National standard: GY/T 135-1998
Used for CCTV system below 1GHz, shared antenna system (CATV/MATV) as branch line and subscriber line, as well as connecting line or internal wiring of other high-frequency machines
High foaming degree, low dielectric constant, low capacitance, uniform impedance, high transmission rate, low attenuation constant, good anti-interference performance, good moisture resistance, stable structure, long service life, good flexibility, small bending radius, etc.
What is physical foaming ：
The insulating medium layer is filled with inactive nitrogen gas to form a fine and uniform microporous structure, and the micropores are not connected to each other, similar to one sealed chamber. It has the advantages of high foaming degree and no foaming agent residues of polar molecules, so it has excellent transmission performance and is suitable for trunk cables, branch cables, user cables and network connections. Because it is impermeable to water and air, it has particularly stable performance and long service life.
Sheath layer: Material - high quality PVC/ST4
1-2-3-4 Shielding layer: 1. One layer of high quality aluminum foil composite tape; 2. Two layers of tinned copper braid;
3. Three layers of high quality aluminum foil composite tape; 4. Four layers of tinned copper braid
Insulation Layer: Material - Physically Foamed Polyethylene
Conductor: Material - oxygen-free copper
| Product Standards | Product number | Product Specifications | Number of conductors N | Conductor diameter mm | Average thickness of core wire mm | Weaving mesh X | Weave density % | Sheath outer diameter mm |
| GY/T135-1998,SJ/T11138.1 | SYWV | 75-5 single core (A+B)160AL | 1 | 1 | 1.9 | 8 | 92 | 7.5 |
| GY/T135-1998,SJ/T11138.1 | SYWV | 75-5 single core 96AL | 1 | 1 | 1.9 | 8 | 67 | 7.2 |
| GY/T135-1998,SJ/T11138.1 | SYWV | 75-5 single core 128AL | 1 | 1 | 1.9 | 8 | 81.6 | 7.2 |
| GY/T135-1998,SJ/T11138.2 | SYWV | 75-7 single core 128AL | 1 | 1.66 | 2.8 | 8 | 69 | 10.3 |
| GY/T135-1998,SJ/T11138.2 | SYWV | 75-7 single core 144AL | 1 | 1.66 | 2.8 | 8 | 75 | 10.3 |
| GY/T135-1998,SJ/T11138.3 | SYWV | 75-9 single core 144AL | 1 | 2.15 | 3.43 | 8 | 70 | 12.3 |
| GY/T135-1998,SJ/T11138.3 | SYWV | 75-9 single core 160AL | 1 | 2.15 | 3.43 | 8 | 75.2 | 12.3 |
Electrical performance technical requirements
| project | Insulation resistance | Characteristic impedance | decay constant | return loss | Shield attenuation |
| Test conditions | 500（DC）20℃ | 200MHZ | |||
| unit | MΩ·km | Ω | dB/100m | dB | dB |
| SYWV-75-5 | ≥5000 | 75±3.0 | 5HMZ≤2.2 | 300MHZ and below ≥20 300MHZ and above ≥18 | 5HMZ≥60 |
| 50HMZ≤4.8 | 50HMZ≥60 | ||||
| 200HMZ≤9.7 | 200HMZ≥70 | ||||
| 550HMZ≤16.8 | 500HMZ≥70 | ||||
| 800HMZ≤20.3 | 800HMZ≥70 | ||||
| 1000HMZ≤24.2 | |||||
| SYWV-75-7 | ≥5000 | 75±2.5 | 5HMZ≤1.5 | 300MHZ and below ≥20 300MHZ and above ≥18 | 5HMZ≥60 |
| 50HMZ≤3.2 | 50HMZ≥60 | ||||
| 200HMZ≤6.4 | 200HMZ≥70 | ||||
| 550HMZ≤10.7 | 500HMZ≥70 | ||||
| 800HMZ≤13.3 | 800HMZ≥70 | ||||
| 1000HMZ≤15.1 | |||||
| SYWV-75-9 | ≥5000 | 75±2.5 | 5HMZ≤1.2 | 300MHZ and below ≥20 300MHZ and above ≥18 | 5HMZ≥90 |
| 50HMZ≤2.4 | 50HMZ≥90 | ||||
| 200HMZ≤5.0 | 200HMZ≥100 | ||||
| 550HMZ≤8.5 | 500HMZ≥100 | ||||
| 800HMZ≤10.4 | 800HMZ≥100 | ||||
| 1000HMZ≤11.9 |
National Service Number
CN