Tower crane knowledge
Tower crane 1. Advantages: (1) It has a multi-purpose machine (such as mobile, fixed, attached, etc.), which can adapt to the different needs of construction;
Tower crane
1. Advantages:
(1) It has a multi-purpose machine (such as mobile, fixed, attached, etc.), which can adapt to the different needs of construction;
(2) The height of the rise after attachment can reach more than 100m;
(3) The effective operation range can reach 80% of the full range;
(4) It can be loaded in place.
(5) The power is the motor, the reliability and maintainability are good, and the running cost is extremely low.
2. Shortcomings:
(1) The body is huge, except for the light type, it needs to be disassembled, and it takes time and effort to disassemble;
(2) The transfer cost is high, and the use period is short and uneconomical;
(3) Working at heights with high safety requirements;
(4) It is necessary to build a foundation.
3. Scope of application
(1) Construction of civil buildings with high-rise and super high-rise buildings.
(2) Construction of heavy industrial plants, such as the main plant structure and equipment hoisting of the power station, hoisting of blast furnace equipment, etc.
(3) The internal climbing type is suitable for a narrow environment at the construction site.
This article by Tianjin Crane: http:// finishing compilation!
Http://news.chinawj.com.cn
Editor: (Hardware Business Network Information Center) http://news.chinawj.com.cn
Description for RG59 with Power Cable:
Mainly used for the distribution and access of electronic communication equipment, RF transmitter
unit of communication system, building cabling and CATV; the most striking features are broadband
and high speed; currently, also widely used in the multimedia transmission field; conforms to RG59.
Features for RG59 with Power Cable :
|
Specificaitons |
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|
Physical dimensions |
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|
component |
Standard-shield |
Tri-shield |
Quad-shield |
|||
|
inchs |
mm |
inchs |
mm |
inchs |
mm |
|
|
Nominal center conductor diameter |
0.032 |
0.81 |
0.032 |
0.81 |
0.032 |
0.81 |
|
Nominal diameter over dielectric |
0.144 |
3.66 |
0.144 |
3.66 |
0.14 |
3.66 |
|
Nominal diameter over first shield |
0.151 |
3.84 |
0.151 |
3.84 |
0.151 |
3.84 |
|
Nominal diameter over jacket |
0.24 |
6.10 |
0.24 |
6.10 |
0.265 |
6.73 |
|
Nominal jacket wall thickness |
0.03 |
0.76 |
0.032 |
0.81 |
0.034 |
0.86 |
|
Nominal diameter of steel messenger |
0.051(single) |
1.3 |
0.051(single) |
1.3 |
0.051(single) |
1.3 |
|
0.072(dual) |
1.83 |
0.072(dual) |
1.83 |
0.072(dual) |
1.83 |
|
|
Electrial Characteristics |
|
|
Nominal impedance |
75ohms |
|
Nominal Velocity of propagation |
85% |
|
Attenuation(20°C) |
||
|
Frequency(MHz) |
Maximum(dB/100ft) |
Maximum(dB/100m) |
|
55 |
2.05 |
6.73 |
|
211 |
3.80 |
12.47 |
|
350 |
4.80 |
15.75 |
|
450 |
5.40 |
17.72 |
|
550 |
5.95 |
19.52 |
|
750 |
6.97 |
22.87 |
|
865 |
7.52 |
24.67 |
|
1000 |
8.12 |
26.64 |
Coaxial Cable,CCTV Camera Coaxial Cable,RF Coaxial Cable,RG6 Coaxial Cable
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