Antenna Handbook

Electret microphone preamplifier module adjustable gain

Electret microphone preamplifier module adjustable gain - Cheer for your project. The fully assembled and tested circuit board has a soldered 20-20KHz electret microphone.
The amplifier has excellent power supply noise suppression, so the amplifier does sound good.
This breakthrough is most suitable for projects that use FFT, such as voice converters, audio recording sampling, and audio responsive projects.
We include a small trimmer potentiometer to adjust the gain. You can set the gain from 25 times to 125 times. Down to about 200mVpp (normally, about 6 inches away),
ideal for connecting to something that requires "line level" input without clipping, or up to about 1Vpp, ideal for reading from microcontroller ADCs.
The output is rail-to-rail, so if the sound is loud, the output can be up to 5Vpp
-Ground GND, VCC to 2.4-5VDC.
-For best performance, use the "quietest" power supply available (on Arduino, this will be a 3.3V power supply).
-Audio waveforms will be output from the OUT pin. The DC bias of the output is VCC/2, so when its
-Completely quiet, the voltage will stabilize to VCC / 2 volts (DC coupled). If you use audio equipment
-AC coupled audio is required, please place a 100uF capacitor between the output pin and input of the device. in case
-You want to connect to an audio amplifier with differential input or including decoupling capacitors,
-No upper limit of 100uF is required.
-The output pin is not used to drive speakers or anything, but the smallest in-ear headphones-you need
-If you want to connect the amplifier directly to the speakers, please use an audio amplifier (eg 3.7W stereo amplifier). What if you are
-Connect to microcontroller pin, no amplifier or decoupling capacitor required-Connect to OUT
-Connect directly to the ADC pin of the microcontroller.
-For projects with audio responsiveness, we recommend using the FFT driver library, which can take audio input and "convert" it to
-frequency.
The fixed gain is 20dB, which can support two power supply modes of 3.3v and 5v.

Z-80 Microprocessor Trainer (Microprocessor Training Kit)

Z-80 Microprocessor Trainer (Microprocessor Training Kit) - This product is a Z-80 microprocessor practicum tool equipped with an 8-bit LED output.
Very suitable for students and students, and hobbyists
Always ask for stock conditions before ordering.
Specification:
CPU: Z80-CPU
RAM: 2 Kbyte and expandable up to 4 Kbyte (6116)
EPROM: 2 Kbyte
Display: 6 digit seven segment
Keyboard: 36 keys (19 function keys, 16 hexa digit keys and 1 reset key)
Krisbow aluminum suitcase packaging
Package contains:
Z80 Microprocessor Trainer
PIO LED Output Interface
AC to DC Power Supply 5V / 500mA
Practice guide and answer key (PDF file)

Complete Digital Stereo Mini FM Transmitter

Complete Digital Stereo Mini FM Transmitter - An FM transmitter with clear audio quality is not inferior to a million-priced transmitter with a range ranging from 2 to 5 kilometers depending on the height
of the antenna. It is suitable for community radio, school radio, shop radio, or for broadcasting within the city, sub-district or village scope.
The advantage of this FM transmitter is that it is waterproof 24 hours non-stop every day, it is equipped with an internal power supply and a cooling fan in it.
Digital channel display 87.5 - 108MHz there is an UP/DOWN button to adjust the empty channel in the respective area.
Features:
FM transmitter ready on air
Stereo audio input L/R
Digital PLL 87.5 - 108MHz
Mini compact design
Power output 5 watts
Internal power supply
Save electricity consumption only 36watt
Sales Package:
1x Stereo FM Transmitter
1x Cable 12 meters
1x Antenna dipole