncalibrated signal response is: +1/-1 dB from 1MHz to 450MHz. Input SWR will varry from 1.00 to 1.30, depending on input frequency. To make the SWR good, you need to assemble the input circuit correct and adjust the capacitor.
Input power range: -60 to +30dBm that is 1 nW to 1 Watt.
This instrument can be used and calibrated from 1 kHz and up to 500 MHz. It is possible to measure power relative all the way up to 900Mhz. A software routine can calibrate the 0dBm point at 5 different frequencies to make this instrument accurate within 0.5dBm !! The calibration data is stored in EEPROM so the instrument will remember all, also without power.
At frequencies above 300Mhz this instrument should not exceed inputs over +20dBm (100mW) to keep the good accuacy.
I have recalibrated this device on following frequency, 3, 15, 30Mhz HF, 145Mhz VHF, and 432Mhz UHF , only 5 points are available, the author don’t want and will never add more. sadly.
This is an easy way to power an highly brightness LED for 10 hours, some parts are recycled or was buy from ebay for 1$ or less …
– Solar panel 5v – 0.5A (ebay)
– 5V Mini USB 1A TP4056 Lithium Battery Charging Board (ebay)
– LM2596 DCDC Converter (ebay or dx.com)
– A Li-On 3.7V batteries (recycled from old phone)
– A photo-resistor, 10k pot meter, 1K resistor pull down, highly brightness 10mm LED (white warm), cables, and small box… Continuer la lecture de Revive an old garden lamp with a solar panel→
A lot of informations are available about ESP hardware over Internet … sometimes confusing, here is my experience’s about ESP8266 soldering and flashing, especially ESP-03 SMD version, first i use SMD adapters, Futurlec, 14 Pin SSOP Adapter has a perfect match, and are very cheap, the pin of SMD version didn’t match with standard pin header 2.54mm
