bateri utk ham radio

Bateri



Kuasa bateri adalah pentingl untuk operasi emcomm. Kuasa AC biasanya tidak boleh bergantung pada sebarang tujuan dan operasi mudahalih untuk lanjutan jangka masa adalah biasa.

Bateri-bateri mesti dipilih untuk menandingi muatan maksimum peralatan, dan panjang masa yang operasi mesti terus sebelum mereka boleh dicas semula. Adalah disarankan untuk menggunakan "Sealed Lead Acid" (SLA)bateri.

Bateri-bateri SLA tidak seharusnya di nyahcas terlalu rendah misalnya bateri 12VOLT SLA akan rosakkan jika dibenarkan menurun di bawah 10.5 Volts. Haba panas atau sejuk yang melampau  boleh merosakkan bateri-bateri SLA juga.

Bagaimana untuk menghitung bateri Ah ?
Menganggar kuasa 24 jam untuk operasi stesen pangkalan menggunakan mobile rig VHF.

Terima Current 1amp x 24hrs         = 24
Memancar  Current 5 amp x 6 jam = 30
jumlah AH                                            = 54Ah

penggunaan 54Ah Actual .
Pilihan bateri sebenar 54 x 1.2 = 64.8Ah
Pilihan terdekat ialah bateri 60Ah yang mana tersedia ada
dalam pasaran itu.






Pengecas-pengecas Bateri


Anda sepatutnya mempunyai dua atau lebih banyak bateri-bateri. Supaya, satu boleh dicas manakala satu lagi adalah digunakan. Ia terbaik untuk cas secara perlahan semua bateri-bateri tersebut sebagai bantuan mengelak pemanasan lampau dan melanjutkan jangkau hayat bateri tersebut. Secara umumnya,  bateri automatif (sel kering) dan bateri sel basah boleh dicas dengan sebuah kenderaan dan kabel peloncat atau mana-mana punca voltan malar. Jika pengecas bateri yang bersesuaian tidak boleh didapati, mana-mana bekalan kuasa DC voltan sesuai boleh digunakan tetapi diod pengasingan heavy duty mesti menjadi penghubung antara bekalan kuasadan bateri. Ini penting kerana beberapa bekalan kuasa mempunyai satu 'crowbar' atas litar, yang mana jika output voltan litar pintas melebihi satu had voltan tertentu. Voltan output bekalan mesti dinaikkan kepada composate untuk susutan voltan diod.


Voltan pengecas mesti disimpan antara 13.8 dan 14.5 volt. Mengikut kebiasaan yang baik ialah untuk menyimpan pada tahap semasa lebih kurang 1 / 3 kapasiti terkadarnya. Misalnya jika anda mempunyai bateri 7Ah anda patut mengecas ia di tidak lebih daripada 2 amps. Jangka masa untuk mengecas bateri SLA  sepenuhnya akan bergantungan jumlah baki kuasa didalam bateri. Jika bateri hanya 25% dinyahcas jadi ia boleh dicas dalam beberapa jam. Jika kuasa dalam bateri   50% atau lebih daripada ia akan mengambil antara 18 – 24 jam untuk dicaskan.


DC to AC Inverters

Bagaimanapun kuasa dc lebih cekap dan patut digunakan bila-bila mungkin, inverters boleh digunakan untuk peralatan yang tidak boleh secara langsung dikuasakan dengan 12VDC.
Bukan semua inverters sesuai untuk kegunaan dengan radio, komputer-komputer atau jenis tertentu pengecas-pengecas bateri. Inverters terbaik adalah  yang mempunyai “gelombang sinus benar” output. Inverters dengan output gelombang sinus yang diubah suai tidak mungkin digunakan untuk pengecas bateri kecil dan alat gelombang lain alat yang sensitif. Tambahan lagi inverter “Penukaran Frekuensi Tinggi” menjana bunyi bising RF jika mereka tidak ditapis kedua-dua sinar dan pada output ac. Menguji inverter anda dengan bekalan kuasa radio-radio anda dan aksesori-aksesori (walaupun mereka beroperasi berdekatan pada DC) inverters patut dibumikan apabila digunakan, ini adalah untuk keselamatan dan mengurangkan sinar bunyi bising RF.

batteries for amateur Radio

Battery power is critical for emcomm operations. AC power cannot usually be relied 
upon for any purpose and portable operation for extended periouds is common.

Batteries must be chosen to match the maximum load of equipment, and length of time that operation must continue before they can be recharge. It is advisable to use "Sealed Lead Acid" (SLA) battery.

SLA batteries should never be deeply discharge for example a 12Volt SLA battery will be damage if allowed to drop below 10.5 Volts. Exessive heat or cold can damage SLA batteries too.

How to calculate battery Ah ?

Estimate 24hrs power for base station operation on VHF transceiver.

Received Current 1 amp x 24hrs = 24

Transmit Current  5 amp x 6 hrs  = 30

Total AH                                         54Ah

54Ah Actual consumption ...

Actual battery choice  54 x 1.2 = 64.8Ah

The nearest choice is 60Ah battery which is available

in the market.

Battery Chargers

You should have two or more batteries. So that, one can be charging while another is in use. It is best to slow charge all batteries since this helps avoid over heating and extends their over all life span. In general automative and deep cycle batteries can be charged with an automobile and jumper cables or any constant voltage source. If proper battery charger is not available  any DC power supply of suitable voltage can be used but a heavy duty isolation diode must be connected between the power supply and the battery. This is important since some power supply have a “crowbar” over voltage circuit which short circuits the output if the voltage exceeds a certain limit. The output voltage of the supply must be increased to composate for the diode voltage drop. 

The charging voltage must be kept between 13.8 and 14.5 volts. A good rule of thumb is to keep the charging current level to no more the 1/3 its rated 
capacity. For example if you have 7Ah battery you should charge it at no more than 2 amps. The time it takes for SLA battery to recharge completely will depend on the amount of charge remaining in the battery. If the battery is only 25% discharge than it may recharge in a few hours. If the battery in discharge 50% or more than it will take between 18 – 24 hours for charging.

DC to AC Inverters

While direct dc power is more efficient and should be used whenever possible, inverters can be used for equipment that cannot be directly powered with 12VDC. 

Not all inverters are suitable for use with radio, computers or certain types of 

battery chargers the best inverters are those with “true sine wave” output. Inverters with a modified sine-wave output may not operate certain small battery chargers and other wave form sensitive equipment. In addition all “high frequency convertion” inverter generate significant RF noise if they are not filtered both radiated and on ac output. Test your inverter with your radios power supply and accessories (even those operating nearby on DC) inverters should be grounded when in operation, both for safety and reduce radiated RF noise.

Basic Antenna Types

The following discussion of antenna types assumes an “adequate” ground plane is present.

1/4 Wave
A single radiating element approximately 1/4 wavelength long. Directivity 2.2 dBi, 0 dBd.

Loaded 1/4 Wave
The loaded 1/4 wave antenna looks electrically like a 1/4 wave antenna but the loading allows the antenna to be physically smaller than a 1/4 wave antenna. Quite often this is implemented by placing a loading coil at the base of the antenna. Gain depends upon the amount of loading used. Directivity 2.2 dBi, 0 dBd.

1/2 Wave
A single radiating element 1/2 wavelength long. Directivity 3.8 dBi, 1.6 dBd. A special design is the end fed 1/2 wave.

5/8 Wave
A single radiating element 5/8 wavelength long. Directivity 5.2 dBi, 3.0 dBd.

Collinear
Two or three radiating elements separated by phasing coils for increased gain. Four styles are common:

1. 5/8 over 1/4: top element is 5/8 wave and bottom element is 1/4 wave. Directivity 5.4 dBi, 3.2 dBd.
2. 5/8 over 1/2: top element is 5/8 wave and the bottom is 1/2 wave. Directivity 5.6 dBi, 3.4 dBd.
3. 5/8 over 5/8 over 1/4: the top 2 elements are 5/8 wave and the bottom element is 1/4 wave. Directivity 7.2 dBi, 5.0 dBd.
4. 5/8 over 5/8 over 1/2: the top 2 elements are 5/8 wave and the bottom element is 1/2 wave. Directivity 7.6 dBi, 5.4 dBd.

Using more than three radiating elements in a base-fed collinear configuration does not significantly increase gain. The majority of the energy is radiated by the elements close to the feed point of the collinear antenna so there is only a small amount of energy left to be radiated by the elements which are farther away from the feed point.

Please note the directivity is given above for common antenna configurations. The gain depends upon the electrical efficiency of the antenna. Here is where the real difference between antenna manufacturers is seen. If you cut corners in building an antenna, the gain may be significantly lower than the directivity. Larsen uses low-loss materials to minimize the difference between the gain and the directivity in our antennas.

Whip
The vertical portion of the antenna assembly acting as the radiator of the radio frequency.

Dipole 
An antenna - usually 1/2 wavelength long - split at the exact center for connection to a feed line. Dipoles are the most common wire antenna. Length is equal to 1/2 of the wavelength for the frequency of operation. Fed by coaxial cable.

Sleeve Dipoles are realized by mean of the addition of a metallic tube on a coaxial structure.

Printed Dipoles have a radiation structure supported by a printed circuit.

Embedded Omni
These antennas are generally integrated on a base for applications such as access points. This structure could be externally mounted (ex: sleeve dipole) or directly integrated on the PC board of the system (ex: printed dipole).

Yagi
A directional, gain antenna utilizing one or more parasitic elements. A yagi consists of a boom supporting a series of elements which are typically aluminum rods. Named after one of the Japanese inventors (Yagi and Uda).

Panel

Single Patch describes an elementary source obtained by means of a metallic strip printed on a microwave substrate. These antennas are included in the radiating slot category.

Patch Arrays are a combination of several elementary patches. By adjusting the phase and magnitude of the power provided to each element, numerous forms of beamwidth (electric tilt, sectoral, directional ...) can be obtained.

Sectoral antennas can be depicted like a directive antenna with a beamwidth greater than 45°. A 1 dB beamwidth is generally defined for this kind of radiating structure.

Omni-ceiling Mount
Omni-ceiling mount antennas are used for the propagation of data in an in-building environment. In order to provide good coverage, these antennas are vertically polarized and present an omnidirectional pattern in the horizontal plane and a dipolar pattern in the vertical plane.

Parabolic
An antenna consisting of a parabolic reflector and a radiating or receiving element at or near its focus.

Solid Parabolics utilize a dish-like reflector to focus radio energy of a specific range of frequencies on a tuned element

Grid Parabolics employ an open-frame grid as a reflector, rather than a solid one. The grid spacing is sufficiently small to ensure waves of the desired frequency cannot pass through, and are hence reflected back toward the driven element.

For Sale....2nd hand

For Sale....

Item: Radio Transceiver
Description: Mobile/Portable used
Brand: Icom
Model: IC2200H
Power Output: 65Watt
Accessories: Larson antenna,5m antenna cable,Bracket
Condition: 9/10

leh contact 9M2JEN