ATU-100 HF Automatic Antenna Tuner 1.8MHz-30MHz Open Source N7DDC Amateur Radio Communications

ATU-100 HF Automatic Antenna Tuner 1.8MHz-30MHz Open Source N7DDC Amateur Radio Communications

Attention:
The core design information of this antenna tuner comes from its original author N7DDC's automatic antenna tuning open source project.

Description:
The finished kit is purely hand-soldered, providing 3.1 program support with SSD1306 controller, resolution of 128x32 pixels, diagonal 0.91" monochrome OLED display. This circuit contains a set of 7 inductors and 7 capacitors, which allows it to work in a wider frequency range, which can effectively cover the amateur radio range from 1.8MHz to 30MHz.

Technical Characteristics (basic model):
- Allowable supply voltage range: 10-15VDC
- Maximum current consumption: 400 mA
- Maximum working power: 100W
- Maximum possible measurement power: 150W
- Minimum power required to start tuning: 5W
- The smallest possible measurement power: 0.1W
- Measurement resolution for power up to 10 watt-hours: 0.1W
- Measurement resolution for power greater than 10 watts: 1W
- Power measurement accuracy error: ±10%
- Maximum installation inductance: 8.53H inductance
- Minimum installation step distance: 0.05H
- Maximum installed capacity: 1869pF
- Minimum capacitance installation steps: 10pF
- Typical consumption 100-200 mA

Package Included:
- 1 x Set of HF Automatic Antenna Tuner

Note:
- It is assembled and ready to use.
- At present, optional functions include 1-5w start and adjust, 10 seconds screen self-extinguishing/constant light, automatic/manual mode, etc. Please leave a message for optional functions. The default is 5w start and adjust, the screen is always on, manual mode.
- Battery is not included.

Operation Instructions:
Connect the DC socket to a power supply DC 10-15V (inner +, outer -), the panel Power button is in the on position, set radio power to 5W-10W, press and hold Reset/Tune button, screen displays TUNE. At this time, the transmitter transmits continuous power, and the antenna tuner can be adjusted automatically. Short press the Reset/Tune button, the antenna tuner releases the previously adjusted LC relay, which is in the through position.

In consideration of environmental protection and energy saving, this antenna tuner can sleep on the screen after 10 seconds of no action and no emission. If you need this feature, you can contact customer service to change it before placing the order. At present, the antenna tuner works in manual mode, that is, the relay will adjust after long pressing the Reset/Tune button. The antenna tuner can also work in fully automatic mode without pressing a button. After the system detects that the standing wave ratio is greater than 1.3:1 (this value can be adjusted), it will automatically start to adjust. If you need this working mode, please contact us before shipping.

The black and red binding posts are experimentally used for the adjustment of long-wire antennas.

The Ver1.21 version adds SX1308 boost circuit (this part of the component needs to be purchased separately by buyers) in the spare position of the motherboard, and power supply modes can be switched through the reserved SMT pad. And add a fully automatic mode interface to the motherboard to facilitate DIY. Attention: Due to the noise interference that may be generated after adding this DC-DC boost circuit, it is not used as a basis for product quality problems.

SX1308 is a fixed frequency, SOT23-6 enclosed current mode boost converter. The operating frequency of up to 1.2MHz allows the peripheral inductors and capacitors to choose smaller specifications. Built-in soft-start function reduces the start-up inrush current. The internal integrated 80 milliohm power MOSFET, the highest boost efficiency can reach 97%.