20W Magnetic QRP Antenna Loop Antenna For High Frequency Transceiver Icom-705
Couldn't load pickup availability
20W Magnetic QRP Antenna small loop antenna for high frequency transceiver ICOM-705 5-30mhz 76-108mhz 110-150mhz 400-450mhz
This is a portable small loop antenna. It is easy and quick to set up the antenna for your shortwave transceiver. Anti-interference, low standing wave, strong directivity, full frequency band. Thus, allowing you to enjoy multi-band reception and communication indoors, windows, balconies and outdoors.
FM radio also provides excellent reception
Band selection switch, pull up 7MHz, pull down 14-30MHz
The upper knob is the frequency tuning knob, and the frequency tuning value does not change due to changes in the environment.
The lower knob is the impedance matching knob, and the impedance matching value will change due to changes in the environment.
Data transfer: 10W
Use the right angle adapter and double male butt to connect the antenna to the m seat on the back of the radio and stand up or connect the ring body to the connector on both sides of the controller and tighten it, then mount the tripod to the mount on the back of the tuner , open the tripod, place the antenna body firmly on the tripod, and finally connect the feeder (the feeder is attached with a choke, and one end of the choke is close to the small loop antenna).
Now that the small loop antenna is connected to your station, you can now listen.
First, let's introduce the function of the tuner panel. The toggle switch on the left is the frequency band selection switch (upper: 7MHz, lower: 14-30MHz).
The main control knob, the upper knob is the frequency tuning knob, and the frequency tuning value will not change due to environmental changes; the lower knob is the impedance matching knob, and the impedance matching value will change due to environmental changes. (The adjustment range of the two knobs is 180 degrees, and the panel value is 0-12).
To start using the radio, select the desired frequency, then turn the band switch to the desired band position, then adjust the impedance matching value of the lower knob to 6, and then adjust the upper knob to tune. At this time, pay attention to the background noise of the radio. The more resonance there is, the greater the noise floor of the station. At this point, let the radio transmit (cw, fm, am modes are available), pay attention to the standing wave indication, and fine-tune the frequency tuning knob when transmitting. Since the knob of the portable version has no deceleration function, the fine-tuning method must be more delicate, and the smaller the rotation angle, the better.
At this time, it can be observed that the standing wave has obvious changes, but the minimum standing wave ratio is generally not lower than 1.5. At this time, the impedance matching knob needs to be adjusted. It is recommended to randomly adjust the positive and negative 5 scale values, and then repeat the steps of frequency tuning and observing the standing wave ratio. Due to the change of the matching value, there are two possibilities before the comparison, 1: the minimum value of the VSWR decreases; 2 the minimum value of the VSWR increases. If the minimum value of the standing wave ratio becomes lower, the impedance matching adjustment is close to the correct value, and further adjustment is possible. If the minimum value of the standing wave ratio becomes larger,
Repeat the above steps to adjust the VSWR of the antenna to 1.0.
For VHF and UHF bands, the upper knob is fixed to 12 to the end, and the lower knob can properly adjust the impedance resonance.
Note: It is best for outdoor use, indoor use of the antenna as close to the window as possible, in a fully enclosed environment with reinforced concrete, against a wall and other environments, the VSWR of some frequency bands is not ideal.
Advanced skills: When the signal is weak, the direction of the antenna can be rotated to improve the signal-to-noise ratio, which is beneficial to reception. The unique gain lobe of the loop antenna gives it horizontal gain directivity when upright. Using its characteristics, multiple signals in the horizontal direction can be selected in a targeted manner, and the co-channel interference in the horizontal direction can also be reduced. Of course, if the interfering signal is extremely strong, much larger than the useful signal that needs to be received, the weakening effect will not be too obvious, and it can still play a weakening role compared to the telescopic antenna.
The Scope of Use:
SWR: <1.2 (7MHz, 10MHz, 14MHz, 21MHz and 29MHz)
VHF + Aviation Band: 110~150MHz
1X small loop antenna
1X2 meters transmitting antenna
1X5 meters 50 ohm coaxial cable
1. Free Shipping
2. Location: Leicestershire
3. Shipping time: 3-8 buisness days via Royal Mail or FedEx.
Guarantee Period: 1 Years
Returns & Refunds: Customers can return the goods within 60 days of receipt and process quick refund within one day
24-Hour Support: Provide you with timely after-sale support