purchase guide:
The two options are K-180 antenna, GA-490 antenna.
Both antennas are excellent works, and the performance indicators are the same. Produced by different factories, the GA-490 antenna is more cost-effective, and the K-180 antenna is more refined.
Below is a link to the GA-490 antenna:
https:///item/1005003961483491.html
K-180WLA is upgraded again without price increase. The 10-meter-length feeder is upgraded to aluminum platinum plus pure copper dense mesh double-shielded feeder, which has better shielding effect and lower loss. The latest version of the preamplifier adds FMDX HF switch to adjust the FM band gain (FM The strong signal area reduces the gain of the FM band and increases the gain of the HF band).
Note:
Ordinary express (for example:
AliExpress Standard Shipping, etc.) are shipped with battery; express logistics (DHL, Fedex IP) do not come with battery, you need to bring your own battery.
Testing video：
https://v.youku.com/v_show/id_XNDU0NzYzMTE1Mg==.html
https://v.youku.com/v_show/id_XNDUzNTk2ODU1Mg==.html
https://v.youku.com/v_show/id_XNTEwNzY4Njg1Ng==.html
K-180WLA (upgraded and improved version) has higher receiving dynamics and signal-to-noise ratio, and can tolerate -10DBM signal strength unsaturation. This is an indicator that the copycat version will never reach, all original design and manufacture
P.BOX has: anti-reverse battery protection, over-charge, over-current, short-circuit protection at the antenna end, complete protection circuit, all the shells are numerically-precision processed, PCB high-frequency design, feeder high-density dense copper pure copper 50-1.5 feeder, materials used Create an ultra-high cost-effective antenna for the entire network.
P.BOX has a built-in 3.7V 18650 flat head lithium battery. No external power supply is required. The MICRO USB charging port is compatible with 5V charging heads and charging cables of Android phones. Convenience. UHF low-noise preamplifier is used. The gain flatness is very good within the ultra-wide operating frequency of 0.1-180MHZ. It provides a gain of about 20DB, even when working to 450MHZ gain, there is still about 8.9DB. The receiving frequency covers long wave, medium wave, short wave, FM broadcasting band and VHF aviation band. The small ring diameter 55CM is simple to set up. It can be set up outside the window, balcony, terrace and roof. It is best not to be surrounded by the surrounding area. It is very suitable for broadcasting with limited space. Lovers erected. All the screws of the antenna are made of 304 stainless steel, and the preamplifier box is fully waterproof, which can be used for long-term outdoor wind and rain. Suitable models include Desheng S-2000 PL-660 PL-880 ICOM R71E YAESU FRG-8800 and all short-wave receivers, especially for SDR receivers.
Note: The antenna is equipped with a dual SMA male adapter cable, an SMA to 3.5 plug adapter cable, and an S2000 BNC adapter, which means that your radio can be used with SMA female, BNC, and 3.5 jacks. Requires additional accessories. Receivers for other interfaces need their own adapters.
The antenna includes a ring oscillator (304 stainless steel), an RF.BOX preamplifier box, a P.BOX feed box, two P.BOX fixing clips and screws (304 stainless steel), and a dual SMA male adapter One (one meter in length), one SMA male to 3.5 plug adapter cable (one meter in length), one Micro USB 2A charging cable (one meter in length), one TNC male and SMA male 50-1.5 feeder cable (10 meters in length) ), Two antenna fixing brackets (304 stainless steel). Free 3 PVC mounting brackets, 2 butt-throughs and 1 tube cap.
Complete set of accessories:
K-180WLA antenna installation and usage instructions
K-180WLA is a wideband loop receiving antenna. The preamplifier uses ultra-high frequency low-noise devices. The noise is low and the gain is about 20DB. The small loop diameter is 55CM. The excellent receiving directivity can effectively avoid interference sources and make the received signal clearer and more effective. Improve the received signal strength and signal-to-noise ratio. The working frequency is 0.1MHz-180MHz covering the long-wave, medium-wave and short-wave, FM broadcasting and VHF aviation bands, and the working voltage is DC 5-12V. The charging voltage of P.BOX is DC 5V (remember not to charge higher than this voltage, otherwise it may damage the circuit and other risks), the charging interface is a MICRO USB socket (common with the 5V charging head and data cable of Android phones), and the charging current is 1A Fully automatically stops. The output voltage of the feeder box is 9V, and the internal isolation circuit is designed to effectively suppress in-band interference and make the output DC voltage more pure. A built-in 3.7V 18650 flat-head lithium battery, the feed box has: overcharge, overcurrent, overdischarge protection and short circuit protection of the antenna feed output terminal.
The receiving direction of FM and aviation band VHF is as shown in the figure below. The receiving direction of HF shortwave is reversed by 90 degrees and opposite to VHF.
Connection installation method:
Erection requirements:
K-180WLA is conditionally installed as far as possible in the unobstructed area around the roof. Indoor use is not recommended, because various indoor interference and building shielding will cause serious signal attenuation (especially in the high band), which leads to poor indoor effects. the reason. If it fails to meet the requirements, try to install it outside the balcony or window, but the antenna cannot be installed against the wall or the anti-theft net. It must be extended to a distance of more than 1 meter from these objects (the farther the better), and try to stay away from the power line and If there are communication base stations nearby, these interference sources should be avoided as much as possible.
After the antenna is set up, turn the antenna to make the received signal the strongest and the lowest noise floor. If the strong signal is overloaded during normal reception, you can manually adjust the radio&x27;s far and near switch or RF gain adjustment to attenuate the strong signal. The radio reception is selective and Radios with poor dynamics are not recommended, because poor radio dynamics will cause the signal-to-noise ratio to deteriorate due to strong signal overload, and the reception effect will be worse.
Regarding the difference between FM mode and AM mode, FM is the frequency modulation mode, which is basically one of the most commonly used modulation modes for local broadcasting. The operating frequency is 88-108MHz. The advantage of this mode is that as long as the signal exceeds the receiver&x27;s receiving threshold, it will not When there is noise, it occupies the frequency bandwidth of the spectrum and the sound quality can reach a high-fidelity level, and it can be continuously broadcast locally throughout the day. The AM mode is an amplitude modulation mode, which is usually a mode used for shortwave broadcasting. It occupies a narrow frequency band and allows the HF band with limited spectrum resources to accommodate more broadcasting stations. The sound quality is relatively only for broadcasting requirements. Shortwave is Long-distance transmission through ionospheric reflection, so the ability of ionospheric reflection and transmission is different in different seasons and different times. Generally, 500K-1600K medium wave will propagate at night, while shortwave will only propagate better at 6-9 megabits at night. During the day, it is good for 9-15 megabits to propagate, for high-band in summer, and for low-band in winter, because this is determined by the characteristics of ionospheric propagation. The low frequency of shortwave is easy to be caused by common mode differential mode interference produced by household appliances, energy-saving lamps and other industrial equipment. This is a weakness of shortwave (especially the most serious interference from electric vehicle chargers), coupled with ionospheric reflection and propagation It is impossible to be stable all day, which leads to the shortwave effect is definitely not as good as FM radio.
Little knowledge about active antennas: Many people think that the higher the gain, the better. In fact, this is a misunderstanding. The higher the gain of the preamplifier, the spatial noise is also amplifying. If the noise floor exceeds S9 or more, it can’t be said to improve the reception effect. (Signal-to-noise ratio), the signal is strong, the noise floor is large, the signal-to-noise ratio is worse, so it is not easy to make an active antenna simple, and it is necessary to amplify the useful signal while also allowing the noise generated by the device itself. If it is small and dynamic, it must be large. In addition to circuit design, the use of devices is also the most important factor, and low-noise devices are used. Only in this way can the effect of improving the signal-to-noise ratio be achieved. The most important indicator of an active antenna is the signal-to-noise ratio. An excellent active antenna is the signal-to-noise ratio that improves the signal strength while effectively improving the received signal&x27;s signal-to-noise ratio.
Connection and installation method of ring vibrator and PVC bracket:
Use a 3.7V 18650 flat-head lithium battery
Precautions:
The P.BOX feeding box is compatible with the 5V 1A charging head of the mobile phone. Insert the MICRO USB charging cable. The charging indicator is on and the charging current is about 1A. The normal charging time is about 5 hours. It can be used continuously for about 40 hours when it is fully charged. The antenna can be used normally when charging, but the overcurrent and short circuit protection circuit does not work It is not recommended to use while charging The charging voltage cannot exceed 5V. Overvoltage will cause permanent damage to the circuit and may cause other safety risks
In addition, the P.BOX feed box battery has an anti-reverse connection protection circuit, and the reverse connection of the battery&x27;s positive and negative poles will not damage the circuit. However, if the positive and negative poles of the battery are reversed, please change the positive polarity immediately. If the battery is reversed and then recharged, the circuit will be damaged
The antenna end of the P.BOX feed box is connected to the antenna preamplifier box, and the radio port is connected to the radio or receiver. If the antenna does not work properly if the antenna is connected incorrectly, please make sure that the power switch is turned on after the connection is correct, and the PWR power indicator will light up The antenna is now working normally.
After the protection circuit is activated, the PWR light is off. At this time, remove the short circuit and switch the power switch again to release the protection state.
When the antenna is installed and used, the metal part of the small ring should not touch other objects (especially leaves and other metal objects such as anti-theft nets), otherwise the preamplifier may be damaged
This antenna is an active antenna, it is forbidden to transmit The transmission must damage the preamplifier
