To know more about the connector of the antenna and the cable


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About the connector:

Now we will have a joint of male and female

Male that is “J” connector.

Female that is “K” connector.

So how to combine them to model, first we used the model species listed:

SL16 interfaces; earliest car radios for a variety of engineering and early Taichung, the interface process is simple, commonly used in ordinary connection, advantages are: durable pass.

L16 interfaces; evolved from the SL16, waterproof anti-leak of the interface function better, now used for high-end machines.

BNC connectors; BNC interfaces also known Q9, this interface easy disassembly, now used to monitor, detect some of the finest instruments often require replacement of equipment at any time.

TNC interfaces; the Marantz 260, 378, etc. Kenwood’s machines evolved, now out of the new machine has no need.

MOTO interfaces; was MOTOROLA company developed a vehicle-mounted radio equipment, a stage had been popular, and more to the BNC connectors, is the only machine compared with the old models use only.

SMA interface; this stage, the most common handheld radio interface, which is very common.

To know about the cable:

Amateur operation is generally limited to low power ( less than 100W) and low- frequency voltage ( less than 1KV). Generally do not consider the capacity of the cable . When using more than 100W of power shortwave radio , coarse cable should be used (for example, -7 ) , in order to avoid the heat .

Common coaxial 50 in Europe, 75 in Europe, three kinds of nominal impedance of 100 ohms . 50 amateur communications common in Europe, although its efficiency is not the highest. In the selected feeder impedance ( 50 ohms) after the key is to choose the thickness of the feeder , such 50-3,50-5,50-7 so . Considering usually based on the expected cost of cable and line attenuation . Specific approach is this:

1. first length of the cable estimation required , combined with the use frequency, location , antenna uses ( for normal radio or repeater ) , etc., to determine the total gain antenna system. Can then determine the maximum tolerable attenuation of the feeder according to the antenna gain . The total gain antenna system recommended as : 144MHz repeater station : 4dB; 144MHz Base Station : 3dB; 430MHz relay station 5dB; 430MHz base station 3dB.

2.depending on the length of the maximum allowable attenuation cable , feeder strike allowed decay constants.  Decay constant amount of attenuation (dB) ÷ line length (m). Decibels per meter.

3.According to the permit obtained decay constant , check the performance of manual coaxial cable , select the attenuation constant given frequency to allow the decay constant of less than coaxial .

Example 1: the actual needs of the cable length of at least 30 meters , 10 roof antenna is located , is a pair of fiberglass antennas 8dB will be used for a very important 144MHz repeater. So, in order to ensure that the effect of relay stations ( communication distance can be accounted for in accordance with the required total air attenuation , then Calculating the total gain antenna system. Amateur conditions can lookup an estimate ) , antenna system needs a total gain of 4dB . The loss of the connector is not considered to require the feeder attenuation of less than 8-4 = 4dB.

Known feeder length of 30 meters , was allowed to decay constant of 4 ÷ 30 = 0.133dB / m. Check the manual cable shows , SYV50-7 -type coaxial cable to meet the requirements , so choose 50-7 coaxial enough.

Example 2:Same as in Example 1, the antenna gain to 10dB, frequency to 430MHz.

Solution:a total estimate of the actual situation antenna system gain is 5dB, feeder attenuation requirement is less than 5dB. Allow decay constant of 5 ÷ 30 = 0.167dB / m.

At 430MHz, the same cable , attenuation will be greater than 144MHz. Check cable manual  SYV50-12 was found to meet the requirements, so the selection of 50-12 feeders. This feeder is more expensive, if the economy can not afford , then 50-9 is the only choice .


Sample/Wholesale
Price
Shipping
Carrier
Buy it Now
1 pcs sample
USD
/pcs
USD
Airmail 25days

pcs
USD
/pcs
USD
Airmail 25days


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