REDOT-2017A 1.6MHz-60MHz Digital SWR Meter HF Shortwave Portable Standing Wave Radio Meter with SL16-KF Connector

REDOT-2017A 1.6MHz-60MHz Digital SWR Meter HF Shortwave Portable Standing Wave Radio Meter with SL16-KF Connector

Description:
- The portable large red dot series standing wave meter adopts a 3 1/2 bit segmented retro-reflector LCD screen for display, which can display clearly in strong sunlight during the day or with backlight assistance at night. The contrast, clarity, and readability under strong light are far superior to dot matrix LCD screens, which is most evident when measuring antennas outdoors.
- The all metal black spray painted shell made of 1mm thick steel plate, although not very beautiful, is sturdy and durable. HAM actually threw it in the toolbox along with chisels, axes, saws, and other tools.
- The short wave adopts an M-type (SL16) connector, which is turned and not a common casting process. The center conductor is welded to the PCB in a 1/2 eccentric manner, effectively avoiding the situation of copper coating on the PCB that is prone to occur in ordinary microstrip structures. The outer conductor is directly soldered onto the PCB, effectively reducing the distributed inductance and achieving very low reflection loss.
- The power supply uses three 7th AAA batteries, which are very energy-efficient. There is no problem using lithium-ion batteries and alkaline batteries, but from an environmental perspective, it is recommended to use green and environmentally friendly carbon batteries.
- A prominent red button can complete operations such as turning on and off the power, turning on and off the backlight, and maintaining the display. There are no complicated menu selection and setting operations, and there is no need for the cumbersome process of using switches to select calibration tests and lookup tables like pointer meters. As long as the signal is emitted, the standing wave ratio can be seen instantly, without the lag and dragging feeling of other digital meters. This relies entirely on excellent measurement and display software design, with strong real-time measurement, fast and stable display, and no constantly jumping numbers. The software algorithm uses digital filtering, peak tracking, oversampling and other techniques, and compensates for the non-linearity of the detection diode by 1000 points, making the measurement accuracy of standing wave ratio far superior to similar products. HAM once used large red dots to observe whether there were birds on its outdoor antenna.

More Information:
- http://pan.baidu.com/s/1mh4lkMk

Specification:
- Maximum power: 199W
- Power error: ±5%
- Standing wave display: 1.00 ~ 19.9
- Working frequency: 1.6MHz - 60MHz
- Directionality: >30dB
- Display screen: 3 1/2bit LCD
- Battery: AAA x 3 (not included)
- Power consumption: < 3mA (backlight off); < 10mA (backlight on)
- Size: 70 x 68 x 37mm
- Net weight: 280g

Package Included:
- 1 x SWR Meter

Note:
- Battery is not included.

FAQ:
Q: Can't turn on after pressing the big red dot, or does the backlight flash when turned on and then turn off?
A: This is due to low battery voltage and the battery is depleted. Please replace the battery.

Q: What is the minimum measured power?
A: The measurement process of a digital standing wave meter is different from that of a pointer meter. A pointer meter is converted by drawing a standing wave reading scale, so a minimum measurement power is required to drive the pointer of the meter head to the full position in order to convert the standing wave reading using the scale. A digital meter samples both forward and reverse signals at the same time and automatically calculates the standing wave ratio. There is no minimum measurement power limit, but when the standing wave is very small, the reflected signal is smaller. Measuring with a larger power can be more accurate than measuring with a smaller power. For example, reading with 0.1W power is sufficient, but measuring with 1W power will be better.

Q: Does ambient temperature have an impact on measuring transmission power?
A: The significant difference in ambient temperature has an impact on the measurement of power. Instrument calibration is performed at room temperature around 20 ℃. If the temperature is too high, the measured power will be biased, and if the temperature is too low, the measured power will be biased, which has little effect on standing wave measurement.

Q: How to accurately measure the standing wave ratio of a handheld antenna?
A: The handheld antenna is usually directly connected to the handheld platform for use. Although a standing wave meter can be connected in series through an appropriate adapter for measurement, the working state of the handheld antenna has changed, and the measurement result is not significant, or in other words, the result is not the standing wave ratio of the handheld antenna on the handheld platform. It is recommended to install the handheld antenna on one end of an iron can, and connect the feeder from the other end to the ANT end of the standing wave meter to simulate the actual working state of the handheld antenna. Pinch the handheld antenna with one hand to read the reading, and hold the can with the other hand to change the position and observe the effect on the standing wave ratio of the antenna.

Q: What is the difference between using a power meter standing wave meter and measuring antenna standing wave with a network analyzer (or antenna analyzer)?
A: A network analyzer (or antenna analyzer) is an offline measurement tool typically used during the antenna design and production phase to comprehensively assess the matching status of the antenna. A standing wave meter is an online measurement that measures the actual conditions in use, usually used during on-site installation, commissioning, and maintenance of the antenna feeder system.

Q: During testing, sometimes the numbers on the standing wave meter fluctuate frequently. Why is that?
A: There are two situations where the number changes rapidly during measurement: 1. When the power reading jumps, it indicates that the output power of the transmitter is unstable, and the transmission power is related to the supply voltage and current, as well as the heating situation of the power amplifier. During AM and SSB, the output power is already changing. At this time, the instantaneous maximum power tracking method can be used to measure the (PEP power) 2 standing wave ratio, which keeps changing. This indicates that there is significant interference in the measurement environment, such as indoor reflection, personnel movement, etc., which can affect the standing wave of the antenna during operation. Pointer tables or tables with slow response cannot detect this effect.